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1. MEASUREMENT CIRCUIT CELLAR Jo x THE COMPUTER ng APPLICATIONS Ray J OURN AJ Graphics amp Video Time Domain Reflectometer Overlay Text on Video October November 1992 Issue 29 B aUL CUE Te AN HDIBROAIINK A Look at Next Year e re approaching the end of another editorial year and many of you are anxious to find out what we have in stare for the next year Before fist the upcomingithemes lel me take a moment to encourage you to look at the ist with an eye toward writing an article Does one of the themes come close to what you do in your everyday job Perhaps you just finished a project that relates to one of the topics lf so chances are you ve leamed a few tricks that would surely benefit your felow readers Don t assume that just because you re comfortable with a basic concept everyone else is just as comfortable Write an article to show off what you know and everyone will benefit from your knowledge For example if you work with analog circuits all day long your expertise can go a bng way in helping someone whose jcb doesn t extend mush past bits and bytes What s that You ve never written an article and wouldn t know where to begin Nonsense Bounce yourideas off us and we ll be happy to work with you to structure a welt written article in no time What s important is that you know ywr stuff and youtake that first step by contacting us with your ideas You may call me at 203 875 2
2. B03X 805X In ircuit Emulator 695 995 t 8031 68HC11 7 INSTEAD OF THOUSANDS 1 800 972 3733 FREE EVALUATION VERSION 14 DAY NO HASSLE MONEY BACK GUARANTEE EZ ACE the only truenext generation in circuit emulators from AMS are the most complete and highest performance PC based in circuit emulators withthe maximum DOS performance in a full windows like graphical user interface A 5 Performance Quality Ease Advanced Features e 64K of Emulation memory 803 1 32 5 1 52 535 SS2support e 84 000 Breakpoints HC11A8 E9 811E2 Support e Trace buffer CMOS support 12 MHZ and higher clock 7 User test probes Source level debugging Symbolic debugging C and assembly Modem windows like user language interface Advanced Microcomputer Systems Inc 1321 NW 65th Place FT Lauderdale FL 33309 305 975 9515 FAX 305 975 9698 124 The Computer Applications Journal Issue 29 October November 1992 37 Add Text Overlay to Any Video Display All the latest VCRs have on screen programming in an effort to simplify the notorious task Now you can have your HCS II or any other computer send you messages while you re watching your favorite TV show 40 ISSUE 29 October November 1992 SPECIAL SECTION Bill Houghton uppose for the moment you ve built and installed the HCS II home control system described primarily in issues 25 and 26 February March and April May
3. 150 75 MVDISK3 1 44m 195 Quantity discounts WORLOS SMALLEST PC ROBOTS ALARMS RECORDERS DOS THREE EASY STEPS 27 x QTY 1 PC Develop on 2 Download to SBC 95 3 Burn into EPAOM SGL QTY LCD INTERFACE KEYBOARD INPUT REAL TIME CLK BATTERY OR 5V 2 PARALLEL 3 SERIAL PC TYPE BUS BIOS OPTION FREE SHIPPING IN U S 5 YEAR LIMITED WARRANTY Box 850 Merrimack NH 508 792 9507 84 Issue 29 October November 1992 DOSIN ROM i 95 PROGRAMMER 00 ROMS FOR SBC OR MVDISK PROGRAM 2764 27010 EPROMS 8088 SINGLE BOARD must have made quite a sight first careening into their parking lot then dashing into the lobby waving my 180 board and demanding to speak to the marketing manager H owever the receptionist remained calm called the appropriate authorities not the police and it wasn t long before was back on the road this time clutching some real gems 55 ns EPROMs Back at my lab programmed a 55 ns chip and plugged it in I success fully got into high speed mode and started exercising my test program first with three wait states then two then one Then for the big test zero wait states Crashola darn WaferScale has 45 ns EPROMS and they ll even be offering 35 ns soon Therefore knew the simplest fix would be to continue plugging in ever faster memories until it worked But now my curiosity was piqued and knew I wouldn t sleep until I snuffed
4. Complete interface between parallel port and TW523 or PL513 modules ae ASSEMBLY Sane c e Performs all X 10 transmit and receive functions r II Bus d Circuits Detects AC power loas HIGH LEVEL ry Simple interface and timing operates even in interpreter BASIC LANGUAGES y i Systems R Low power only 1 8 mA 5 V Products PLIX chip and PLIXEVALUATION Services data sheet 20 BOARD 100 qty OEM 12 1 waluation we have produced Be Assembly ago 712 fermen treo aliel print The PLIX EKit in e Repair Call 1 800 635 3355 Budes Hix chb anddata shoee PCB with n 7 components application note and PC mM eo Tost or Write for a PLIX data sheet compat bio shunt katk SPECIAL INTRODUCTORY PRICE 4 Add 20 for TW523 X IO transceiver module 29 00 Analog sold with PLIX EKit only G Digital e Microprocessor a PLIX Engineering BIDIRECTIONAL 18 PIN DIP Manufacturing _ Standard Custom Semi Custom 284 Kennedy St Iselin NJ 08830 MICROMINT INC 908 283 4925 203 871 5170 FAX GOs 872 2204 132 See us at the Embedded Systems Conference Booth 919 133 54 Issue 29 October November 1992 The Computer Applications Journal X 10 18 a trademark of X 10 USA inc Listing 2 The se tpa 7 routine transforms HLS values to RGB and calis the video BIOS to bad VGA registers with the RGB values include lt dos h gt define VIDEO_IO 0x10 float delx 1 6 xl
5. 92 of the Computer Applica tions Journal In issue 27 Jung July 92 Ed Nisley described an add on LCD output device as a way to obtain information about the status of the system and its various nodes It s a nice addition to the network but useful only when you re near to the display module What do you do if you re across the room watching TV settled into your favorite armchair You could get up and venture across the room Or if you build the interface described in this artide you could hit a button on your HCS II IR renote and see network information displayed on your TV set overlaid onto the program you are watching This artide describes an On Screen Display OSD terminal for HCS II we ll call it TV Link to match the other HCS II modules that allows color text characters to be displayed on top of a background color video signal The terminal is built around the Philips Signetics 87C054 OSD microcontroller FEATURES OF 87C054 The 87C054 is an 80C51 based microcontroller designed to provide an advanced OSD for TV and video appli cations It can produce characters in eight foreground and eight background colors In addition the background color can be removed showing through the original video It also has nine pulse width modulator outputs for controlling analog functions Similar to a standard 80C5 1 it has 28 digital I O pins two external inter rupts and two timer counters RAM and ROM spaces
6. A normal transmission will take 11 60 Hz cydes two for the start code four for the housecode and five for the function code In addition every command should be sent twice To turn on module A3 send housecode A function code 3 for unit 3 then housecode A function code On Taking into account the repeated transmissions and the required three cycles of silence between complete transmissions you end up with 2 x 2 X11 3 or50 cydes which is dose to a full second hope you don t have anything else for your processor to do while it s busy watching for zero crossings and turning the 120 kHz carrier on and off To make matters worse haven t even taken receiving The Computer Applications Journal into account where you must check for received data at every zero crossing using the TW523 have better things t do with my processing time There must be a better way A BETTER WAY PLIX PLM takes the burden of X 10 serial transmission and reception off the processor performing these functions as background tasks on its own Simply send the housecode function code and the number of times to repeat the command nor mally two and PLIX outputs the proper gating sequences to the PL5 13 or the TW523 If you re using the TW523 you can ask PLIX for the last X 10 transmission it heard The reply also indicates if the data is new was received after the last query If your system is battery backed you
7. On is the presence of al us pulse of the 120 kHz carrier and Off is its absence Thus one bit time equals one 60 Hz cycle Notice that each data bit is sent as three copies of the data bit plus three copies of the opposite logic state to allow simple error checking Noise occurs equally on each half of the power line s cycle whereas 120 kHz bursts must be present on only half the cycle to be considered legal This aspect is true for all house and func tion code data bits The start code uses a different format It is always the same two cycle sequence On On On On On On for the first cycle and On On On Off Off Off for the second Figure 1d Figure l a X 10 transmissions are synchronized b the AC power line zero crossings b A 1 data bit is represented by three 1 ms bursts of 120 kHz signal followed by silence during he next half cycle c A 0 data bit is just the opposite with the bursts occurring during he second half of the cycle d Every transmission begins with a unique start code which lasts two full AC cycles Issue 29 October November 1992 75 Listing 1 Sending and receiving X 10 commands can now be done even using interpreted BASIC 10 PORT1 09FH REM P1 0 4 as 1 0 P1 5 6 AS OUT P1 7 aS IN 20 v 0 GOSUB 1000 GOSUB 1000 GOSUB 1000 V 31 GOSUB 1000 SYNC 30 PRINT Hit W 40 G GET 50 IF G lt gt 57H AND G lt gt 77H AND G lt gt 52H AND G lt gt 72H THEN 40 REM to write to PLIX R to
8. SOFTWARE Software for this article is avail able from the Circuit Cellar BBS and on Software On Disk for this issue Please see the end of ConnecTime in this issue for downloading and ordering infor mation SOURCES Requests for literature on Signe tics Philips microcontrollers including the 80C5 1 Based 8 Bit Microcontroller Data Handbook may be directed to Sharon Baker at 408 991 3518 Contact Bill Houghton at 408 991 3560 with technical questions specific to the 87C054 and for information on the availability of a PC board and components for this project 410 Very Useful 411 Moderately Useful 412 Not Useful The Computer Applications Journal FAST COMPLETE ACCURATE DRAM TEST DIPs SIMMs SIPs 64K 256K 1M 4M AMSTAR 1 Ns RESOLUTION ACCESS SPEED VERIFICATION 80 ns thru 180 ns Std 249 0 45 ns thru 110 ns Fast 349 0 4MEG Option Add 89 0 AUTO LOOP Continuous Test 6 25 MBits sec ADAPTERS SIMM SIP ADAPTER 189 0 Tests 64K 256K 1 M amp 4M Devices 8 or 9 Bit versions NTX ADAPTER Tests 64 Pin Dual Edge LaserWriter Type SIMM s 149 0 SRS Se NNA 4 X ADAPTER 89 0 Tests 64K amp 256K By 4 Bit Devices AC ADAPTER Regulated 5V 1 Amp FREE RAMFACTS DRAM NEWSLETTER 1 800 RAMSTAR COMPUTERDOCTORS 9204 B Baltimore Boulevard College Park Maryland 20740 MADE IN U S A U S PATENT No 4 965 799 130 18 0
9. TS16 16 channel thermocouple expan sion board Supports J amp K types 298 Unparalleled choices for real world control Over 50 hardware and soft ware products for single and OEM users FREE 80 PAGE CATALOG Real Time Devices Inc State College PA USA Valara Tel 814 234 8087 FAX 814 234 5218 144 Issue X29 October November 1992 successive pulses of either type or if the data starts out with more than one long pulse A pair of zero counts marks the end of each block Your mileage will vary but typical data records weigh in at 70 to 150 bytes so you may be able to fit 200 IR signals into that RAM which is probably enough to get you into serious trouble Think of this collec tion as the ultimate universal controller with no k amp pad The original IR Master Controller included a character string With each IR signal but that unit was intended for stand alone operation and sported a keypad and LCD pand The MCIR Link is de signed for computer driven applica tions so felt that any strings should be stored in the system controller Each IR signal is identified by a record number between 1 and 999 that takes up only two bytes in the data record Although numbers may be cryptic they suffice for a simple row column key mapping layout For example call upper left key 11 the key to its right 12 the third key in the fourth row is 43 and so forth This system breaks down for some recent A V controller
10. Video LCD FDD HDD SSD Setup Real Time Clock Battery Back 8087 Socket 8088 10Mhz HDD 8 bit ine Port Solid State Disk Port Centronics LPT1 Port FDD 360k 1 44Mb Port Com2 Port Ti if VSVFIGVAOVLS e96SXV Newman Associates PO Box 22035 Lansing Mi 48909 5 17 394 2560 Pricing subject to Change Without N AXE96 Tradmark of Newman Associates i owners PCB ASIC Software Design 10V30 amp 25386SX SBCs Digital Analog I O V 29 32 Module s Solid State Disk Drive s Soon 486DX SBC Model 33486DX A The Computer Applications Journal Issue 29 October November 1882 77 78 MAGENATION VIDEO FRAME GRABBERS Simplicity Functionality Affordability Accuracy Cortex Real Time Capture Half Slot XT AT 512x484x8 Bit RS 170 CCIR Extemal Trigger Dual Video Input Opt XMS Mapped Low Power Options STD 80 or 32 Bus Extema Trigger Vidmux 4 4to 1 MUX Half Slot XAT Includes Software C Library amp Source Image Capture Utility Tiff Utilities Image Drive Ram Disk Emulation STARTER PAK Cortex Fak NEC TI23EX Camera With Lens 9 Video Monitor Frame Grabber Software amp Cables OEM PRICING AVAILABLE IMAGENATION CORP P O Box 84568 Vancouver WA 98684 PH FX 206 944 9 13 1 Issue 29 October November 1992 Connections shown for PLIX only generic 8052 circuitry removed for clarity optionel
11. for reg 1 reg lt MAXREG regt hue float reg 1 float MAXREG 1 if error setpal hue sat lite reg goto error handler draw_graphic0 key_wait _clearscreen _GCLEARSCREEN senessssesse 2 5 ae eee mesese seas s assesses Example 2 grayscale SSS hue 0 sat Q for reg 1 reg lt MAXREG reg lite float reg 1 float MAXREG 1 if error setpal hue sat lite reg goto error handler draw_graphic key_wait _clearscreen _GCLEARSCREEN saeeeescssses s SAn Example 3 blue to orange w increas sat and lite eT hue 0428 sat 6 0285 lite 3 0214 for reg 1 reg lt MAXREG regt hue 0428 sat 0285 lite 0214 if error setpal hue sat lite reg goto error handler draw_graphic key_wait _clearscreen _GCLEARSCREEN error handler _setvideomode DEFAULT if error printf setpal error d error 58 Issue 29 October November 1992 The Computer Applications Journal mm canon An inexpensive thin walled sacrificial plate or bumper is used to intercept the particle The shock wave stress caused by the collision is high enough to vaporize the particle so the debris carried downstream cannot harm the vehicle The palette definition begins with HUE setto blue a subjectively cool color and ends at orange a subjec tively hot color SATURATION and LIGHTNESS vary linearly at different
12. want to thank C J Dunford for the original code to DUMBTERM a simple terminal emulator Jim Schimpf works for an instrumen tation firm designing hardware and software for highway measuring instruments SOFTWARE Software for this article is avail able from the Circuit Calar BBS and on Software On Disk for this issue Please see the end of ConnecTime in this issue for downloading and ordering infor mation 407 Very Useful 408 Moderately Useful 409 Not Useful 8031 32 51 52 68HC11 Best Price Performance In Circuit Emulators ONLY HARDWARE Check out our complete line of DSP boards based on powerful floating point processors like the AT amp T DSP32c 25 MFlops and the Analog Devices ADSP 21020 75 MFlops Several analog interface modules are available DSP boards start at just 995 SOFTWARE We have everything you need to do DSP software development including C compilers assemblers source level debuggers algorithm development tools and many example programs Data can be transferred between the DSP board and host at up to 3 Mbytes sec with the host interface library source code included SOLUTIONS Call our friendly knowledgeable staff to discuss your applications and we ll show you how easy it is to take advantage of DSP technology 800 848 0436 RESEARCH SYSTEMS 400 East Pratt Street 8th Floor Baltimore e MD 21202 More Info 800 848 0436 FAX 410 783 7375 123
13. 359 e 12 bit 125 kHz A D Conversion e 16 Analog Input Channels e 3 Timers and 16 DIO Lines e Supports DMA amp Pacer Clock e AT Bus Version Available for AMPRO CPUs DM200 12 bit 40 kHz 8 channel analog input board 8254 timer and 16 digital VO lines 295 DM406 12 bit 100 kHz 16 channel analog I O board 2 D A outputs 8254 timer 16 digital I O lines Supports DMA and pacer clock 449 DM806 High current digital I O board 8254 timer opto 22 compatible 195 PC XT AT Boards AD2700 16 channel 12 bit 150 kHz analog input board Supports DMA pacer clock and programmable gain 8254 timer 16 digital I O lines 16 bit AT bus operation 525 TC48 Dual Am951 3 Timer Counters 24 digital I O lines 16 bit AT bus operation with expanded interrupts 398 DiO24 High current digital I O board 24 buffered DIO lines 8254 timer Com patible with opto 22 equipment 195 AD3110 Super fast 16 channel A D board 12 bit 200 kHz A D rate Burst mode operation On board FIFO memory Programmable gain Timers DIO lines Supports DMA and pacer clock Optional D A outputs 665 AD3710 Low cost version of AD31 10 with on board FIFO memory and 200 kHz burst mode operation 525 DA810 8 channel 12 bit D A Voltage or current loop output 8254 timer 24 digi tal VO lines 589 MR16 110 VAC mechanical relay expan sion board Computer control of 16 AC Et nn tess inet hig Pen E E 215 OP16 Optoisolated 16 channel digital input expansion board 225
14. NV 13760 TEL 607 748 5966 FAX 607 748 5968 Trademarks are property of respective holders See us at the Embedded Systems Conference Booth 305 Issue 29 October November 1992 15 Us 040 74 5145 D 079 SFH405 2 ae Q Q79 SFH3ES 3 D Figure 3a The buik of tie sensor amp made up of the LED phototransistor pairs One at a time each LED is Jit and its companion phototransistor is checked to find out if the light path is being blocked quickly the stem s position with a sensor The bend of the stem is referenced from the robot s grasp point to the bottom of the stem and the information is used when inserting the cutting into the plug Geranium cutting stems are frequently 5 10 mm in diameter with bends of 0 0 6 radians Before a stem has been inserted into the plug it generally extends below the robot s fingers 15 20 mm Thus the design criteria for the sensor included a 1 to 2 mm resolu tion a25 mm range in two dimen sions a mm maximum displacement between measured dimensions and a 100 ms maximum response time Object size was assumed to be within the range of 4 12 mm Also needed to keep component cost under 500 I pursued a small noncontact sensing method because of the infrequent need 16 Issue X29 October November 1992 for cleaning and the absence of any force applied to the plant stem which could affect the measurement or disturb the cutting within
15. SPI initialization LDAA 02 STAA PORTB LDAA 00000010 STAA DDRD LDAA 01001100 STAA SPCR LDAA SPSR LDAA SPDR e PBO is 74LS393 s CLR CLK and SCK f e Initiate scan LDAA STAA CLR JSR LDAA STAA or SPI 01 PORTB PORTB WAITI 02 PORTB PB1 is 0033 0047 Warm start Lower half of RAM U10 amp U20 pairs U9 amp U19 pairs U8 amp U18 pairs U7 amp Ul pairs U6 amp U16 pairs U5 amp U15 pairs U4 amp U14 pairs U3 amp U13 pairs U2 amp U12 pairs U1 amp U1l pairs Upper half of RAM Init stack pointer Zero B for counter Set X as counter Prepare CLK SCK hi and CLR lo SS SCK MOSIT MISO RxD In TxD Out SPI on as slave CPHA 1 CPOL 1 Clear any possible SPIF 74LS393 s First falling edge of SCK indicates start of xfer Scan initiated with 07 07 pair activation Wait a while D7 0Q7 s condition xfered thru MOSI continued The Computer Applications Journal RELAY INTERFACE PROVIDES SOFTWARE CONTROL OF RELAYS A AR 16 RELAY INTERFACE 89 Two 8 channel relay output ports are provided for control up to 16 relays expandable to 126 retays using EX 16 expansion cards Each relay output port connects to a relay card or terminal block A variety of relay cards and relays are stocked Call for more info RS 422 available distances to 4 000 feet PS 4 port selector may be used to control satellite AR 16 interfaces up to 18 384 relays RD 8 REED RELAY CARD 8
16. and see what the spectrum is You can flatten it by passing the signal through an inverse filter and l Il bet some simple HP or LP stages will do fine once you find the slope of the frequency response of the noise source suspect this wave shaping will be required for your digital shift register source too You don t need fancy gate arrays and stuff all you need is a big shift register and a few XOR gates to create the feedback See any college text on signals and noise or coding theory for the design They come under the title Maximal Length Sequence Genera tors or Pseudorandom Codes Msg 59320 From NELSON CHANE To RUSS REISS tried what you suggested a zener diode reverse biased using 15 V source and 1M resistor it generated noise just BCC72 BASIC 72 Computer Controller The BCC52ComputerController is Micromint s hottest selling standalone single board microcom i puter tts cost effective architecture needs only a power supply and terminal to become a complete de RR velopment or end use system programmable in BASIC or machine language The BCC52 uses Micromint s 80C52 BASIC CMOS microprocessor which contains a ROM resident 8K byte floating point BASIC 52 interpreter The BCC52 contains sockets for up to 48K bytes of RAM EPROM an intelligent 2764 128 EPROM programmer three parallel ports a serial terminal port with auto baud rate selection a serial printer port and is bus c
17. determine the Liner wa jor amd wisor axis aad artiga the appropriate values ex dmajedx or adie jody AF ahabeosebedy MEN BEGIR de fot dotan joc datatany abedan juabedx abedeiorabety diene pod ire divetandicy is mjor axis qajor axis distance me jorsminer axit det ed ress abs valees ef me jorcminor axis distance wajorvainor axis direction fies y ts mjor axis ahelen joabedy abadaisrehedx diron Jat ry divmtandiox os Fimatly the Breseshem elgerithe draus the line en Zeabadale abedam J POR inp TO dwaj STEP dirmay UF abadnreat isitiellze error eccum lator step in the es jor axis if x ts major axis Editor Configurable keystrokes and colors Memory resident text FASTI Block move copy delete read write Find amp replace e Auto Indent Compiler Structured programs DO UNTIL WHILE WEND BEGIN END No jine numbers Up to 20 character variable and fabel names Subroutine LOCAL variabies Five types of comments including multiline stripped during download Debugger UP fo 1000 BREAK PASSpoints Execution PROFILE Up to 40 WATCH variables Integer variables WATCHable as DEC HEX BIN An or partial array WATCH Terminal Editor file and compile buffer download to SBC Fife capture from SBC Host PC Requirements 512K One disk drive One serial port Mono C E V GA DOS 3 x 5 0 Individual versions are available for BASIC 52 BDT52 BASI
18. full 80x86 locator that outputs binary Intel OMF and hex formats You can debug with your Turbo debugger or use Datalight s remote debugger Either debugger will work through an available UART or ROM socket UARTs This comprehensive ROM development package is available for 1745 5 68th Ave NE Suite 304 Bothell WA 98011 U 121 The Computer Applications J our nal only 495 Call write or fax today for your free demo disk and full details about C_thru_ROM Free Demo Disk Call Today Toll Free 1 800 221 6630 SA 206 486 8086 fax 206 486 0253 Issue 29 October November 1992 3 3 Serial 1 O on the IBM PC As anyone who s tried to write serial support code for an IBM PC knows the BIOS routines just don t cut it when trying to keep up with multiple high speed ports Jim s package replaces the BIOS with capable routines 34 ISSUE 29 October November 1992 FEATURE ARTICLE Jim Schimpf onnecting various devices to an IBM PC or compat ible via the serial I O is very common and done so with
19. higher than the avalanche voltages A more expensive system replaces R1 and R2 with constant current diodes such as the 1N5297 Then you would not need more than a couple of volts above the avalanche voltage for the supplies Why the two diodes It turns out that the noise distribution from a single diode is skewed to one polarity When you generate both polarities and combine them as shown you get much improved noise quality This circuit produces a signal in the millivolt leve so you would need an op amp to amplify it to your 3V levels On the same amplifier you can do whatever band limiting and maybe amplitude limiting as well you may need Just add a capacitor over the feedback resistor for the bandwidth Add two 3 3 V zener diodes connected in series with opposite directions over that same feedback resistor to make about a 4V maximum output Then use a voltage divider or potentiometer for the final amplitude setting By the way what the commercial noise signal genera tor diodes contain is pretty much along this description so now you know k MICROCONTROLLERS e C Programmable Data Acquisition Control Test Excellent Support From 159 Qty 1 New Keyboard Display Modules Use our Little Giant and Tiny Giant miniature controllers to computerize your product plant or test department Features built in power supply digital I O to 48t lines serial I O RS232 RS485 A D converters to 20 bits s
20. output a synchronous GO output SG 30 Issue 29 October November 1992 Listing 1 continued ct5 ct4 ct3 i2 il i0 ct5 ct4 ct3 ct2 ctl ctd if ldth 0 if ct5 ct4 ct3 ct2 ctl cto il i0 ct2 ctl cto else if ct gt 0 if sg 1 ctl if ct 1 zr_ct 1 else zrct 0 else if go 0 i f zr_ct 1 ct ctl sg I put part definition putpart P22CV10Z tdr 123 4 5 6 7 load high i2 leave high bits alone go is low still put out sync go on first clock decrement counter on last count bring zr_ct high else zr_ct is leave count leave high bits alone load in to high ct let s jam count loop decrementing low to delay line zero then keep zrct 1 and sg atl 8 9 10 11 12 clk i0 il i2 ldtl 1dth g0 zr20 zr60 zr40 zr80 GND 13 14 15 16 17 18 19 20 21 22 23 24 zr zr_ct dlout ct0 ctl ct2 ct3 ct4 ct5 _ sg VCC end of definitions end of module The rising edge of SG is applied to the glitch monostable circuit formed by NAND gates U6a and U6b The output of this circuit goes low for about 8 ns on the rising edge of SG This pulse drives the base of Q4 When Q4 s base is pulled low it generates the very fast pulse at the BNC test cable output C6 fixes the high level output impedance of the TDR at a very low value Once Q4 is turned off the setting of latching relay Ki and the
21. suggested but the cost of the diode is 18 00 was hoping for a cheaper solution am considering the digital approach and will try to program a FPGA for the prototype The only problen is how to characterize the noise using Fourier transforms and plot the results using say MathCad Msg 59144 From RUSS REISS To NELSON CHANE Forget the noise diode It s probably speced for good performance into the microwave region but not for the REMOTE POWER CARD HARDWARE OR SOFTWARE REASONS PHONE TURN ON PC WITH PHONE SHARE VOICE MODEM LINE CONTROL AC APPLIANCES TIMER WAKEUP OR SHUTDOWN PC LATE NITE BACKUP MODEM CONTROL AC APPLIANCES 95 z DATA AQUISITION SERVO CTL AUDIO SHARP CUTOFF ANTI ALIAS FILTER 9 5 CREATE STEREO BLASTER VOC FILES VOICE MAIL MUSIC ALARMS CTL VOLT 8 BIT RESOLUTION 44KHZ SAMPLE RATE PLAYS MONO STEREO BLASTER FILES FUNCTIONS AS DIGITAL ATTENUATOR TOO ALL MVS CARDS INCLUDE ASM BASIC AND C SOURCE FOR PC OR SBC 8 BIT RESOLUTION22KHZ SAMPLE RATE MERAH 5 WEAR LIMITED WARRANTY 100 issue 29 October November 1992 The Computer Applications ournal low frequency audio that you need Try simply biasing a zener through a resistor and feeding that to an audio amp See what you hear For those low frequencies you could probably connect a simple ADC to your PC and do an FFT in software Maybe not in real time but who cares Just store some data process it
22. than or equal to 1 2 or subtracting 1 2 minl x5 x 0 delx from the hue if the hue is greater than return result 1 2 Next set pa 1 determines the maximum saturation level sat 0 Due to the double cone structure of the model sat 0 is a function of lightness float maxl float argl float arg2 At a lightness of 0 or 1 sat0 must be ad rasiri 0 and at a lightness of 1 2 it must be i 1 Ina fashion similar to the making of result argl the functions for RED GREEN and If arg gt argl BLUE you make use of two linear arene see functions and a MIN function to create the desired function return maximum of two floats i satO 2 lite return minimum of two floats minl 4 1lite 2 0 float minl float argl float arg2 The hue value is systematically float result passed to mag_blue mag_green and resike cardi mag_redto calculate blue green if arg2 lt argl and red values for the hue and the result arg2 euh value is also passed to calculate return result blul greni and red values for the hue complement euh Functions max 1 MAGNUM OPUS o o TRANSCEIVER CHIP CUSTO M ELECTRONIC ENGINEERING Micromint introduces its new Power Line Interface for X 10 PLIX is an18 pinASICchip that automatically handlesall the specialized SINGLE BOARD COMPUTERS X 10 timing and bit shuffling between a computer and a TW523 EPROM PROGRAMMERS i power line module
23. the trouble is there s no good way to tell when the signal is finished After examining all the signals available from the sack of remotes I decided the only reasonable method was to allow a prolonged period of silence to mark the end of a signal Ethernet Protocol Analyzer for LAN Manager and NetWare LANs Capture and decode live Ethernet traffic with any PC and a garden variety NIC for only 350 NetWare Core Protocol NCP NetWare Protocols Protocol Interprete Defined Protocols File Sharing Protocol SMB Monitor User File Accesses Watch Adaptive Windowing Tra psactions LAN Manager Protocols Protocol Suites Decoded by The Snooper Announcing the network manager s dream Full multilayer decoding of NetWare and LAN Manager protocols captured live from any PC Includes ready to run DOS based analyzer plus full source code including packet decoding modules in C and assembly The Snooper easily interfaces to most common NICs through standard packet drivers supplied in source and binary forms CALL TODAY FOR YOUR FREE DEMO DISK GENERAL ISOFTWARE PO Bax 2571 Redmond WA 98073 Copyright C 143 FESS Tel 206 391 4285 Fax 206 746 4655 The Protocol Experts 1992 General Software Inc General Software the GS logo and The Snooper are trademarks of General Software Inc The Computer Applications Journal Unfortunately several remotes insert delays up to 2
24. 1 6 x2 1 13 X38 25 4 S23 aN x5 5 16 union REGS regs int setpal float hue float sat float lite int reg ees Se convert HSL coordinates to RGB call s set_reg to load VGA hardware with palette data lt a SSS SS SSS SS SSS SSS SSS SSS void set_reg int reg intred int green int blue float mag_blue float mag_green float mag_red float float maxl float argl float arg2 float minl float argl float arg2 float ITENO 63 float red green blue float redil grenl blul euh sat0 Max VGA intensity if hue lt 5 hue compliment euh euh hue 5 else euh hue 5 sat 0 2 lite minl 4 lite 2 0 maxl sat0 0 max sat f lite sat0 minl sat0 1 mag_blue hue blue maxl blue 0 minl blue 1 mag _blue euh blul maxl blul 0 bl ul minl blul 1 blue ITENO lite blue 1 sat sat0O blul green mag_green hue green maxl green 0 green minl green 1 grenl mag_green euh grenl maxl grenl 0 grenl minl grenl 1 green ITENO lite green 1 sat satO e grenl d mag_red hue red maxl red 0 d minl red 1 red mag_red euh red maxl redl 0 red minl redl 1 red ITENO lite red 1 sat satO redl set_reg reg int red int green int blue REAL TIME MULTITASKING KERNEL 8086 88
25. 1099 The MNC 1150 ments vided Power requirements Fax 612 766 9365 offers complete PCMCIA The PCMCIA 2 0 card are less than 1 amp at 5 2 0 compatibility which socket is accessible through volts and up to 250 mA at 506 can support memory the card bracket so memory 12 volts when program cards up to 64 megabytes cards can be loaded and ming flash memory 2 4 EMBEDDED PC 4 PA E AAA Tei a sn Ag is g a A E A B Oar oa Microcontroller Microcomputer Megatel Wildcards provide PC functionality in a flexible small format Wildcard 88 Mulfi 10 Vid Mem e CPU clock to 10 MHz On board SCSI Host Adapter e 640Kb User memory e Replaces full PC motherboard supports up to 7 devices e Video Colour LCD controls e Co processor and BIOS socket e Floppy Controller 1 44M 1 2M CGA Hercules IBM Mono e DMA Bus DRAM Keyboard e 2 RS 232 Parallel RS 485 runs LCD Panels controllers multi protocol serial port For information on our representatives please All Wildcards are low power single 5 volt operation contact our head office at the number below 125 Wendell Ave Weston Ont M9N3K9 Fax 416 245 6505 416 245 3324 megatel Wildcard 88 and Megatel are trademark of Megatel Computer Corp Hercules is a trademark of Hercules Corp IBM is a trademark of IBM Corp 105 10 Issue 29 October November 1992 The Computer Applications Journal FEATURES ari DESIGN 12 Planting Geraniums by R
26. 161 86 Issue 29 October November 1992 The Computer Applications Joumal Single Board Computer 5 Singles 6 Features F68HC11 Max FORTH embedded in A8 amp 3 Parallel Ports 2 Serial Ports A D Watchdog 3 Memory Sockets 64K Addressing 8K RAM RS 232 Conversion Board size is 100x 100mm Approx 4 x4 CALL NOW NEW MICROS INC 1601 Chalk Hill Road Dallas Texas 75212 Tel 214 339 2204 162 The Middle Ground Negotiating a Keyboard Interface Much of the computer engineer s life is spent making tradeoffs between doing things in hardware and doing them in software John looks at several options available when designing a keyboard interface 88 Issue X29 October November 1992 PRACTICAL ALGORITHMS John Dybowski irmware the middle ground between hardware and software has the disposi tion at times to take on the attributes of both That this type of code has the capacity to perform tasks normally assigned to hardware may explain why its design often resembles a mecha nism more so than the workings usually associated with programming Firmware tricks can impersonate many hardware functions but as usual you must take into account the strengths and limitations of the methods you choose SOFT HARDWARE Generally speaking either using ICs dedicated to serving the desired purpose or emulating these functions in firmware can achieve the peripheral functions required
27. 8041 COP400 6801 8048 COP800 6805 8051 SUPER8 6809 8085 Z8 68HC11 8096 Z80 78C10 89700 MORE Cross l 6 Meta Assembler US 99 CN 119 XDASM Cross Disassembler US 249 CN 299 i a it _ High Performance Multimegabyte Disk Emulators E Both MS DOS products include support for ALL of the above processor families EPROM emulators and Forth compilers too E Request our catalog Credit cards are billed in Canadian dollars CNS Canadian residents please add 7 G S T NEW MODELS LOWER PRICES e Floppy Drive and multimegabyte emulators for ISA bus computers e 180K to 14 MB capacities e EPROM Flash or SRAM technologies e Autobooting Single or Dual disk emulation under PC or MS DOS List prices from 195 CURTIS INC 418 W Country Road D St Paul MN 55112 612 631 9512 FAX 612 631 9508 PC DOS is a trademark of IBM MS DOS is a trademark of Microscoft Universal Cross Assemblers P O Box 6158 Saint John NB Canada E2L 4R6 Voice Fax 506 847 0681 139 140 62 ISSUE 29 October November 1992 The Computer Applications Journal I designed this particular version of the circuit to work with the stan dard VGA D type 15 pin connector You can easily change the circuit to have it work with any other color video monitor standard as long as the Red Green Blue H Sync and V Sync signals can be identified These signals would be input into the core circuit in exactly the same manner The outputs of the
28. 80x86 88 80386 Z80 64 180 8080 85 68000 10 20 m Fast reliable operation E Compact and ROMable m PC peripheral support w DOS file access m C language support m Preemptive scheduler m Time slicing available Configuration Builder m Complete documentation m Intertask messages m Message exchanges m Dynamic operations task create delete task priorities memory allocation Event Manager Semaphore Manager List Manager insight Debugging Tool THE BEST Join over 1000 developers such as IBM Xerox Hewlett Packard Hayes HughesAircraftandNASA CHOOSE AMX The best low cost hi gh performance real time multitasking system available today No Royalties Source Code included Demo Disk and Manual only 85 US Call for prices for AMX 86 3000 US other processors Shipping handling extra IBM is a registered trademark of IBM Corp 280 is a trademark of Zilog Inc AMX AMX 86 InSight are trademarks of KADAK Products Ltd KADAK Products Lid 206 1847 West Broadway Vancouver B C Canada V6J 1Y5 A Telephone 604 734 2796 Fax 604 734 8114 134 The Computer Applications Journal Issue 29 October November 1992 55 magenta orange Figure 3 Taking a horizontal slice through the center of Figure 1 shows the euh or tie complement of the hue whichis necessary b determing saturation and mi n 1are used to keep returned values within range The RGB component
29. AC power fail modular phoneplug connects to PLS13 or TWS23 Figure 2 Adding PLIX lo a generic 8052 circuit is just a matter of connecting it to the processor s spare VO port come from the same port A minimum mapped into the available I O space of two output bits one input bit and Each of its two 8 bit ports is bit five bidirectional bits are needed from programmable any source If your processor does not However you choose to interface have any spare bits then use a periph with it the PLIX chip will atow your eral interface chip like the 6821 processor to keep up with all its Figure 3 The PLIX read and write cycles use very similar algorithms and rely on handshaking between the processor and the chip 1152 Tile Computer Applications J ournal 7 PLIX 10 9215 Micromint Photo 2 Due to the PLIX chip s low power consumption the demo board can be run off a 9 V battery important functions without having to twiddle its thumbs or bits during a time intensive X 10 serial transmis sion or reception If didn t know better I d have guessed it was X 10 who came up with this missing link Some companies just can t wait for the future they have to invent it PLIX DEMO BOARD I ve put together a little board that will allow you to experiment with this chip Photo 2 Even though PLIX only needs five external components and can be handwired easily immediate gratification can be a worthy attribute A modul
30. ASSOCIATES INC 11501 Chimney Rock Houston TX 77035 FAX 713 728 1049 Phone 800 525 4302 or 713 728 9688 118 The Computer Applications Journal Issue 29 October November 1992 See us atthe Embedded Systems Conference Booth 836 27 THE LCD The LCD display is a standard 4 line by 20 character module Figure 3 The menu program uses the top two lines to display measurement data and menu information and it uses the last two lines to display soft key data for the touch screen keyboard DAC A of U3 provides LCD contrast control VEE through op amp follower U4c The DAC voltage reference is provided by D4 a micropower 1 25volt bandgap refer ence The reference is buffered by op amp follower U4a and also provides a 2 5volt reference to the measurement drcuit through amplifier U4b TOUCH SCREEN LED CIRCUITRY An infrared light across the face of the display in a configuration where the operator s fingers interrupt it implements the touch screen display D1 D2 and D3 provide the IR light to phototransistors Q3 Q4 and Q5 respectively Transistors Q8 through Q10 drive the LEDs at 70 mA for brief periods of time P1 0 PLI and P1 2 provide the control signals through resistors R25 R26 and R27 The phototransistors operate at low gains using small collector loads of 1 k to minimize ambient light swamping further The transistors are AC coupled to transistor switches Q14 through Q15 by a differentiating n
31. AVERAGE MEMORY RECORD RELATIVE MODE DATA HOLD Ei DC AC VOLTMETERS DC Range 4oomv 4v 4ov 400V 1000V AC Range 400mV 4V 40V 400V 750V I E DC AC AMP METERS NEW DC AC Ranges 400uA 4mA 40mA 400mA 10A E om METER Range 400 4K 40K 400K 4M 40M 4000M Ohm M FREQUENCY COUNTER AUTORANGING Pange nager Hohi 400KHz 4MHz Trigger Low LOGIC PROBE gl AUDIBLE CONTINUITY TESTER ml CAPACITANCE TESTER RMA 4nF 40nF 4001F 4uF 40uF ai dBm TESTER OFFER Range 25 7 dam to59 7dBm gl INDUCTANCE TESTER Range 40mH 400mH 4H 40H E 10 MEGA OHM IMPEDANCE 10A HIGH ENERGY FUSE PROTECTION AUTO SLEEP amp AUTO POWER OFF WATER amp DUST RESISTANT MODEL 94 COMES COMPLETE WITH TEST LEADS YELLOW HOLSTER TILT STAND BATTERY amp FUSE Stock No 990111 ue 1 9 ia 2 YEAR WARRANTY KELVIN 10 HUB DRIVE MELVILLE NY 11747 800 6459212 516 756 1 750 516 756 1 763 FAx 165 90 Issue 29 October November 1992 detected and if so if the key has already been debounced This opera tion consists of first checking KEY_ H IT Only single key hits are allowed so the routine terminates if K EY_HIT is anything other than one If KEY _H IT is one then the global variable LAST KEY is consulted If KEY NUMBER isequalto LAST KEY the Boolean global DEBOUNCED is checked If LAST KEY equals KEY_ NUMBER and DEBOUNCED iszero this key is being seen for the second successive pass has not yet been re
32. JRC2244 accepts a switching control signal from the 87C054 and switches its output between the original video input and the OSD video signal The video switch also has an internal 75 ohm line driver in its output stage The JRC2244 has a moderate input impedance of about 1 5k ohms allowing 10 pF coupling capacitors to be used The output coupling capacitor is large because this signal can be used to drive 75 ohm loads RGB ENCODING The LM 1886 U13 and the LM 1889 U14 encode the RGB data from the 87C054 into baseband video The LM 1886 has three DACs one for each color Each of these DACs has 3 bit inputs but because the 87C054 data is digital the inputs to the LM 1886 DACs are tied together yield ing an output for each DAC that is 46 issue 29 October November 1992 either full scale or zero The outputs of the three DACs are internally summed to produce the luminance R Y and B Y amplitudes The LM1889 accepts the regenerated chroma subcarrier modu lates the R Y and B Y signals and produces baseband video on pin 13 Transistor Q5 is used as a buffer amplifier with voltage dividers R49 and R50 producing proper levas for the video switch Note that the LM 1889 accepts an external subcarrier signal at the junction of R46 and C52 but this subcarrier undergoes a phase shift caused by the resistor and capaci tor networks associated with pins 1 and 18 of the LM1889 This phase shift will need to be considered when
33. M AbdelRahman Artificial for two dimensional position Intelligence expands sensor measurement of small objects applications Electrical Con Transactions of the ASAE 1992 struction amp Maintenance December 1991 5 S Ciarcia Why microcontrol lers BYTE August 1988 6 S Ciarcia B Brown Using the Motorola MC68HC11 Circuit Cellar INK ssue 18 December January 1991 7 M68HC11 Reference Manual Motorola Inc 1989 8 Optoelectronics Data Book Siemens Components O ptoelec Brian Farmer was formerly an Elec tronics Engineer with the University of Georgia Experiment Station and occasionally does consulting through Power Tech Inc He is now a full time My thanks to the clear thinking and wise supervision of Dr Ward Simonton by the robot before attempting inser tion into the plug Also it has the capability to abort a particular cutting cyde if no object is detected k assistantship TW523 Power Line Interface Developers Kit Interface Your Computer To Transmit And Receive X 10 Codes Over Your AC Power Line Two Way Communication Real Time Environment Control Wy Kit Includes TW523 Cable Interface Connector S P Documentation Source Code Su plied in C Pascal BASIC or Run Time Disks 5 25in amp 3 5in Format Baran Harper Group Inc Voice 416 294 6473 BBS 416 471 6776 Fax 416 471 3730 student in the University of Arkansas s Electrical E
34. Not Useful gt Project Parts lt IR3C07 laser diode controller IS1 U60 38 kHZzIR receiver LD273 dual IR LED bright IRLEDs 10 TLN1 10 1 LD273 Excellent IR filter opaque MC1 45030 IR encoder decoder DS1231 power monitor DS2400 silicon serial ID 2 pc MT8809 8x8 analog crosspoint MAX134 digital multimeter MAX252 optoisolated RS 232 MAX691 power supervisor 16C55 logic analyzer w DRAM IL300 linear optoisolator Lots more call write FAX for catalog UPS Ground 2nd day next day 6 8 16 to 48 US states COD add 4 Check or MO only no credit cards or POs CT residents add 6 sales tax Quantity discounts Data sheets included Fure Unobtainium gt Your unusual part5 source 4 89 Burbank Road Tolland CT 06084 2416 FAX voice 203 870 9304 Rae A Oa INK Let Me Tell You About Y ourself ive years ago when we started the Computer Applications Journal had a specific idea and direction in mind Much like the projects that had been presenting for 10 years in BYTE the magazine envisioned would appeal to a select group of technically motivated individuals who appreciated the fundamental application of a computer without speculating that it involved some mystical influence Five years is a long time however and without constant reassessment it s easy to vary from the defined course or indeed follow one too closely In the beginning when had no other information merely defined the editorial focus of CAJ to be w
35. address This section of code gets the pointer to the menu stack This section of code uses the current menu table to obtain A s the submenu table address B A It then loads that address A A DPTR into DPTR ACC A MDATA 32 Issue 29 October November 1992 The Computer Applications Journal Listing 2 contived MOV A B INC A MOVC A A DPTR MOV DPL A POP DPH Once anewtable has been to be repainted SETB DISPFLAG Set SETB TTLEFLAG Set MOV OPPTR 0H INC DPTR INC DPTR POP OH POP OFOH POP ACC RET display with the currently selected menu Listing 2 is an excerpt from the TDR s code A small collection of functions that operate on 32 bit variables performs all math on the TDR The TDR needed only an addition subtrac tion multiplication and division function loaded print option print title Reset pointer to top of menu Point to the first item in the table schedule the screen flag flag THE COMPLEAT TDR The instrument we ve described works in its most basic form but we think there is plenty of room for improvement before any reasonable production could be considered It would be fun to extend the number of cable types supported and maybe even add optical cable support The biggest leap in functionality would be to make the TDR or something like it a more integrated part of a network It could be a device that resides semipassively on the
36. all 8051 variants has full BXC51 295 ae 508 369 9556 point FAX 508 369 9549 integer byte amp bit E i Binan Technoloav Inc P O Box 541 Carlisle MA 01741 169 The Computer Applications Journal Issue 29 October November 1992 93 CONNEC E sn ren oman The Circuit Cellar BBS 300 1200 2400 bps 24 hours 7 days a week 203 871 1988 Four incoming lines Vernon Connecticut We re going to cover a few new topics in this installment of ConnecTime The first thread deals with sensing engine knock in a racing motorcycle Next we move into high speed data collection Finally we ll make some noise white noise that is Msg 58203 From KELLY DRESSER To ALL USERS Has anyone out there worked with pressure sensing in internal combustion engines What I m looking for is essentially a poor man s Kistler don t need absolute accuracy as much as low cost and ease of use want to sense the pressure peak and have enough frequency re sponse to detect uncontrolled combustion knock in a single cylinder four stroke 600cc racing motorcycle engine It s air cooled which adds even more of a heat problem to an already messy sensing environment Has anyone used any unconventional or clever techniques to measure or infer the pressure profile with respect to crank angle Msg 58227 From MIKE RAPP To KELLY DRESSER If you _really_ need to get cylinder pressure data then think there are no cheap and dirty soluti
37. and say What s the best way to figure out what did wrong After a little head scratching Noise Level dBm Figure 2 One of the Z8S180 s new features is he ability to reduce drive current on some key control lines to heaven forbid should get out sche reduce radiated EMI With he feature tumed on a 20 MHz Z8 180is quieter than the original 10 MHz Z80180 that matics and scope this early on began to wonder about some of the 180 s on chip control bits Hadn t the CPU gone through some revisions to better adapt the bus timing to Zilog peripheral chips seem to remember an I O doesn t have he feature compatibility bit somewhere thought I d better take a quick look at the register definitions also thought about the rest of the bits was setting in register 3FH Maybe they did something Hey register 3FH doesn t have any clock divide bit The Disk is DEAD DON T SELL YO CUSTOMERS A PROBLEM Dust moisture and vibration kill rotating disks every day Instant Access No Motion solid state memories offer extremely high reliability light speed access and the ultimate in data integrity Instant Access is available in FLASH EEPROM and NVRAM and is programmable in DOS or WINDOWS Rely on Instant Access the demonstrably superior No Motion Memory Instant is the Solution Access 1000 times faster an 100 times more reliable Ideal for sto
38. and work smart Being wasteful is foolish there is no virtue in drudgery Q John Dybowski has been involved in the design and manufacture of hardware and software for industrial data collection and communications equipment 428 Very Useful 429 Moderately Useful 430 Not Useful a Memory mapped variables a In line assembly language option Affordable state of the art in circuit emulation for Z80 family processors Increase your productivity with features like e Symbolic and C Source Level Debugging e Pull Down Menus and Command Line interface e Complete Context Sensitive Help e Real Time Emulation up to 12 MHz e Serial Interface works on any PC even on laptops 280 2180 Z84C13 284015 HD64180 HD647180 TMP84C015 Satisfaction guaranteed with a risk free 15 day trial Rentals also available Call or write today for more information Control Resources 19042 San Jose Unit S P O Box 8694 Rowland Heights CA 91748 818 912 5722 Voice 818 854 1439 Fax 168 only 8051 52 BASIC compiler that is 100 BASIC 52 Compile time switch to select 805 1 803 1 or 8052 8032 CPUs a Compatible with any RAM or ROM memory mapping m Runs up to 50 times faster than the MCS BASIC 52 interpreter m Includes Binary Technology s SXA51_ cross assembler amp hex file manip util Em Extensive documentation m Tutorial included Compatible m Runs on IBM PC XT or and compatibile E Compatible with
39. are saved in ASCII files Programs that read these files can use the source code given in this article to set their own palettes MYPAL is available in DOS and Windows formats A nominal fee to cover shipping and handling will be requested Eclectic Systems 8 106 St David Court Springfield VA 22 153 413 Very Useful from periwinkle to thistle is both easy and fun Q it An add on board with recreated 68HC705K1 interrupt logic and 64 bit PEPROM in hardware converts the 68HC05P8 EVS into a complete 68HC05 K family real time ICE not a simulator Comes with user friendly PC driver software 16 pin emulator cable and plug Demo disk 5 00 Part number EVSK1 ICE Price 68 05 PC based user friendly real time 68HC11 ICE New 64K memory module supports different probes Active probe reduces propagation delay to target system Full speed up to 20 MHz single chip and expanded modes On board 64K emulation RAM maps to 4K blocks 64K real time hardware breakpoints Breaks on address address range and memory RD WR Full symbolic debugging Supports all A D E and F1 parts 40 pin logic analyzer connector 64K memory module 295 00 Probe with PC driver 450 00 44 PLCC to 40 DIP adapter 55 00 Suite 238 uite 52 PLCC to 48 DIP adapter 55 00 360 W Schick Road Bloomingdale IL 60108 708 894 1440 FRANCE distributor LS LT CO Tel 33 6185 57 67 WICE Z8 emulator New Mexico Press Albuquer que
40. at 12 VDC A built in timer assures motor speed consistency regardless of computer speed The Quickstep requires only one 8 bit slot and features programmable address selection to allow coexist ence with other cards that may otherwise cause address conflicts The software is very easy to incorporate into any application The included subroutine libraries support C and QuickBasic and feature linear and circular interpolation ramping keyboard interactive jog and electronic gearing The QuickStep motor controller sells for 389 for a three axes system One axis and two axes systems are available for less MicroKinetics Corp 1220 Kennestone Cir Ste J Marietta GA 30066 404 422 7845 Fax 404 422 7854 504 NAATO NEWS HARD DRIVE ENCYCLOPEDIA The Micro House Encyclopedia of Hard Drives is now available from Jensen Tools This unique three volume support tool provides comprehensive technical help for the installation and upgrade or maintenance of multivendor hard drives It contains information on hundreds of drives from Alps to Zebec induding many The Micro House Encyclopedia of Hard Drives Part 764B880 is featured in Jensen s Catalog Supple ment D and costs 150 Jensen Tools Inc 7815 S 46th St Phoenix AZ 86044 602 968 6241 discontinued makes and models The information is loose leaf bound in three ring binders to make page replacement and update easy and comes w
41. circuit could then be connected to the appropriate pins of the connec tor for that color monitor standard Note the signals are identified as IDO ID1 and ID2 The VGA monitor provides these signals to the video board for input They identify a monitor s type to the VGA board and the video board uses this information during its power up automatic mode setting operation In order for this operation to finish correctly and without conflicts only one monitor should provide these signals Therefore if you use multiple cores only one port should pass these signals to the VGA board The one port that has these signals connected 8051 EMBEDDED CONTROLLERS WITH ALL THE EXTRAS We offer a full line of low cost 80C32 embedded controllers and software tools They are ideal for developing products test fixtures and prototypes Features include Low power CMOS design RS 232 and RS 485 ports Up to 60K of code space Up to 60K of data space 5to 15 volt operation Small form factor 3 5 6 5 System diskette includes application notes and an assembler Start at 100 Available Options Real Time Clock Watch Dog Timer through it will be named the master monitor port because the monitor connected to it will be used to set the power up mode of the video card Connect the lowest performing monitor to the master monitor port to ensure all monitors connected to the other ports are capable of operating If
42. display implement special built in display functions such as color bars and to read and write OSD registers directly giving full control of the OSD to the HCS II CONCLUSIONS Developing this application was interesting and enjoyable It also presented some challenges The 87C054 proved well suited to this application in large part because of the 80C51 core and that the OSD is independent of the CPU Once charac ters have been written to the OSD you can forget the OSD until you want to change the display and the CPU is free to pursue other tasks The on screen display and the microcontroller operations are prima rily digital functions The question of how to combine this technology with an analog video signal can be perplex ing to most system designers whose professional experiences have been mostly digital circuits One of the most perplexing issues during this project was how to recreate the chroma subcarrier knew that every color TV set had to perform this function but finding out solutions took some searching before discov ered the CA3 126 I m hopeful you can profit from my experiences on this project O My thanks to Herb Kniess and George Ellis of Signetics for their help Thanks also to Greg Goodhue from Signetics who wrote the software based UART code for the 87C 751 that modified for this project Bill Houghton is an Applications Engineer at Signetics specializing in 80C51 based microcontrollers
43. effect the intensity and saturation variables are set to 1 2 The for loop divides the hue into equal intervals between 0 and 1 Example 2 creates a gray scale SATURATION is set to 0 outside the for loop LIGHTNESS is graded between 0 black and 1 bright white within the for loop Any value of hue can be used since SATURATION is 0 Example 3 strives to define a palette that will elucidate the physics of a scientific calculation In this case the physics is the plastic strain in a simulation of an aluminum pellet striking an aluminum satellite bumper shield at 6 5 kilometers per second ZeuS hydrodynamic computer code 3 performed the simulation Whipple 4 first proposed using satellite bumper shields for protecting spacecraft Orbital velocities of micrometeorites or relics of yester day s space missions vary from a few to tens of kilometers per second At those velocities even gram sized particles can pack the wallop of a 30 Listing 4 Several examples serve to show the compactness of wde needed to define an array of colors and the versatility of the HLS model include lt graph h gt mai n0 define MAXREG 15 int setpal float hue float sat float lite int reg void draw_graphicO void key_wait int reg error Q float hue sat lite _Setvideomode _VRESI6COLOR VGA 16 color S22m R Example 1 blue to blue with pastels k lite 5 sat 5
44. enough for you What you really wanted was to send IR commands from the HCS to your TV VCR CD amp widgets The IR Link seemed to have all the essential hardware so it ought to be a simple matter of software Right The MCIR Link module is our response to your requests In addition to all the IR Link functions it can record and play back the IR signals sent by most hand held remote control units The initial training must be done manually you need a finger to push the remote s buttons but transmission is entirely automatic and can be handled by the Supervisory Controller s XPRESS program The MCIR Link board s 32K byte RAM has enough room for several hundred remote control signals so you can control nearly anything Figure 1 presents the new MCIR Link commands the complete IR Link set is given in Infrared Home Control Gateway in issue 26 You simply teach the MCIR Link new IR signals using the T command and send them with the SM command The H com mands allow you to dump and restore the IR data so you can save your work on disk and program itinto EPROM As with all the other Links you will need a PC with a terminal emulator program to drive the MCIR Link in the interactive mode Also like previous modules this board and firmware can be used in applications that have nothing to do with HCS II The Links use a straightforward ASCII command set over standard RS 232 or RS 485 wiring therefore you can d
45. everything from a manufacturer s microprocessor development board to your latest widget The serial interface is extremely convenient requiring only a few wires and usually stretching far enough to make remote control mean something The PC has the hardware to make this task easy but the standard BIOS for IBM and clone PCs does not support anything but polling type I O which means you are guaranteed to drop characters unless you use low data rates A large number of software I O libraries are available that can make the PC serial I O live up to its hard ware These libraries are all very good but if you are like me and have more time than money the simple full duplex serial I O package describe here is all you need to make your project hum The code for SERCOM is written in Microsoft Quick C and can be easily added to your program It can open multiple serial channels your hard ware limits the number and each channe supports full duplex with ring buffers on both input and output Various status checkers are present so your program can monitor the arrival of each character or only be notified when a complete line is received This way even a program running on a slow 8088 can monitor two 9600 bps channels Also included is a sample terminal emulator designed to talk to a popular microprocessor development board The Computer Applications J ournal THE SERCOM SERIAL I O PACKAGE ERCOM has ring buffers on
46. incoming video signal and the on screw characters under control of the 87C054 MCU number or burst of cycles of the color subcarrier hence the term color burst are transmitted on the back porch of the horizontal sync pulse In most NTSC systems this chroma subcarrier has a frequency of approxi mately 3 58 MHz A typical line of color NTSC video is shown in Figure 2 In order to convert the character data from the OSD into NTSC you will need to sum the data into R Y and B Y components Then you will need to modulate these components with a chroma subcarrier at 0 for B Y and 90 for R Y One more item to consider If you have an output video signal composed of a video source with characters overlaid onto it the chroma subcarrier reference i e color burst present on the output video signal is the color burst provided in the original input video In order for the receiver monitor to interpret the color of the OSD characters correctly the chroma subcarrier used to modulated the OSD s R Y and B Y components must have exactly the same frequency and 4 z i MultiTask ee and GOFAST Math Speed Time to Market Ze your application with peak performance using tested code and expert support Control real time scheduling with MultiTask source code executives or ROM able re entrant GOFAST floating point Replace 80x87 MATH COPROCESSORS Drop in IEEE SOURCE LIBRARIES Link and Go with C compi
47. integer math package We used the menu system to make the TDR easy to use and to permit some reasonable level of expansion and improvement The integer math package affords some computational capability but keeps code size within the constraints of the 4K maximum of 87C51 The goal of the menu system is to provide a b treelike structure through which menus and submenus can be called for and returned to in a straight forward fashion We wanted to add move and remove menus and pro Listing 2 The touchscreen allows easy changes and additions fo the menuing system Main Menu Strings amp Prompts MAINMNU DB TESTCBL DB TESTTYP DB CBLTYP DB SHW_PAR DB ADJ DSP DB Adjust tee MAIN MENU OH Test Cable Set Test Type Set Cable Type Show Setup Display OH 0H OH 0H 0H data structure for main menu MMENU w stest cable DW TESTCBL DW RUN DW OH stest type DW TESTTYP DW NXTMNU DW TTMENU cable type DW CBLTYP DW NXTMNU DW CMENU show parameters DW SHW_PAR DW SETUP Ow OH sadjust display DW ADJ DSP MAI NMNU PTR to main menu string PTR to function title PTR to function routine No data this time PTR to PTR to PTR to submenu title Nextmenu program submenu data structure PTR to PTR to PTR to submenu title Nextmenu program submenu data structure PTR to submenu title PTR to Nextmenu program PTR to submenu data structure PT
48. knows improper termination and bad cables are common culprits Let this time domain reflectometer make your life a little bit easier Issue 29 October November 1992 few years ago a friend of mine needed a portable network cable tester He does LAN management and found that cable problems were the cause of a very large number of network insta bilities wasn t surprised having also managed several large networks at one point in my life had grown weary of having a system fail whenever some one decided to rearrange the office and inadvertently disconnected the network while moving a computer Certainly no replacement exists for building networks with some leva of fault tolerance but doing so is not always physically possible or economi cally viable The type of cable tester my friend suggested was not going to solve network errors originating from the designer office worker anyway Nevertheless my friend reasoned that if a truly fault tolerant network wasn t possible providing the means to quickly locate the cable fault was the next best thing He proposed build a network cable tester a Time Domain Reflectometer TDR Our portable TDR is based on the Intel 87C51 microcontroller We designed it primarily to measure the The Computer Applications Joumal length and termination impedance of coaxial cables commonly used in computer networks such as Ethernet Arcnet and so forth The TDR
49. libraries edit your ounparts directly on the drawing Handy for 2D drawing too Drives al window printer devices including POSTSCRIPT end color printers LoadsISISSUPERSKETCHand DESIGNER files directly ISIS ILLUSTRATOR ony 349 ag eae Inc O B0X 7 West Hill Ontario Canada MI E 4Y9 416 399 0943 Here is a drcuit that is useful for true white noise generation R1 AD1 AD2 R2 A a i a ci c2 R3 R4 Output AD1 amp 2 are preferably matched avalanche diodes zener diodes with over 5 1 V nominal voltage The higher nominal voltage you select the more noise ampli tude you get but also the narrower the bandwidth Staying around 5 1V you may get flat response to over 20 MHz depending on layout induced capacitances and the buffer input capacitance after R3 and R4 Of course you might choose to have two buffers before summing the two signals The values of R1 and R2 should be selected so that the diode currents are above the knee but not too much Probably somewhere in the 0 2 to1 0 mA range is fine The EPROM PROGRAMMERS 5750 Completely stand alone orPC driven Programs E E PROMs 1 Megabit of DRAM User upgradable to 32 Megabit 3 6 ZIF Sockets AS 232 Parallel lo and Out 32Kinternal Flash EEPROM for easy ilmware upgrades Quick Pulse Algorithm 27256 in 5 sec 1 Megabit in 17 sec 2 year warrani e Madein the US A Technical support by phone Complete manual and
50. may want to use PLIX s AC power fail output pm as a system input that indicates power line status A simple bit programmable bidirectional 8 bit port is all that is necessary to carry on a conversation with PLIX Two output bits control chip select and data direction RD WR one input bit reflects PLIX s status RDY BUSY and five bidirec tional lines transfer data Only five external components are necessary two resistors pull ups for the PL5 13 or TW523 two capacitors and a crystal The 18 pin DIP package requires less than 2 mA at 5 volts to operate Slightly more is needed when supplying the gating pulse to the optocoupler of the PL5 13 or TW523 during X 10 transmissions USING PLIX Figure 2 shows the PLIX chip connected to Port1 of an 8031 8052 processor Listing 1 shows a sample program that excercises the chip The code is straightforward and easy to understand because the port is bit addressable and accessible directly through BASIC If you re not using an 8052 Figure 3 shows a pair of flowcharts that describe the proper algorithms to use to write to and read from PLIX Getting in sync with the PLIX chip after reset and terminating a function prior to finishing are both good practices Simply send the PLIX three or more 0 data bytes followed by a3 1 The 0 values are illegal repeat commands and PLIX will hold in the repeat state If a 31 is received which is also an illegal repeat value the
51. microwave sensors see up to 150 feet through foam buildup glass and non metallic substances and are unaffected by environmental conditions These proven low cost solutions are available off the shelf or custom made for OEM use Call For Your Free Selection Guide 1 800 289 261 1 AM Sensors Inc 26 Keewaydin Drive Salem NH 03079 2839 Phone 603 898 I 543 Fax 603 898 1 638 72 ISSUE 20 October November 1992 quency You should also avoid using edges immediately after the timing gaps such as edge 2 in Figure 5 because the firmware was busy storing the previous byte and could not sample the input bit That transition may have actually occurred any time in the previous two sample times so predse timing isn t possible Unmodulated IR signals will appear to be straight lines low while the LED is ON and high for the OFF times Renember that the MCIR Link hardware and firmware can t handle those signals ON THE AIR The MCIR Link EPROM hex file MCIRB HEX is available on the Circuit Calar BBS for your noncom mercial use The source code is not available but it may be licensed from Circuit Cellar Inc not INK Contact them for details You may also download the complete RSAMPLE C source code and RSAMPLE HEX for your IR Link board to check your remotes for GET YOURS of the top 146 The Computer Applications Journal TODAY MCIR Link compatibility You will need the current versi
52. not occur by the conversion of electrical energy to heat energy as you might expect in resistive circuits In fact as have shown although Z is real P represents the magnitude of power passing any point on the transmission line during a given instant As long as each subsequent section of the transmission line has the impedance Z the waveform continues to travel down the transmis sion line undisturbed each section passes energy to subsequent sections The specific V2 Z changes upon reaching a section of cable or termina tion resistance that does not have the equivalent characteristic impedance Some portion of the power must be either returned or reflected because a diminished or increased magnitude of power is transmitted to the new load The 0 or 180 phase is a consequence of the increase or decrease in power transmitted at that point Real life transmission lines do not behave strictly this way At some point the cable length becomes significant because the assumption that cables are lossless is not valid In real cables both the conductor and the LEDL 4x 28 LCD Display BUZZER UCC DAC A DISPLAY RS DISPLAY E DO Figure 3 User input to the T is through a touch screen interface Three pars of LEDs and phototransistors detecta finger pointing at one of three choices displayed on the LCD display dielectrics have resistance This resistance not only affects the trans mitted wave amplit
53. of three wait states This stretches memory access to six clocks three is the minimum making the bus cyde 300 ns at 20 MHz Past experience told me that the access time required of the memory is about half the bus cycle or 150 ns which isn t a problem even for EPROM and certainly not for the SRAM Before heading off also wrote a simple test program to allow me to exercise the board with different wait state settings HUMAN ERROR Over at Zilog 180 board and test program in hand sat through a nice presentation describing the S180 though was chomping at the bit to head for the lab The helpful folks at Zilog pointed out some of the other key enhance ments One particularly unique feature is the Z8S180 s ability to reduce the drive programmably to all of its outputs or just to selected subsets The effect is to slow the edge rates thereby reducing radiated ElectroMagnetic Interference EMI significantly Figure 2 Besides keeping the FCC at bay this feature is especially helpful in wireless communications applications Surprisingly the S180 consumes little more power than the 180 even at full speed operation Normally CMOS power consumption is almost linear with the clock rate If the clock rate is doubled the power consumption should increase significantly H ow ever the S 180 consumes only 40 mA at 20 MHz compared to 36 mA at 10 MHz for the 180 One simple explana tion for this dif
54. parallel combination of R8 R9 and R3 1 determine the impedance The Computer Applications Journal the line sees This impedance is either 50 ohms or 75 ohms depending on the setting of K1 Note that K1 is a permanent magnet latching relay briefly pulsed by the microprocessor to change state through Q1 and Q2 although it draws no quiescent power The output connector is also capacitively coupled to U5 an LT1016 a very high speed comparator This device has a propagation delay of 7 ns and specifically operates on a single supply The comparator does have a limited common mode range of 1 25 3 5 volts when run on 5 volts To push the signal into this range the positive input is biased to 2 5 volts by doubling the voltage reference which brings it to the approximate center of the common mode range DAC Band amplifier U4d provide the negative input to the comparator The range of this input is 0 3 95 volts The DAC resolution is about 16 mV for measuring the height of the returned waveform The comparator has complemen tary outputs connected to the clock inputs of U7a and U7b Two flip flops eliminate the pulse width uncertainty associated with measuring negative returning pulses The microprocessor samples the flip flops outputs at the end of a trial measurement at P2 0 and P2 1 The PAL s LDTL input clears the flip flops at the beginning of a trial measurement They are set after the return of a pulse if the
55. parasitic capacitance of the coupling cap 1 pF swamped the noise and gave about a 20 MHz oscillation Tried different caps from 10 pF to 10 uF and no go How can AC couple the zener diode to the op amp Am I using the wrong op amp The configuration of the op amp is ve input has a 200k resistor to ground a 2M feedback resistor from ve input to output in parallel with a 200 pF cap the ve input has a 150k resistor to ground and is also where the coupling cap from the zener circuit is connected Msg 59363 From RUSS REISS To NELSON CHANE Try coupling the noise source into the negative input Sounds more like breadboard prototype problens wherein the high positive gain is causing the oscillation As an inverting stage it might be much more stable The noise won t care that it s upside down Msg 59371 From PELLERVO KASKINEN To NELSON CHANE SCHEMATIC DRAWING FOR WINDOWS ISIS ILLUSTRATOR combines the high functionality of the ISIS product line with the graphics capabilities of Windows 3 to give you unparalled control of the appearance of your drawings When the drawing is complete you can output to any printer supported by Windows or the drawing can be read into most Windows DTP and WP programs e RUN under windows 3 x a Full control of drawing appearance includin line widths fill styles fonts colors and mori curved of angular wire comers Fully automatic annotator Comes complete with component
56. previous commands are flushed and chip resets DESIGNING WITH PLIX PLIX does not have the speed required to interface directly as an I O bus peripheral so it must interface through port bits As you have seen interfacing to the 8052 s port 1 is easy because each bit is individually programmable for input or output However all control does not have to Position and or Velocity Motion Con K lt _ CAU CONTANTO NTAN Lal DCX VME A a ennenen to 8 Axis Motor Motion Controllers e Intelligent state of the art DSP Multifunction Programmable Controllers can be configured in minutes using off the shelf components Model DCX motherboard contains _intelligence memory firmware and 6 or 8 sockets for plug in DCX Control Modules 1 to 8 plug in DC Servo Stepper or Special Purpose Control Modules can be mixed matched on same DCX board e Install in ISA bus PC XT AT or VME bus 6U or use stand alone with RS232 or IEEE 488 GPIB communications interface Modules 436 Analog I O 8 or 12 bit 16 144 Digital I O TTL plug compatible with Opto22 e High level interface libraries in C BASIC and Turbo Pascal with examples and source code and many Utilities CAD CAM G Code Servo Tuning etc included a Precision MicroContro Oo N C 0 R P O R A T J K7 8122 Engineer Road San Diego CA 92111 Tel 619 565 1500 FAX 619 565 1511 HEA SuperSet XT BIOS 8SXT
57. reflectometer works Transmission lines result from the interaction of wire sections that make up any circuit In most cases the interaction between the wire in the signal and return paths is insignificant relative to the effect of the physical components that form the system However in the case of network cabling the distributed reactance both inductive and capacitive is substantial with respect to the data rates involved Figure 1 and some differential calculus help show how these reactive de ments sum In an infinitesimally small element of the transmission line dz voltage and current are defined by V V dV dV Ldz 2 and dl Cdz 25 where L is the series inductance and C is the parallel capacitance of the cable conductors measured in inductance and capacitance per unit foot If assume a lossless transmission line can combine the above equations to form a pair of linear differential equations representing the variation of voltage and current in the conductors at position z These equations are 3 3 52 F vv 2 L31 2 al 1c FV sr BCH SOR 1S They have a solution of V F z vt F z vt where v and z must be 1 v VLC z and v play very important roles in the TDR s capability to make its measurements z is the characteristic impedance of the cable and is used to determine the magnitude of the wave form and possibly phase reflected at the interface of the
58. results CALL FOR A FREE COW don t have access to that kind of test two to write a complete byte into Thermocouple 8 Channel equipment To help you decide if RAM and two more to tick the A D Board MCIR Link will work with your counter or address register think this Ce cinto Thenocoupke remotes wrote a utility program to loop is the fastest one to capture SULE ON oe be aoa capture raw IR data and dump ittothe external data that you can pull off grain Gage 8 Channel serial port in logic analyzer format suggestions and improvements are Board 795 IRSIGNAL C runs on a standard IR welcome Note that the bytes are A Drect Guus OTRAS Link board with an 8K RAM in stored backwards to allow RO to e1 ustrain resolution Quarter Half amp Full brid ige co completion On board excitation voltage RD an e 795 m T lt lt m m a 00 01 02 03 04 05 o 02 Cres 100 onm patan r J J 1mA current source per channel a D 16 bit A D luti 06 07 08 09 10 16 Ke throughput 50 kHz option J J I ii digital 140 3 channel Sterner Anine ion 8 46 Channel S n E M a 12 bit A D luti it 12 13 14 15 16 Bee nossa 280 SARL ARR DARAARRANE saana naasa GERRAREARA Rake Rann tanna anasa caaee ceeae 8 In s digital VO 3 channel counter timer 17 18 19 20 21 2 Many other models available Call 420 7 _ E ia 0 1 G 1 800 648 6589 Hepe HH i corporation Figur 9 IRS
59. selectable Watchdog timer w jumper sel reset source Pre decoded extemal bus for very easy user interface directly compatible with other ADS boards see back issues of Circuit Cellar INK A Advanced Al Design H Solutions 1920 Moores Mill Road Atlanta GA 303 18 107 The Computer Applications Journal More O modulesare availble Call for our FREE catalogue today 404 352 4788 14 Issue 29 October November 1992 considered several commercially available sensors for the stem bend measurement including LVDTs ultrasonic transducers and optoelec tronics refer to Table 1 With the LVDT physical contact between its armature and the object sensed requires force resulting in deflections and incorrect measurements due to the elasticity of the geranium stem Ultrasonics Contaq Technology can make noncontact measurements however it needs relatively precise insonification of the ultrasonic beam on a specific area of a small object Standard collimating tubes do not normally ensure a measurement focused on a l to 2 mm object section In addition precision ultra sonic sensors are costly Ultrasonic Arrays amp Cosense then turned to commercial optodectronic sensors Discrete measurements from an arrayed curtain of light would be possible with an emitter receiver pair for binary blocked unblocked detection considered an b channel Sensor Terminal or PC optional Robot Controlle
60. that wait state Zilog said 60 ns should do the trick and wondered why it wasn t working Knowing didn t have a lot of time for a full blown engineering exercise neverthe less reached for the schematic and data sheets The relevant portion of the board design is shown in Figure 3 while the timing diagrams are shown in Figure 4 Identifying the likely critical path didn t take me long Highlighted in Figure 3 this path is described in words as follows The CPU outputs addresses and MREQ Memory REQuest at the start of the cycle The addresses are guaranteed to be valid before MREQ and furthermore MREQ passes through a LS245 Thus MREQ is the last signal to reach the LS138 After it arrives the LS138 will drive the EPROM CS Chip Select After CS assertion the EPROM will output data within the specified 55 ns but the circle isn t completed until that data passes through another LS245 before finally reaching the CPU Time for a little calculation First of all at 18 432 M Hz the clock cycle is roughly 55 ns so a zero wait bus EPROM 158 The Computer Applications Joumal 80C052 BASIC chip OEM 100 Qty Price BASIC 52 Prog manual BS CE US at the Embedded Systems Conference Booth 919 MOVE OVER INTEL MICROMINT SOURCES 80C72 CMOS BASIC CHIP Micromint has a more efficient s oftware compatible successor to the power hungry Intel 8052AH B
61. the need for additional circuitry or boards The boards can be jumper configured as either a master or a slave on the network and code can be down loaded and debugged across the network The GCB11 Package comes with a complete set of development tools and network and application libraries The GNU C cross compiler operates under PC DOS and includes support for C and Objective C The GNU Linker is also included The ROM Monitor D ebugger allows program downloads in S record format Break points can be set and single step step over execution is provided Read and modify features are provided for memory CPU registers 1 0 registers EEPROMS and ports An assembler and disassembler are also included Master slave packet communications software LOW COST 8051 C PACKAGE Franklin Software s new Engineer s Evaluation Kit Release I is a complete C programming package for 805 1 development at the price of a standard 805 1 assembler The kit targets engineers and students who have tried earlier C products and found them either too weak and slow or too expensive The kit allows you to experience the power and efficiency of an advanced C for 805 1 software development and maintenance Based on technology developed for Franklin s Profes sional Developer s Kit the Evaluation Kit includes a C compiler a macro assembler a linker a powerful sym bolic debugger simulator C libraries and utilities The kit features f
62. the subcarrier is regenerated CHROMA SUBCARRIER REGENERATION The circuits that reoroduce a chroma subcarrier in the same fre quency and phase as the color burst consist of a high pass filter a sample and hold phase locked loop PLL and a phase shift network and amplifier The Computer Applications Joumal R40 ik R42 C46 18k Te Aur The passive high pass filter con sists of inductors L4 and LS resistor R28 and capacitors C25 C26 and C27 The filter starts passing signals at about 3 2 MHz allowing the chroma subcarrier to pass through to the CA3126 U15 The CA3126 is a TV Chroma Processor IC designed specifically for regenerating chroma subcarriers This IC contains a VCO and a PLL with sample and hold circuits in the error correction loop As a result the VCO generated carrier is compared with the chroma signal from the high pass filter during the time that color burst is present indicated by the burst gate pulse which will describe later The regenerated carrier output is present on pin 8 of the CA3 126 Even though this carrier is phase locked to the color burst it is not at exactly the same phase as the color burst The nature of a PLL is such that the output will be locked but will always have some constant fixed phase delay relative to the input Also recall that the input circuits of the LM 1889 added HSYNC u13 LM1886 REOG BLANK7 2 syncv 2 REDD Character Data GRN g
63. the gripper THE SENSOR In 1989 I developed the first sensor for this application 4 It was based on two lo element infrared LED emitter and phototransistor receiver pairs Siemens LD260 BPX80 8 physically aligned as a 25 mm x 25 mm square Emitter receiver pairs were not multiplexed The entire first dimension was activated and latched and the same was repeated for the second dimension Both dimensions were read by a 6809 microprocessor through a parallel PIA interface The minimum object size mea sured was 5 mm in diameter or width and average position measurement errors in the x and y dimensions were The Computer Applications Joumal 2 4 mm and 2 0 mm respectively these values are within the range of expected accuracy due to the 2 5 mm resolution Response time was 115 ms repeatability was excellent and the unit insertion operation increased in performance from 80 to 98 for 204 cuttings The sensor was con nected to a single board computer the Wintek 6809 Control M odule While the position sensor per formed well needed to improve resolution and range to achieve the design goal for a minimum object size measurement of 4 mm and to over come the occasional shortcomings of the 25 mm range The resulting project won first place in the General Cat egory of the third annual Circuit Cellar Design Contest see Photo 1 It uses multiplexed emitter receiver pairs Siemens SFH405 2 SFH305 3 with a smaller c
64. two conductors The parameter v defined as Photo l The time domain reflectometer uses a 4 line by 20 character display for all operator input and output Soft keys and touch screen circuitry make for a vety flexibie interface 1 V 1l VLE VER is the velocity of the electromagnetic wave in the cable and is used to compute the physical distance to the discontinuity In a vacuum the dielectric con stant E and permeability u are equal to 8 854 x 10 2 F m and 4x x10 H m respectively so the speed of propaga tion becomes c or the speed of light Defining the equations for capacitance and inductance per unit length of the two most commonly used types of cable is also helpful For coaxial conductors inf For parallel conductors C e_ umf p Using these equations can define Z in terms of the physical and elec trical properties of the cable param eter a the diameter of the inner conductor b the diameter of the outer conductor in coaxial cables and d the distance between conductors in parallel wire cables The equationfor a coaxial conductor is The Computer Applications Joumal Za in and for a parallel conductor is Z 3 The TDR makes its basic mea surement by injecting a pulse into the cable and subsequently measuring the amplitude and phase of any reflected pulse The reflected pulse s amplitude and phase indicate the impedance of the new material T
65. wait states and the 180 boots at 9 216 MHz anyway so at least it should come up Sure enough popped the parts in hit power and success the board worked exercised my test program and everything was solid The test confirmed the S180 was functionally equivalent to the older 180 some thing that shouldn t be taken for granted when a chip is redesigned But now the time was right for the real test a double dose of megahertz OK how do I toggle the clock divide bit Oh simple just output an 80H to register 3FH Inserting an OUT 3F 80 atthe front of my program was ready for blast off entered RUN left my finger poised over the return key took a deep breath and thought Hang on to your hats Here we go Of course you know what happened when I hit that key The Issue 29 October November 1992 81 board just locked up remaining mute and unresponsive while pounded on the keyboard Finally gave up hope and reached for the board s reset switch Hmm still came up at 9 MHz When facing such a situation an inexperienced user will often jump to the conclusion the chip is busted After all the S 180 was marked ENGR SAMPLE and these things happen when you re on the bleeding edge However having done my post graduate work in the school of hard knocks know that 99 of the time the chip is busted excuse doesn t pan out An old timer will sit down
66. you use the highest performing monitor as the master some monitors may be incapable of performing at the master s mode Another way to operate this circuit with monitors that support different resolution levels or capabilities is to leave JDO ID1 and ID2 on all ports disconnected and issue manual video mode setting commands to the video board CIRCUIT USE This circuit is very easily installed and used Connect the PC video port to the input port of the circuit assem bly then the monitors to its video output ports The only restriction is connecting the lowest performing monitor to the master monitor port although even this recommendation is not absolute and depends on your application or your ability to issue video mode setting commands CONCLUSION This easily built and usable circuit is a great help on those occasions where driving multiple monitors is necessary A very low cost makes it the most sensible option when compared with similar devices most of which are offered for sale at about 500 times the cost to build this device This card has many more applications than the small number I ve suggested Just having a device like this one on hand reveals a whole new world of computing possibilities u Michael Swartzendruber is currently employed at System Integrators Inc where he works with LAN design and Macintosh programming 416 Nery Useful 417 Moderately Useful 418 Not Useful PC BOARDS e 24 h
67. 00 ms between some IR chunks Given that Timer 0 is clocked at a fixed 1 0851 ps rate I had to record 19 bits of timer information to get 569 ms of elapsed duration That s three bytes per edge and I had to keep track of the timer overflow while waiting Obviously there must be some upper limit on the number of pulses in each signal I picked 1000 pulses which seemed enough by far for any reasonable signal and allocated a 3K byte buffer in the MCIR Link s static RAM Equally obvious you should press the remote control s key just enough to generate a complete signal filling the MCIR Link s memory with repeated bursts is not a good idea Listing 1 shows the heart of the recording routine The RR_cLev variable counts the number of bytes in the serial port receiver ring buffer if it remains zero there are no incoming characters When the IS U60 detects an IR signal the IRECEIVE input bit goes low and the loop exits into the timer capture section Although the 8031 was designed and is still touted as a Boolean processor there are a few gaping holes in the instruction set The exclusive OR bit operator is conspicu ous by its absence leaving no fast clean way to detect a single bit change As a result two separate wait for next edge loops also keep track of Timer 0 overflows and check for the end of the signal After an edge occurs the code shuts off Timer 0 stores both timer bytes as well as t
68. 165 ns three clocks Yes 165 ns sounds like a lot more than 55 ns but proceed with the calculations and you ll see how the access time gets nickeled and dimed to death First of all there is a fair amount of slop at either end of the cycle The MREQ output doesn t occur until after the second half of the first clock spec 8 while the data must be given to the CPU prior to the first half of the last clock third for zero wait states spec 15 So immediately you can subtract an entire clock composed of a half clock at each end of the cycle from the available access time reducing it to 110 ns Now you have to subtract the worst case MREQ output delay spec 8 and input data setup time spec 15 According to the S180 data sheet these are 25 ns and 10 ns respectively Subtracting the combined 35 ns from 110 ns leaves us with 75 ns access time Because the board with the faster memory isn t working with a 55 ns memory where did the 20 ns go If 805 1 you haven t looked at a TTL data book in along time you may be like me and need reminding that the TTL in the critical path two stages of LS245 and the LS 138 will typically consume an astounding 30 ns Thus you re left only about 45 ns access time which explains why a 55 ns EPROM didn t cut it learned a couple lessons from this experience The memory access time required is always much less than the bus cycle time in this example
69. 17 N Exit Code Indicates Key is Available Figure 1 The generic keyboard driver routine can be broken into three sections enty contact scanning and processing Asfar as the contact scan goes it may consist of doing a row column matrix scan using a variety of methods or simply reading the key switches if they connect in a parallel fashion Debouncing is the rgection of the switch chatter that usually accompanies a key hit It includes the proper deglitching of the occur rence to prevent indicating a false closure in the event of transient noise pickup at the interface The keyboard style describes the type of action that the keyboard presents to the user A few examples of this function are two key rollover n key rollover and multikey lockout Some of these styles are the result of keyboard operation stream lining to accommodate the needs of touch typists My intention is to show how to develop a simple driver suitable for enbedded applications that are most often served by simple switch type or membrane keyboards For this applica tion multikey lockout is most appropriate Multikey lockout refers to the rejection of multiple dosures at the keypad and the recognition of a single key hit as the only valid condition for processing For solid response and proper debounce operation have the entire keyboard scanned once about every 20 ms either piecemeal or all at one time My preference is just to go a
70. 199 leave me a message on the Circuit Cellar BBS 203 871 1988 send me a fax 203 872 2204 or put your ideas on paper and send them by mail 4 Park St Vernon CT 06066 Now for next y amp s themes I ll have some specific dates for you in the next issue but didn t want to put off telling you about the topics Home amp Building Automation Embedded Interfacing Real Tiie Programming Siinal Conditioning Communication Signal Processing Graphics amp Vi Measurement amp Control Power Control amp Conversion Programmable Devices Data Acquisition Embedded Control Nothing catches your eye but you have some other ideas That s OK too There is often room in each issue for an article that doesn t strictly fit that issue s theme so we stil want to hear about those ideas BACK TO THE PRESENT We re hard at work judging this year s Circuit Cellar Design Contest entries and we ll have the results in the next issue In the meantime we have two articles in thii issue written by past Design Contest winners The MC68HC1 1 based two dimensional sensor used with a geranium planting robot won first place in the General Category last year and the Time Domain Reflectometer won first place in the Cost Effective Category the year before Be sure to keep an eye out in future issues for our new Design Contest Winner logo that now marks an author as one of the best I 2 Issue 28 AugustSepember 1992 The Computer Applications J
71. 2 SOAS TIME would like to have the address and phone number of Cypress The more I find the more challenging it gets but never too much challenge My signals are not guaranteed to be periodic as much as I wish anything in life had a guarantee am going to look at what you gave me and III leave a message if anything stops me Msg 58552 From JOE PIERSON To TERRY NORRIS You can get hold of Cypress at 800 858 18 10 try to get their CMOS BiCMOS data book Also evaluate their CY7C443 Synchronous FIFOs These can store data at 70 M Hz using the fastest non ECL memory device you can buy It is also very clean to work with since it latches all data and control lines on the rising edge of the clock input read the data sheets In addition FIFOs in general require the smallest part count of any memory storage system since they do not require the generation of address inputs as SRAMs do they generate it internally The disadvantage You guessed it they re expensive about 50 for 2K bytes But they are so easy to use that the probability is high your system will work the first time Finally it seems engineers spend a lifetime frying fo minimize noise in their circuits What about when you need to deliberately generate noise Digital or analog there s more than one way fo do ii Msg 59034 From NELSON CHANE To ALL USERS I am trying to simulate a white noise generator for a project I m working on understand this
72. A 19398 HAJAR ASSOCIATES NATIONAL ADVERTISING REPRESENTATIVES NORTHEAST Deb ra Andersen 617 769 8950 Fax 617 769 8982 MID ATLANTIC Barbara Best 908 741 7744 Fax 908 741 6623 SOUTHEAST Christa Collins 305 966 3939 Fax 305 985 8457 714 MIDWEST WEST COAST Barbara J ones amp Shelley Rainey 540 3554 ax 714 540 7103 Nanette Traetow 706 789 3080 Fax 706 789 3082 Chouk Cellar BBS 24 Hrs 300 1 200 2400 bps 8 bits no parity 1 stop bit 203 871 1988 9600 bps Courier HST 203 871 0549 Al programs and schematics in Circuit Cellar INK have been carelully reviewed to ensure their performance isin accordance with the specifications described and programs are posted on the Circuit Cellar BBS for electronic kansier by subscribers Circuit Cellar INK makes no warranties and assumes no responsiblity or lablity of any kind for errors in hese programs or schematics or for the consequences of any such errors Furthermore because of possible variation In the quality and condition of materials and workmanship of reader assembled projects Circuit Cellar INK disclaims any responsiblity for the sale and proper function of reader assembied projects based upon or from plans descriptions or information published in Circuit Cellar INK Entire contents copyright 1992 by Circuit Cellar Incorporated All rights reserved Reproduction of this publication in whole or in part without written consent fro
73. AMPLE C captures and dumpsthe first 5 5 ms of raw IR in a logic analyzer format The gap in the P eae indicate where the firmware stores the data in external RAM Each vertical tic represents one 70 Tower Office Park Wobum MA 01801 P ea FAX 617 938 6553 TEL 617 935 6668 8145 The Computer Applications Joumal Issue 29 October November 1992 71 serve as both address and counter with aD N Z instruction Figure 5 shows the first few lines of a 38 kHz signal dump Each group of ten vertical tics reoresents one byte of samples with the two blank sample periods indicating the dead time required to store the eight data bits in RAM The first IR burst is long enough that all 255 bytes are filled with carrier but that is precisely the leva of detail RSAMP L E is intended to present You can calculate the modulation frequency by finding the dapsed time for 10 or 20 cycles dividing to get the period of one cyde then taking the reciprocal to get the frequency RSAMP L E enumerates the rising edges to simplify this process the elapsed time for pulses 10 through 22 is 544 252 292 cydes 317 ps Dividing by 22 10 12 gives 26 4 ps per cycle or 37 9 kHz Many remotes need a few cycles to get up to speed so you might want to skip the pulses in the first line or two when you calculate the fre MICROWAVE SENSORS For non contact detection of Motion e Velocity Direction Point level Presence Our
74. ASIC chip The 80C52 BASIC chip was designed for indus trial use and operates beyond the limits of standard commercial grade chips Micromint s 80C52 BASIC chip is guaranteed to operate flawlessly at DC to 12 MHz over the entire industrial temperature range 40 C to 85 C Available in 40 pin DIP or PLCC 25 00 14 50 15 00 MICROMINT INC 4 PARK ST VERNON CT 06066 O TO ORDER CALL 1 800 639 3377 159 VO Write Cycle t 8051 Family Tools In Circuit Emulators The DrylCE Plus is a modular emulator designed so you can get maximum SEED eel Fae ne eer ne gee The base unit contains all the hardware necessary to support pods containing many of the most ponuer members of the 8051 family of embedded control microprocessors Buy one base unit and select one or all of the pods you need to do the job ata much reduced cost You get the same great functionality found in our popular DrylCE 8031 emulator plus real time Execute to Breakpoint Line by Line Assembler and much more And the price is almost unbelievable Yes it works with the Mac too Base Unit w RS 232 IF 299 Available Pods 149 each 8031 32 80C31 32 800154 800451 800535 80C552 562 80C652 80C51FA 8751152 87051 52 Call about 87 751 752 support 16K Trace Buffer option Avail 2nd Qtr 92 Standard 8031 DryICE Still only 199 Enhanced 8031 DrylCE 269 8051 Simulation The 8051SIM software package speeds the develo
75. C 180 BDT180 and BASIC I 1 BDT1 1 SBCs 199 SPECIAL OFFER BDT PAK combines all three versions 489 for a savings of over 100 Order today offer expires soon MIRE 40944 Coscodo Place Fremont California 94539 ysterCar inig RE 510 657 0264 FAX 510 657 5441 BBS 510 657 5442 SS 117 TOR Daughter Card 472 cs Ke OSuF PN 24 a 2N4957 R31 c 1002 T 0 Sur R10 4k 7 VCC c 0 OSuF R 4762 VREF 2 5 C10 OSuF us LT1016 POS PULSE NEG PULSE pig Ge Sra PLANE The Heart of the Matter RTXC Real Time Multitasking Executive HITACHI 6303 INTEL 80x88 x86 80x96 80x51 MOTOROLA 680x0 683xx 68HC11 68HC16 INMOS T400 T800 ZILOG Z80 Z180 Preemptive Scheduling Written in C Fixed or Dynamic Priorities Timeout on some services Configurable and ROMable Intertask Communications Messages Queues Semaphores Memory Management Resource Manager Over 50 Executive Services Available e System Level Debugging Utility System Generation Utility 450 Page User Manual Source Code Included e No Royalties e Technical Support Broad C Compiler Support Sensible License Agreement Most Popular C Compilers supported Ask about ASSIST Our new PC Development Package Combination One Time License Fee From 995 Discounts for Multiple Licenses Ports The only real time kernel you ll ever need A T BARRETT amp
76. Control DTR output Control CTS output Table I The SERCOM package contains a very basic set of serial port access functions The Computer Applications Journal Issue 29 October November 1992 35 Technical Solutions EPROM EMULATORS AND UP Downloads through standard PC compatible printer port Includes RJ 11 12 adaptor and 6 modular cable Generates RESET and RESET Accepts Binary Intel HEX Intel extended HEX and S files Unique Vertical design minimizes mechanical interference and eliminates the possibility of noise cross talk or transmission line effects from the use of a cable Multiple EE512s or EEIMs can be daisey chained for 16 24 32 bit target systems d EE256 emulates 2764 27256 99 EES12 emulates 2764 27512 129 EE1M emulates 2764 27010 179 10 day MONEY BACK GUARANTEE So day repsir replace warranty PO BOX 462101 Gar and TX 75046 2107 Voice or FAX 214 272 9392 Call or EAN for ENGINEERING SPECS Issue629 October November 1992 122 Finally you have to do the most complicated and dedicate operation in the initialization the setup of the interrupt vector and enabling serial interrupts Carefully complete this step s actions in the proper order because you are changing values inside the operating system The actions done here are 1 Save the old interrupt vectors 2 Insert the new ones 3 Notify the interrupt controller 8259 t
77. D input provided by DL_OUT is present before the comparator senses the pulse The measurement circuit operates by injecting an extremely brief pulse about 10 ns onto the cable under test This pulse travels down the cable and reflects from any discontinuities changes in impedance in the cable These reflections return to the TDR and are captured by a very fast com parator which clocks a D flip flop A precisely delayed signal derived from the original output provides the D flip flop s input The PAL generates the delay and a microprocessor can vary the delay line from 0 to 5 5 usin 20 ns steps This time resolution leads to a distance resolution of 6 feet for typical cable types and a maximum cable length of 1700 feet TERMINATION RESISTANCE Pulse amplitude measurements are made by adjusting the threshold of the comparator using a DAC until return pulses are no longer seen The reflection coefficient is calculated by comparing the transmitted pulse height with the returned pulse height If you assume the cable is lossless then calculate the termination resistance using the previously derived formula Z Zo 1 V V 1 V V Assuming a cable is lossless does simplify matters but it leads to large errors in the calculation of termination resistance for long cables The actual attenuation coefficient per 100 feet depends on cable type and quality Several standard nomographs are typically used by engineers for
78. DJ NZ RO IRTop The Computer Applications Journal point to buffer gt align to next 256 byte boundary start from the top wait for input bit 1 fetch input l add to byte repeat for full byte zat two cycles per sample external RAM next sample 2Savein 2step to PC XT AT 386 Users Photo 2 The 1S1U60 can be DIRECT fooled ty single pulses from m unmodulated remotes so E ani taiit be AN A time cutting B approach to plug in data acquisition pulses from unmodulated remotes stalled but it requires an IR photo Photo 2 shows the response to a low diode to see the raw IR signal Figure frequency square wave a 300 us pulse 4 shows the circuitry required for this each time the IR LED goes ON I have addition T1 is normally used for the also seen clusters of two or three carrier frequency calibration so make pulses for a single unmodulated input sure you remove IR Link jumper JP6 as pulse Distinguishing trash from part of the modification to prevent treasure is difficult when they look confusion S v valuable bro ae time with ADAC alike Listing 2 is the core of RSAM P L E s DIRECT CONNECT data acquistion used an oscilloscope and logic code to capture 8 bits of data and store modules FREE DIRECT VIEW analyzer to classify the remotes for each byte into external RAM Two Tora ang Da ae E this project but realize many of you cycles are needed to capture each bit quicker
79. In this case ae Bo have made the attribute equal to the register value The second call loads the register with the RGB values To use the color a program need only make the appropriate graphics library call to use the color defined by the TURBO XT WITH FLASH DISK 266 attribute In Microsoft C the call 2 Serial 1 Parallel Port would be _setcolor attribute Up to 2 Flash Drives 1 Meg Total Software Included 2 Meg DRAM EXTENDED HLS If you haven t already noticed the HLS model just described lacks the ability to define really bright or really dark colors Before the colors can get bright or dark they are unsaturated to the point of being either pure white or pure black This step is because of the double cone structure of the model 386DX Complete cPpU 1099 40Mhz IDE FDC SVGA void set_reg int reg int red 1Par 2Ser 232 422 485 Cache int green int blue Solid State Disk 2 drives to 1 5 Meg BIOS call to set color in VGA 640x480 16 color mode 1 selects register and attribute 2 sets color 0x10 regs 0x00 regs regs int86 VIDEO_IO amp regs amp regs x10 x10 regs h ah regs hal regs h bl regs h ch regs h cl regs h dh int86 VIDE0_IO amp regs amp regs unsigned char unsigned char unsigned char green unsigned char 0 0 unsigned char unsigned char set palette register reg reg set color regis
80. Issue 29 October November 1992 49 The Virtues of the Hue Lightness Saturation Color Model SPECIAL SECTION James R Furlong ave you ever wondered why graphics that use the default EGA VGA color palette look as lousy as they do Did you think your boss was kidding when he told you to mix equal leves of red and green to create yellow on your computer My Crayolas never did that Have you ever wanted to portray the shock heating of a piece of orbital debris impacting a satellite bumper shield at 6 5 kilometers per zas continuous tones of red but gave up after trial and error guessing of RGB combinations made you surmise you were color blind If you answered yes to any of the above let me assure you that a you are not alone and b a well established but little publicized color model named HLS for Hue Lightness and Saturation is the cure for your palette woes Designed by people who thought about what color means to people before how color is described for a machine the HLS moda takes the guesswork out of making colors like shocking pink or pastel green Simple analytic functions and a handful of lines of computer code create a palette of continuous tones of red or peri winkle or they can bridge dark blue with bright orange because the model s coordinates are dimensionless The following description is of the transformation equations between the HLS and RGB color models and the BIOS interrupts nece
81. NM 1952 995 86C08 adapter w analog comparators 55 414 Moderately Useful 415 Not Useful 8051 8096 68HCII 68332 SINGLE BOARD COMPUTERS We feature a seres of single board computers for process control applications Each is available asa bare printed circuit board or fully assembled and tested Optional development software is also available Please contact us to discuss your requirements and receive a literature package covering technical specsand pricing ALLEN SYSTEMS 2346 Brandon Road Columbus OH 43221 614 488 7122 The Computer Applications Journal Issue 29 October November 1992 59 Driving Multiple VGA Monitors Monitor extenders costing hundreds of dollars are available that allow you to drive multiple monitors with a single display adapter Michael uses just a touch of ingenuity to bring down the price considerably SPECIAL SECTION Michael Swartzendruber t times driving more than one monitor from a single PC video port is practical or necessary Software demonstrations or other kinds of group demonstrations are examples of one type of occasion Side by side comparisons of different brands of monitors are another Also certain artistic displays work best when more than one monitor displays an image Multiplemonitor drivers that drive from two to sixteen monitors simultaneously are currently available These devices start at about 300 and go up in price dependin
82. OM emulation for 8 bit or 16 bit operation Battery back up Optional external 9 VDC or uses the target s power e Fast loading 10K sec Accepts Intel Hex Motorola S and Binary files Fast editor allows changes in the download code e Source code written entirelyinC available for user modification All cables and accessones Included For more information or to order contact UALINK PRODUCTS 6194784678 FAX 619 578 5678 7564 Windy Ridge Road San Diego CA 92126 167 ISSUE 29 October November 1992 The Computer Applications Joumal Input Port Parallel Key Scan Figure 4 The simplest keyboard interface is to run each switch fo its own port line Such simplicity doesn t eliminate fhe need for driver software however then sequenced by the issuing of successive pulses on the dock line As the figure shows the counter s low order outputs connect to the multiplexer with the high order bits tied to the decoder The selection of row Oand column 0 occurs at reset As the counter is clocked the multiplexer sequences through all the columns until the next row is picked then it repeats until all the keys have been checked Notice in this arrangement that the hardware functions of assert ing reset and emitting dock pulses dosely follow the software counter parts of the algorithm If you re really pressed for pins you can use a little more hardware to eliminate the reset line A retrigger able one sho
83. October November 1992 Steve designed the IR Link s output circuitry to produce the data format used by the MC145030 remote control encoder decoder chip The Manchester bit cell timings are controlled by firmware interrupt routines and a 38 kHz oscillator modulates the outgoing signal Bypassing the modulation is impos sible although a trimpot adjusts the modulation frequency around 38 kHz In effect the hardware converts between real world modulated IR bursts and firmwaretimed binary pulses As long as the remote control signal looks roughly like those shown in Photo 1 the firmware should be able to both record and reproduce it Some restrictions exist though Unmodulated IR signals such as those used by many General Instrument Jerrold CAT V decoder boxes cannot be received by the IS1U60 or transmit ted by the IR Link hardware Signals modulated with carriers far from 38 kHz may not pass through the IS1U60 The Computer Applications Joumal without timing distortion and may also fall outside the IR Link transmit ter adjustment range Each IR burst must include several 38 kHz modulation cycles which means that it must be longer than a few hundred microseconds No upper limit exists but based on the remotes I ve examined a few tens of millisec onds is reasonable The IS1U60 data doesn t indude precise timings but it does respond to signals in that range Because a single cycle of 38 kHz modulation requir
84. PS2 computer with the Em high speed reliable operation In POWER ON A Tremendous time saver cludes fused power and interrupt for R amp D and production test PC XT ae support with Schematics 95 195 AT 225 PS2 325 The DPROM 2 EPROM EMULATOR with battery backup RS 232 Port and 57 6K download of HEX and S re cords Emulates 2732 27010 Units can be ganged for 27020 27 1024 2048 4096 64K Byte 150 Call for a complete data sheet pricing or engineering support An EASYBUS back plane is a AT style passive back plane that includes 3 bus switches Program control of the switches allows a processor to power down portions of the bus for repair maintenance or power reduction 895 Applied Data System Inc 409A East Preston St Baltimore MD 2 1202 1 800 541 2003 1 410 576 0335 Fax 1 410 576 0338 128 The Computer Applications ournal Issue 29 October November 1992 45 uis CA3126 LICHRONA IN CHROMA CAINS 2l aepc cHroma ouTLS urer 44 01ur c29 0 Oluf c31 C32 i oluf C4 c33 SPF T 100pF C48 eal GOpF L caa Pho LuF Y o3 Q enzzze Ae a 75Q Q a4 2Nzz22 R36 0 luF R 5 6k Figure 4d Tha CA3126 TV chroma processor is designed specifically for regenerating chrwna subcarriers The other input VIN3 is capacitively coupled to the original video input signal The JRC2244 provides internal bias sources to provide DC restoration to its video inputs The
85. R to submenu title DW OW rend of main menu ow NXTMNU PTR ALMENU PTR zero OH 3 nul to to Nextmenu program submenu data structure establishes end of structure cesses with ease For the most part we were successful Each menu item is defined within a menu structure This structure may have an unlimited number of items and is terminated by a null Each menu item consists of three words The first word is a pointer to the item s display menu string The second word has the address to jump ACC Sore keh register to if that menu item is selected The ee eee last word is defined only when a submenu is to be loaded in which case it holds the pointer to the submenu s NXTMNU l data structure ii Aii The menu system needed several A MENUPTR routines to manipulate the data A structure to operate N XTMN U isa A MNUSTCK saves the current OPTR in function created to load a submenu It a ae Asean arte saves the calling menu s address in a stack pointer parent menu Stack then it loads DPTR with a pointer to the new menu structure The function LASTMNU recovers the parent menu s table address and places that value into DPTR UPDATE M EN U scrolls menu items through the display P RI NT_M EN U updates the send of data structures for main menu gt NXTMNU A task that saves the current value in DPTR and reloads DPTR with a new menu structure Registers used DPTR Loaded with new menu table
86. The algorithm I ve presented is intentionally rudimentary keeping with the concept of the soft machine alluded to earlier If you require additional functionality consider adding a layer of code between the application and driver levels rather than tweaking the driver itself For instance if you want to remap the keys in response to the changing needs of the application place these func tions in this stub code You can place shift functions in the stub code also but with the driver I ve described these would have the shift key operate in an alternating fashion rather than in the conven tional sense because the driver only returns single key hits Actually find this action desirable usually for the types of embedded instruments that have small front panel keyboards which aren t all that easy to use anyway If you want a traditional shift key arrangement you can run the shift Z80 Z180 HD64180 HD647180 In Circuit Emulators The key outside the matrix or suppose you can tweak the driver I Il let you in on a little secret Over the years I ve developed equip ment that s run under control of various processors and controllers and interfaced to dozens of strange and wonderful keyboards but I ve only had the need to develop one keyboard driver algorithm When developing soft hardware always make sure you understand the magnitude of the task and the needs of the system make the right decisions
87. all the electronics into a small package possible This device orchestrates all the high speed operations and timing done by the system Listing 1 presents the PAL s defining code Outputting a time delay to the PAL begins a measurement The PAL includes a 6 bit presettable down counter an B to 1 digital multiplexer and a synchronizer circuit Only five of the eight multiplexer inputs are used and they are connected to the delay line chip U8 The input to the delay line is the zero output of the 6 bit counter ZR_CT The counter is clocked at 12 MHz 83 3 ns period and followed by a selectable multiplexer delay of Q 20 40 60 or 80 ns to produce the delay output The PAL operates through three data inputs that have multiple uses depending on the state of three other inputs load high LDTH load low LDTL and Go GO When LDTH goes low the PAL preloads the three high bits of the counter LDTL performs a similar function for the three low bits of the counter The static value left on the three inputs selects the multiplexer routing Note that the zero delay output ZR_CT comes out of the PAL and back into the PAL multiplexer zero delay input ZR Logically the PAL could do this routing internally but having it do so would skew the propagation delay for the zero delay output The microprocessor brings the PAL GO input low to begin a measure ment This signal is synchronized in the PAL with the next clock edge to
88. and digital I O capabilities for low end control and sensor interface applications has been introduced by DIP Inc The Pico PLC units provide digital analog PWM RS 232 I O and an auxiliary sensor power supply Integrated programming and debugging support allow the PPLC to be programmed using a standard data terminal or PC No specialized programming software is required Extending the control language typically found in low end PLC units with a full set of arithmetic and comparison operators the PPLC products allow the user to intermix analog and digital operations using ladder logic formatted command strings The unit may be put into a single step or display mode for interactive debug ging File transfers are supported to and from a PC programming unit using standard PC based communica tions packages EEPROM program storage provides for 256 program elements with an average execution time of 50 us per element The PPLC will replace combinations of discrete relays counters timers and comparators in applications such as production monitoring intelligent sensor interfaces front end preprocessing for larger program mable controllers sequence control and low end motion control systems requiring peripheral interfaces A comprehensive programming guide cuts the learning time to less than two hours The base unit PPLC provides four inputs 120 VAC four outputs 120 VAC 2 amps two analog channels O IO VDC a PWM output open col
89. and do use a variety of cable types M ost of them fall into two categories coaxial and twisted pair Each category has its own characteristic impedance The problem is TDR has its own intrinsic characteristic impedance which may or may not match the cable under test so there may be reflections generated at the interface of the TDR and the cable under test The Computer Applications J ournal Rejecting this reflection with software is possible but the noise margin will be affected Unfortunately some portion of the waveform s power also will return before it reaches the cable fault further reducing the instrument s usable range Initially we thought this problem meant a reduc tion in supported cable types because some form of internal termination was required to perform the measurement In the end we decided to cover the two most common types of coaxial cables with a very small relay which toggles the TDR s internal termination resistance between 50 and 75 ohms HARDWARE DESIGN The electronics for the system consist of two major parts microcon troller and measurement The micro controller electronics include the LCD display DAC and IR touch screen circuits The measurement electronics consist of a high speed comparator a low power latching relay and a discrete cable interface circuit The microcontroller is an 87C51 operating at 12 M Hz see Figure 2 The microcontroller s oscillator also clocks the measu
90. ar phone jack permits direct connection to either the PL513 or the TW523 A short piece of ribbon cable off of the square pin header simplifies interconnections between PLIX and your port bits Finally power is supplied by a 9 volt battery If you don t have a controller project in the works and can t directly connect to PLM but still want to experiment you are in luck The PLIX demo board will also interface to your PC s parallel printer port Because the PC printer port is not a true bidirec tional port the data must be read in through the status port as nybbles which adds a bit more complexity to the circuit The low power of the PLIX chip allows battery operation The routines written for the PC s parallel port are written in BASIC but are adaptable to any language includ ing straight assembly language The quick evaluation of PLJX is this demo board s purpose Once you see the benefits of using PLIX you will likely want to include it in your future X 10 designs 153 The Computer Applications Journal Jeff Bachiochi pronounced BAH key AH key is an electrical engineer on the Computer Applications Journal s engineering staff His background includes product design and manufac turing SOURCE Micromint Inc 4 Park St Vernon CT 06066 203 871 6170 1 PLIX Chip and Data Sheet 20 2 PLIX EKit Evaluation Board Includes PLIX chip data sheet PCB with all components applic
91. ast compilation and highly optimized object code Execution speed is comparable to the best in the industry and performance is equal to a tightly coded assembler provides rapid development of distributed control applications at various baud rates up to 115 2 kbps Application utilities include a PWM motor driver library for transparent support of up to four DC motors encoder feedback for speed and position control of up to three motors input signal debounce library and support for ADC sampling at regular intervals as a background task Source code for all software is provided C and assembler The complete GCB1 1 package sells for 179 Coactive Aesthetics Inc P O Box 425967 San Francisco CA 94142 415 626 5152 Fax 415 626 6320 501 The Engineer s Evaluation Kit is an entry level companion to and fully upgradable to Franklin s Professional Development Kit for the 805 1 Priced during introduction at 299 plus an optional support contract the C kit is an affordable way for engineers to discover the advantages of a complete C environment for 8051 development Franklin Software Inc 888 Saratoga Ave 2 San Jose CA 95129 800 283 4080 Ext 896 Fax 468 296 8061 502 The Computer Applications Joumal Issue 29 October November 1992 NTA De eee NEWS 8 PROGRAMMABLE RELAY CONTROLLER PROVIDES ANALOG AND DIGITAL SUPPORT A family of programmable relay controllers with both analog
92. at if trapezoidal like functions for BLUE GREEN and RED are used which only differ from each other by their starting hue point the entire hue coordinate can be traversed to mimic the color transitions shown in Figure 1 For example starting from HUE 0 and tracing through the functions in Figure 2 BLUE is the only function with a positive value Advancing to HUE 1 6 BLUE remains constant while GREEN begins to increase eventually equaling BLUE The equal levels of BLUE and GREEN create the familiar cyan hue If you continue to trace through the functions for 1 6 lt HUE lt 1 3 GREEN remains constant while BLUE is brought to 0 resulting in the green hue at HUE 1 3 A subsequent tracing through the functions will show that the growth and attenuation experienced by GREEN repeats for the other two colors first for RED at HUE 1 3 and then for BLUE at HUE 2 3 AtHUE 1 you have come full circle and are back at blue Defining the trapezoidal like functions for RED GREEN and BLUE requires nothing more than superpos ing linear functions with different amplitude offsets For example the Issue 29 October November 1992 51 function BLUE over the interval 0 lt HUE lt 1 6 is defined by BLUE f1 fo where fle pp x 2 and f x 1 where x represents HUE and axis a constant equaling 1 6 These two functions will maintain BLUE ata constant value of 1 indefinitely BLUE needs to be attenuated for x gt 1 6 wh
93. ation note and PC compatible software on CiSK iin di csecis ete ee aw tet 29 Add 20 for TW523 X 10 transceiver module sold with PLIX EKit only Shipping extra 422 Very Useful 423 Moderately Useful 424 Not Useful issue 29 October November 1992 79 I m 18 432 and Like It Some people just can t get enough horsepower out of their processors and Tom is certainly one of them Zilog s newest speed demon runs the faithful Z180 HD64180 up to 18 432 MHz and beyond 80 Issue X29 October November 1992 SILICON UPDATE Tom Cantrell ometime during the 70s Alice Cooper paid homage to those with raging hormones by making his classic statement I m 18 and like it Today many of us yearn for a return to the days of our youth when we were strong and good looking Meanwhile Alice who still wears tights and makeup 20 years later barely made it out of adolescence before jumping directly into mid life crisis Come on Alice update our generation s anthen how about I m middle aged and it stinks Baby boomers and the like aren t the only ones having mid life crises ICs are having them too Chips that once were the darlings of industry have ended up feeble commodities Now a chip unlike the typical burnt out Silicon Valley executive can t turn to Grecian formula a Nehru jacket and singles bars for a mid life kicker However as will show old c
94. ator The intuitiveness and elegance of the HLS model become apparent when it is compared to RGB Take pastel green for example Under RGB you would first set the lightness of green with GREEN intensity but to soften the green you would have to add equal levels of BLUE and RED That doesn t really make sense does it Under HLS you would first set HUE to green then make the green as bright or dark as you want with LIGHTNESS and as pastel as you want with SATURA TION Furthermore pastel green happens to be one of the easier colors to make under RGB because equal levels of The Computer Applications Joumal BLUE and RED arean exact comple ment of GREEN If you shift the color from pastel green to say pastel cyan cyan is equidistant from BLUE and GREEN then the ratio between BLUE and RED would no longer be unity and you would need an ambiguous combination of BLUE and RED to soften the cyan TRANSFORMATION EQUATIONS The process of creating the HLS transformation equations begins by recognizing the relationship between RGB and the hue coordinate Figure 2 lays out HUE in one dimension Although HUE is the azimuth coordi nate and should be referred to by angle have normalized its value to 1 maintaining consistency with the other coordinates You can make the starting point any value you want because the hue coordinate is circular In my system HUE 0 is defined as blue With a little imagination you can see th
95. both input and output which means the program using the serial input does not have to monitor the serial I O line constantly This arrangement is a major failing of the polling BIOS serial I O If your program is busy doing something else when a burst of characters arrives you will get only a few characters and the rest will be dropped The solution to this polling problem is to lower the data rate so the program will be able to check the line before another character can arrive Using SERCOM routines is like using the file operations of stdio h In this case you include the header file SERCOM H inall the modules of your program that you want to use the serial I O routines Listing 1 shows a skeleton for serial I O Again like file operations these routines let you have more than one open at a time The supplied version of SERCOM limits you to two because standard PCs only support two ports If you want to open more than two ports at a time you will have to add their register and interrupt locations You may open as many ports as you have hardware Table 1 shows the functions available when the port is opened What each function does is obvious but the comments in the SERCOM program source code provide descrip tions of them Table 1 also shows a number of functions used a little less often If you start your serial I O program on the PC then connect it to your remote system plugging in the cables will probably gen
96. but in practice it s a source of confusion for those of us trying to make sense of everything Some mostly older remotes use unmodulated pulses simply turning their IR LED on to send a pulse and off when it is done These units tend to be more sensitive to interference from stray IR because there is no way to Data Chunks ee ee es S AQT a Data Bits ee TU IR Transmitter LED Carrier Period 1540 us typical IR Carrier Pulses On Off Figure 2 Although remote controls use many different techniques to encode their information into the infrared signals this sketch ifustrates Some of the common features controls is in order although you should be reasonably familiar with them from articles about the original Master Controller the IR Link and similar projects M ost infrared remote control units use modulated IR signals as shown in Figure 2 An IR signal is made up of large chunks for lack of a better term containing bits which are bursts of IR pulses at a usually constant carrier The Computer Applications Journal distinguish a glitch from a real bit H owever even these units do not have a universal bit encoding method Photo 1 presents a rogue s gallery of IR signals taken from a shopping bag full portion of Steve s remote control collection Notice the different horizontal sweep speeds required to capture the signals the number of bursts in each chunk the timing variations and th
97. by an embedded system The choice is usually based on the need to strike a balance among overall system necessities complexity and cost As an example you can use a UART to fulfill asynchronous serial communications or alternatively you can take a firmware only approach Furthermore depending on system requirements the firmware based approach can perform as a dedicated loop that basically shuts down all other operations and bangs the bits using enbedded timing loops You can refine this approach by referencing the timing to a timer interrupt where other system functions can continue to be serviced as wal As usual any choice you make is relative and the demands of the system under consider ation dictate what s appropriate and effective The Computer Applications ournal A system that simply uploads collected data to the host computer when in a dedicated dump mode has no penalty regarding the suspension of other system functions This lack of restriction exists to perform the communications chores entirely in firmware using simple bit banging When performing communica tions on an intermittent basis with a system that has to renain live running the communications in firmware while off loading the timing burden to a timer interrupt may be appropriate because some processing power is available for other functions Of course if the system in question must be on line in a networked environment with heavy communica tion
98. can be accom plished using some shift registers and XORs The band width want for the noise is DC to 5 kHz I ve checked a few sources TI and National Semiconductor had white noise generators but they ve recently obsoleted them Can anyone help me find a solution to this Can pin diodes and an amplifier be used Any ideas Msg 59043 From RUSS REISS To NELSON CHANE Yes you can use a feedback shift register to generate pseudorandom noise pseudo since it actually repeats at the length of the sequence There are particular feedback taps that permit maximal length shift codes sequences for MICROCONTROLLER BOARD WITH 128 kB FLASH EPROM 8031 a Monitor and Flash Manager software are providedin the protected boot block Parameters and main blocks are user programmable and erasable on board 128 kB Flash EPROM has an 8 kB boot block two 4 kB parameter blocks andone 112 kB main block Software source code is Included Serial RS232 with MAX232 chip 5Vand 12V supplies Two20pin headersforportlinesandexpansron 110592 MHz Clock Speed Assembled and tested board with documentation 80 00 Kits power supplies and application software are available Ask for more information and price list L S ELECTRONICSYSTEMS Aa 2280 Camilla Rd Mississauga SS Ontario Canada L5A 2J8 Phone Fax 416 277 4893 BBS 416 277 0047 DESIGN E Now includes color reduction Vidor 2 Image Processing Library Load and ga
99. cate no timeout Rawl MOV A RR_cLev Llmonitor serial character count LJ NZ RawDone 2and bail out if any show up CPL HEARTBEAT sl indicate we are alive JB IRECEIVE Rawl 2 high with no IRsignal CLR FlagMCSavelR 1force memory low to match hold off interrupts and start timer at zero PUSH IE CLR EA 2 save existing interrupt state Ishut them off entirely CLR TRO MOV TLO 0 MOV THO 0 CLR TFO SETB TRO 1 reset the timer repeat for each time entry in array or until signal times out MOV B 0 2 clear wrap counter accumulator RawLlp JB FlagMCSavelR RawUO 2 which bit did we have last time RawDO CPL HEARTBEAT slindicate we are alive JNB TF0 RawD1 s2check for timeout CLR TFO INC B JB B 3 RawT0 RawD1 JNB ITRECEIVE RawDO SETB FlagMCSavelR S MP RawEdge time out after 8 wraps gt 2 spin if still down lremember new bit state RawT0 ORL ErrFlags 20 record for debugging SETB FOFLAG zand force loop exit S MP RawEdge after normal recording Rawl0 CPL HEARTBEAT J NB TFO RawU1 CLR TFO INC B 1 JB B 3 RawT0 2 time out after 8 wraps RawU1 JB IRECEIVE RawU0 CLR FlagMCSavelR slindicate we are alive s2check for timeout 2 spin if still up slremember new bit state edge detected store current timestamp RawEdge CLR TRO MOV A B MOV C TFO ADDC A 0 MOV B A MOV R4 TLO slfreeze timer slpick up wrap counter slincorporate possible wrap slsave it for lat
100. cognized and is therefore valid DEBOUNCED issettoaoneand KEY_ NUMBER may be used as an index into a lookup table to extract the decoded value for this key which can be a scan code or an ASCII code depending on the usage The decoded key is then returned to the calling program with the exit code set to the appropriate state Figure 1 summarizes these steps HARDWARE TECHNIQUES Having established how you want to do the general keyboard scanning turn your attention to combining the general principals with some hard ware The classic method of interfac ing a keyboard to a microcontroller is based on the matrix scan where the key contacts are connected as an array consisting of driven rows and scanned columns With the rows diode coupled as shown the circuit is able to dis Figun 2 A popular keyboard scanning scheme uses one ing for each row and one for each column Each row is successively energized and the columns are read to detect a keypress The Computer Applications Joumal outputs together if someone presses the wrong two keys at the same time The benefit of this organization is the reduction in the number of port pins required for the interface For example if you scan 16 keys four outputs and four inputs will be consumed To proceed turn on a single drive line and then read the columns Repeat by driving each row in sequence Figure 2 shows how this process is done Port pins ar
101. construction applies to product design guess that s why enjoy being an engineer If you choose the correct mix of components your design will withstand the test of time or gravity If not well that s how we got the term smoke test One of the most widely discussed topics herein the Computer Applica tions Journal and on the Circuit Cellar BBS is home control X 10 control is a favorite subject within this topic Let me show you how the new PLIX Power Line Control for X 10 chip can ease you into X 10 control without even breaking a sweat and why you should consider using a chip to handle X 10 communication in your next design think you ll find this blend a perfect one WHERE WE VE BEEN Many of us have been using X 10 modules for appliance control for over ten years X 10 Powerhouse remains unchallenged as the leader in power line carrier transmission control systems CEBus s PLBus may render X 10 s code transmission format obso lete but its large installed user base will prevent that from happening any time soon For more information see the assorted CEBus articles by Ken Davidson in issues 10 15 and 21 of Circuit Cellar INK soxonnun E Housecode A B c D E F G H l K L M N 0 P Function All Units Off All Lights On On off Dim Bright All Lights Ott Extended Code Hail Request Hail Acknowledge Preset Dim Low Preset Dim Hig
102. copy Free Demo Disk Call Today Toll Free 1 800 221 6630 ife 17455 68th Ave NE Suite 304 Bothell WA 98011 USA 206 486 8086 fax 206 486 0253 120 The Computer Applications Joumal Issue X29 October November 1992 31 and RG 59 Unfortunately the attenuation is not linear Though the TDR makes this simplification it is able to compute termination resis tances accurate to about 1 for cables up to 100 feet The accuracy of the termination resistance readout gets worse from here because the attenua tion effect was empirically character ized out to 1700 feet It is probably in the 10 range SOFTWARE DESIGN The software for the TDR is very simple and straightforward with the exception of the menu system and the
103. correct ing reflection coefficient for line loss The TDR handles this problem by first determining the cable s length and the uncorrected reflection coeffi cient using the algorithm I ve de scribed It then corrects the reflection coefficient for line loss based on the measured length before using the injected pulse amplitude in the previous equation The voltage attenuation constants for RG 58 and RG 59 are stored in firmware They are approximately 3 per 100 feet of length for both RG 58 DOS Where You Want It Runs on Disk ROM FLASH Develop your programs on a standard PC and run them in ROM with ROM DOS the flexible affordable operating system that was designed for embedded applications Compat ible with MS DOS 3 3 1 ROM DOS boots and runs from ROM disk or FLASH memory Features include small size low as 36K runs executable files from ROM FLASH disk support remote disk and multimedia support and a powerful utility suite Confirmed compatible by VeriTest an independ ent evaluator ROM DOS is already in widespread use on multiple system types Developers Kit which contains all the tools and utilities needed to configure ROM DOS to your Already inwidespread use on a variety Of _ platforms ROM DOS has proven its dependability system and includes license for 20 copies costs only 495 ROM DOS royalty fees depend on quantity purchased and range from 3 to 25 per
104. des the RS 232 to TTL conversion for both the transmitter and receiver U16 a 75176 provides the RS 485 to TTL conver sion JP1 connects the receiver pin of the 87C054 to either the RS 232 or RS 485 interfaces The transmitter pin of the 87C054 connects to both the RS 232 and RS 485 interfaces One pin of the 87C054 P3 5 controls the driver enable of the 75176 allowing for selective talking on the HCS II net work JP3 provides for termination of the network But wait a minute The 87C054 doesn t have a UART you say True There is no built in UART on the EMEA 812 2123 ibe E TETE Rental And 10 Day Trials Available m iceMASTER delivers productivity easy to leam easy to use ond fast m Hyperlinked On line help guides you through the emulation process iceMASTER is FAST The 11 5 2K baud serial link keeps typical download times to under 3 seconds using a standard COMM port Broad support of derivative devices Flexible user interface you can completely config ure the windows for size content location and color Call today for FREE DEMO DISK Call today to ask about FREE 8051 Macro Assembler 800 METAICE 800 638 2423 Metalink Corporation PO Box 1329 Chandler Az 85244 1329 Phone 602 926 0797 FAX 602 926 1198 TELEX 4998050MTLNK iceMASTER Improved User Interface Features iceMASTER is convenient t connects easily to your PC requires no disassembly
105. e characteristic some Issue 29 October November 1992 65 LENE E SE SE SE He FE 8 gt 3 G SRS Mak E cae e L amc entree a ena u sa mae e m w e ws Photo l Common hand held 4R remote control units use a vast army olcoding schemes and timings The scope was set for 20 ms per division on he fop trace in all six photos The bottom trace was set for 10 ms per division in the top four photos 5 ms per division in the bottom lef photo and 2 ms per division in he bottom right photo Also note he differences in repeat rate among he remotes remotes have of not repeating the same chunk over and over How to capture store and replay this wonderful variety of signals GROUND RULES The IR Link board sees infrared signals through a Sharp IS1U60 receiver that expects bursts made up of IR pulses repeating at a 38 kHz rate While it can handle other carrier frequencies roughly 25 60 kHz for very strong signals its internal bandpass filter reduces the sensitivity so the maximum distance drops off dramatically as the frequency varies from 38 kHz The output is a low going pulse starting 50 100 ps after the IR burst begins and ending 100 300 ps after the signal shuts off The specifi cation sheet is silent about actual timing limits but it s reasonable to assume the turn on and turn off delays depend on the signal strength carrier frequency background light level and most likely the phase of the moon 66 Issue 29
106. e general sinu soid and will be divided out What remains is an equation relating the complex amplitude of the incident waveform to the load impedance Z and the characteristic impedance Z V Z _ Adit Aidt 2 ZI o Ze AO AM A A TATA A Z Z A Z Z This equation is the definitive relationship for TDR With it you can anticipate the reflection of any 24 Issue 29 October November 1992 waveform with predictable results In the limit with Zo equal to zero A equals A and shows that the inddent waveform will be entirely reflected with a 180 phase change When the load impedance is infinite A equals A and the entire waveform reflects but this time without a phase change As long as the load impedance is purely resistive and does not equal the characteristic impedance exactly the reflected wave will have at least some portion of its power reflected with either a 0 or al80 phase change Not surprisingly you will observe a phase change other than 0 or 180 when the load is reactive An understanding of how power dissipates in the transmission line explains why a portion of the wave reflects at all Power V y v iur 3cV Because the equations developed in the preceding paragraphs are based upon a lossless transmission line power dissipation only occurs by transmitting power from one section of the cable to the following section It The Computer Applications ournal does
107. e often in short supply Similarly a congested PCB layout may mean you need to conserve lines because the keyboard is on another card or even located remotely to the controller With a little extra hard ware you can get by using just three Figure 3 When port lines are scarce a litte more port pins two outputs and one input hardware drops the interface down to just three lines A As shown in Figure 3 a decoder in 4 M counter is used b cycle through the rows and this case using active high output and Binary Counter Decoder nee a multiplexer operate under control of criminate at least two simultaneous a binary counter to perform the key closures at a time although the functions done previously in firmware algorithm does not make use of this Here the hardware performs the capability In any case this arrange sequencing The counter s reset pin ment prevents the jamming of two initially resets the matrix which is Chart Your Course To Improved Real Time Design Processor Selection and System Prototyping Find the shortest route through your next embedded system project with ViewTask from US Software With ViewTask you can design an operating task set on your PC complete with timing parameters and your choice of processor to run a series of what if scenarios Then use your monitor to evaluate worst case timings and verify task set viability you can even generate executable tasking code all for only 495 C
108. efine the intial posi tion of the start of the OSD Once the initial vertical and horizontal positions have been found the 87C054 will fetch characters from the OSDRAM and place them sequentially on the screen In order to have multiple rows ters are 14 dots wide stores the characters of text a special character has been defined and is referred to as NEWLZNE The NE WLINE character is much like a carriage return line feed sequence on a computer in that it terminates the current row of characters and starts a new row of text One advantage of this architecture is that it eliminates the need to pad display memory with space characters The fetching and painting of rows of text will continue until either a new vertical sync pulse is detected or until an END attribute is fetched along with a NEWLZNE char acter NOW FOR THE DETAILS Now that you understand the concepts of an OSD operation and the capabilities of the 87C054 focus your attention on the details required to overlay characters onto live video The 87C054 OSD has a multi plexer output for switching video sources Simply switching between the input video signal and the OSD charac ter data would be nice Unfortunately you can t because the input video from our home entertainment center is in NTSC format and the character data is in RGB format Keep in mind that the goal is to input live video add on screen text and present the result as a video sig
109. eg ct5 0 sg zr_ct registered outs define relationships begin define groups group ifi2 0 group ct ct5 0 group mux i2 0 group d zr80 zr60 zr40 zr20 zr clocks ctL ck clk do output enables PrPrPrPrPr oy yc cto have to do this to get feedback do aclr and spre x7 zr_ct aclr 0 Sg pre 0 zr_ct pre 0 ct J aclr 0 ct pre 0 define mux action load low and high and count dlout d mux mux high level construct if go 1 if go high wait for load or hang if ldtl 1 amp amp Idth 1 if both loads high just stay here sg 0 sync go 0 no pulse zrict 0 zr_ct 0 input to delay line ct ctf don t decrement counter hang else if ldtl 0 if one or more loads are low then if load low load in to low ct continued The Computer Applications J our nal the minimum signal to noise ratio so critical portions of the measurement circuits are located on a small very tightly hand wired daughter board see Figure 4 with a ground plane These key circuits include the termination relay the comparator and the D flip flop The logic board contains the less critical portions of the measurement circuit The heart of the measurement circuit is U9 a low power high speed PAL device ICT 22CV10Z It reduces the chip count by as much as four MSI logic devices and makes fitting
110. er continued The Computer Applications J our nal Listing 1 continued MOV R5 THO 3 2 CLR TFO SETB TRO sland MOV A R4 MOVX DPTR A INC DPTR MOV A R5 MOVX DPTR A INC DPTR MOV A B MOVX DPTR A INC DPTR decide if we are done yet JB FOFLAG RawEnd DecRR J NZRR R3 R2 data will fit in two bytes rather than three The division which is imple mented as a bit shift preserves the remainder and adds it to the next time Thus each regenerated time may be in error by up to 7 us but there is no cumulative error Most of the remote control signals measured started with a long lead in pulse and a long delay then had relatively short bursts in each succes sive chunk Chunks might be sepa rated by long pauses but there were also few cases where long and short delays were mixed together A simple run length encoding compression scheme seemed to offer the best trade off of complexity and efficiency The division by eight means that time intervals less than 2 21 ms 255 x 8 x 1 085 ys require only one byte Values longer than that require two bytes and no values bigger than that 01 00 1200 CO 03 F2 01 Block ID Number 1 Number of pulses 18 38 B9 38 B9 37 40 37 40 36 the data BA 38 B8 38 3F 37 B9 39 B8 38 3F 37 40 37 B9 38 B9 38 B8 38 B8 39 3F 01 Number of pulses in two byte format 1 four bytes total 3800 EA ED 00 00 timer restart it slclear store the First pu
111. er 1992 The Computer Applications Journal
112. er Applications Journal Msg 58298 From MATTHEW TAYLOR To TERRY NORRIS just left a scientific government agency where one of the guys was working on a 1 GHz data acquisition box for ground penetrating radar The converters were from Tektronix and the boards consisted of 50 amps of ECL logic To get the required throughput there were several banks of converters and each was fired in succession over and over until the 4 ns bank of static RAM was filled up Maybe this technique would work for you application stagger several slower and cheaper converters and fire them in order to get up to the speed you need Msg 58422 From TERRY NORRIS To MATTHEW TAYLOR Unless learn something new it seems the most effective way to build this circuit is to have a 100 MHz ADC working at full speed to store data in some high speed RAM Then have the RAM accessed by a DSP or two don t think the CCD that Tektronics uses will be too cost effective I hear now that if something goes on the 2430 scope it is the CCD All of this will yield what want if Cross Assemblers trom 50 00 Simulators trom 100 00 Cross Disassemblers from 100 00 Developer Packages from 200 00 a 50 00 Savings Make Programming Easy Our Macro Cross assemblers are easy to use With powerful conditional assembly and unlimited include files Get It Debugged FAST Don t wait until the hardware is finished Debug your software with our Simulators Recover L
113. erate a few garbage characters In a case like this example a call to cl ean_ser ensures the input buffer is empty MTERM A DEMONSTRATION PROGRAM Included with the source code is a simple terminal emulator program called MT E RM developed this program to talk to the Motorola EVM board and also included the capability to down load S19 files to it Listing 1 A skeleton C program shows how a serial port is defined opened and closed include lt stdio h gt include lt bios h gt include sercom h main COM ser Open the serial buffer ser if ser NULL exit 1 Flag error Insert main program here Close the serial port must be rebooted before the next ser_close ser Writing a terminal emulator using the functions in S ERCOM is simple At the heart is a loop that monitors the PC keyboard using kst at and the serial I O line using ser tst If a character is seen on the keyboard it is read and sent to the serial port If one is seen on the serial port it is read and sent to the PC screen When a key is typed on the PC keyboard the remote serial device must echo it before it appears on the screen MTERM can both capture received data and transfer files The program easily sends all the received data to and from a file just like it came from the keyboard SERCOM INTERNALS MostofthecodeinSERCOM Cis very simple but two areas deserve further explanation i
114. es about 26 ps and the IS1U60 response time specifica tions are extremely vague recording the burst times to the exact microsec ond is pointless As you will see later this flexibility allows a data compres sion method capable of reducing the stored data by roughly a factor of two GOING ON RECORD Recording a IR signal using the MCIR Link is simple at least in principle You start a timer on the leading edge of the first pulse and record the time of each successive edge The two pairs of times for each pulse the ON and OFF durations should be sufficient to reproduce the pulse Unfortunately the 8031 does not include a timer that can be controlled by an external signal in that manner so it s done with firmware Because I was already using Timer 0 to send and receive the IR Link s MC145030 pulses adapting it to the MCTIR Link functions made sense Timer Mode 1 selects a 16 bit up counter clocked at 1 0851 ps for an 11 0592 MHz crystal and the TRO bit enables and disables the clock signal to start and stop the timer Starting is no problem just wait for an input pulse from the IS1U60 This step is somewhat complicated because you do not want to hang the system if you decide not to send a signal so I used a short loop that bails out if a character shows up at the serial port But as the saying goes The trouble with doing nothing is it s hard to know when you re done for the day When recording IR signals
115. etwork consisting of Cl3 and R28 through Cl 1 and R30 respectively These transistors provide microcon troller input P1 3 P14 and P1 5 When an LED is turned on its respective phototransistor conducts about 2 mA with a fast falling edge Differentiating capacitors pass this fast edge with a time constant of 50 ps The pulse turns off the NPN transis tor producing a 50 ps high on the processor s input for each falling edge on its LED The software samples the phototransistor outputs briefly after it turns on an LED If it sees a high input then the light from the LED must be reaching the phototransistor so a key must not be pressed MEASUREMENT ELECTRONICS The maximum resolution in termination resistance is limited by 28 Issue 29 October November 1992 Listing The TDR PAL is defined using a high level description to let the compiler make better use of the part and to reduce the number of outputs RIKKI KIKI de de e Fe e e He de He RK KKK IK IK KKK He Fe e e IK KKH KKK KIKI KEK IK KKK K J TIME DOMAIN REFLECTOMETER PAL It does the following 6 bit programmable down ctr Idin two 1 2 s Idth l dtl zr_ct goes high at zero synchronizes go output falling edge of go in and clock multiplexes dallas delay generator on inputs BI II I ICT IO IK I e de de IOI I e de HE TK TOK e e Fe IK KKH HK KH He KH HAH KI HK KIKI KEI KER TDR in clk i2 0 1dt1 idth go zr zr20 zr40 zr60 zr80 inputs out dlout r
116. f variability is contrary to a typical industrial application where an attempt is made to eliminate any inconsistencies Dr Ward Simonton developed a robotic workcell for the labor inten sive preparation of geranium cuttings Company item Model Name No for propagation to be used as a case study A conveyor brings geranium cuttings into a robot work envelope Using machine vision the supervisory computer locates a cutting and dassifies all primary plant parts Knowledge of plant structure is used to grade and determine an appropriate processing strategy Control is passed to the robot and end effector controllers The robot grasps a single cutting from the conveyor with a gripper moves it to a pneumatic device for leaf removal if necessary takes it to a pneumatic cutter for stem trimming and inserts it into a plug of propagation medium in this case peat Fixtures and sensors mounted within the work space assist the processing Figure 1 THE CHALLENGE The problem the robot had early on was it damaged a significant number of cuttings Its strictly vertical insertion motion into the plug did not regard the bend in the geranium stem It could neither recognize different relative angles of stem growth fre quently found on cuttings nor the change in stem orientation during workcell preparation For the reliable insertion of cuttings into plugs the direction and degree of bend at the base of the stem had to be determi
117. ference is the shrink from a 1 Smicron to a1 2 micron process A less obvious reason is that the static design just as for memories eliminates the need to refresh internal circuits like the register file A programmable divide by I or divide by 2 clock option is a really nice touch Zilog added The original 180 requires a 2x clock input so my board had an 18 432 MHz crystal running the CPU at 9 2 16 MHz the weird clock rates are called for by the 180 on chip baud rate generator When the S180 is reset the program mable clock divide is set to 2 thus the 180 also comes up running at 9 216 MHz A single 0UT instruction can then toggle the divide bit to Ix and speed things up The Computer Applications Journal This result means existing 180 designs can be upgraded without changing the crystal That s good because wasn t looking forward to doing the switch my soldering skills are definitely not improving with age As the presentation ended thought that this upgrade a simple change of three chips the 180 BASIC EPROM and SRAM would be about as easy as one can get Once in the lab we dug up an 85 ns EPROM and a 35 ns SRAM I d been told that the 20 MHz S180 required memories of about 60 ns Even relaxing that to reflect 18 432 MHz operation realized I d need at least one wait state to deal with the EPROM No problem I d programmed the BASIC EPROM to boot up with the maximum number of
118. g 58248 From GUY RESH To TERRY NORRIS Well depending on your application there ARE 100 MHz DSO boards for the PC line Give Gage Applied Sciences Inc a call 514 337 6893 They ve got a few boards ranging from around 1500 up to 10 000 Steep but if you want to play with those frequencies you re going to need the proper tools am _l_ actually saying this The reason say that is I m in the same ballpark and want to do the same thing or so it sounds If you don t mind a repeti tive sampling there are cheaper boards on the market that sample at 20 MS s with a 50 100 MHz bandwidth All depends on your requirenents Rolling your own is going to be challenging to say the least Analog Devices and TRW are two of the major suppliers of ADC chips that will do what you want be prepared for gt 75 per chip though Heck Tek will sell you a single chip for 1875 00 if you want REAL quality G luck Msg 58369 From TERRY NORRIS To GUY RESH It is interesting that you mention Tektronics because found that they used an analog shift register in their 2430A oscilloscope They used a charge coupled device CCD for acronym people to shift the data in at 100 MHz then shifted out the data to a lower priced than 1870 analog to digital converter also have data on Analog Devices ADCs and still wish for more knowledge but at least am not out in left fidd 96 Issue 29 October November 1992 The Comput
119. g on the number of monitors the device can drive However the simple circuit describe here is an alternative that addresses these problems at a much lower cost built the core of this drcuit with three low cost transistor chip arrays and a handful of resistors Moreover you can duplicate the core ad infinitum to drive as many moni tors as demanded by the task at hand THE CIRCUIT Figure 1 shows my multiple monitor driver This simple device implements any number of parallel emitter follower amplifiers which serve three essential purposes The first is to provide a properly termi nated load to the video card in the computer Second these amplifiers serve as isolation amplifiers between the PC video card and the multiple monitors being driven from the video source The third purpose of these amplifiers is to provide drive current to the inputs of the monitors con nected to the circuit Notice that the base of the driver drcuits transistors connect to ground through a 75 ohm resistor As mentioned before this resistance is provides the proper amount of load resistance to the PC video card The base of each monitor s driver amplifier connects to this point The multiple bases connected to this resistor do not alter the 75 ohm termination resis tance appreciably allowing multiple emitter followers to be driven from the video card In turn this feature is what allows the PC video card to drive multiple moni
120. ginning and the end of the buffer at the receive channel you will see that the head pointer stores a character each time the hardware generates a received character interrupt The character will be read from the hardware inserted into the ring buffer at the head pointer location and the pointer is advanced The entire process happens in the background You can then get one character from the buffer by a SERCOM call The character is taken from the tail pointer location and the tail pointer is advanced Each time a character is added to buffer the head pointer is advanced If the pointer hits the physical end of the buffer it is reset to the start which is where the ring in the ring buffer comes from When the head and tail pointers point to the same location in the buffer it is either full or empty The program keeps a count of the number of characters in the buffer at all times so distinguish ing between full and empty is easy The ring output buffer is run the same way except the noninterrupt part of the program puts in characters at the head pointer and the interrupt driven output removes them at the tail pointer TIME UP FRONT Serial support routines may seen like a small matter in the scope of a much larger program However done incorrectly they can bring a whole system down due to an unrediable serial port Taking some time up front to ensure solid serial port operation will certainly pay off late LJ
121. h Extended Data Status On Status Off Status Request e denotes not supported by any current X 10 module e denotes supported only by the RR501 RF gateway module Tabb I X 10 transmissions ahvavs contain a housecods and a function wde The function code either selects a particular module or invokes some acton The X 10 system can handle up to 256 unique module addresses but the manual controllers marketed by the company can deal with only eight or sixteen of those at a time If you have more than sixteen modules in your house putting then under computer control is the next logical step in making them easier to use Although some companies developed X 10 products in the past that used a microcontroller there was no clean way to connect the controller and the power line This void limited product development to those compa nies who could afford UL and FCC testing of such interfaces Several years ago X 10 finally eliminated this bottleneck with the introduction of the PL513 computer interface module The PL5 13 provides the designer with an optoisolated interface to the power line A signal coming from the module tells the computer when each power line zero crossing occurs Additionally a signal to the module controls when the 120 kHz carrier is applied to the power line The user is the one who must send properly formatted data to the PL513 in synchronization with the zero cross ings See Power LineBa
122. h line In addition to the OSD functions the 87C054 also performs network interfacing and protocol tasks This microcontroller has plenty of perfor mance bandwidth because the OSD logic is self refreshing and independent of the MCU core VIDEO SIGNAL SWITCHING The JRC2244 video switch U2 contains three video inputs two of which are used in this application One of these inputs VIN1 is capaci tively coupled to the OSD video signal This signal is the 87C054 s RGB data after encoding into baseband video ucc R19 82k 1 YSA 74HcT221 C24 1000pFf Re use Z4HCTOO 4 R22 R23 100k 3 9k D1 1N4148 R24 L c22 cs cee cei a See 2 ee 470pF E20pF 0 luF R21 La L3 3302 2 2uH2 2 2uH vcc Figure 4c n order to properly overlay colors onto a PAL signal you must amp now whether you re on an odd oran even field so extra circuitry must be included on the board to support PAL 32 Bit RISC and Video Display Module for Embedded Graphic Display Applications The Pixel Press is a 3 1 x 5 1 inch module used to control video image generation and replace personal computers PCs in embedded applications When compared to a 386 PC the Pixel Press not only provides superior resolution and response but it does so at a fraction of the cost size and power requirements 5V at 800ma Further the Pixel Press includes the watchdog timer and voltage supervisor required in embedded processors but not found
123. haracter data or original video information The video clock osdillator pro vides timing for the character dots In most applications this oscillator is simply an LC tank circuit connected to the VCLK pins The frequency controls the character width One nice feature is that the video clock is killed at the leading edge of HSYNC and restarted at the trailing edge of HSYNC which causes the video clock to start in the same phase on every line ensuring the dots align vertically from one scan line to the next The character font stores the binary pattern for the individual characters Charac and 18 scan lines high The OSDRAM to be displayed on the screen along with certain at tribute data pertain ing to those charac ters Once a charac ter has been written to the OSD no further CPU interven tion is required to refresh the screen Many OSD architectures have been developed over the years for use in the consumer television market Almost all of them have required fixed character row formats limiting the designer s flexibility in designing video menus and screens The 87C054 was designed to avoid such constraints and there are no architectural limits on the number of characters in a row of text or the number of rows of text to a screen There are physical limits imposed by the dot clock frequency and the scan rate of course TheHSTART and VSTART pa rameters in the OSORG on screen origin register d
124. hart a course to success with ViewTask 800 358 7087 USA 503 641 8446 FAX 503 6442413 14215 NW Science Park Drive Portland OR 97229 U S SOFTWARE 1992 US Software is a registered trademark and ViewTask is a trademark of United States Software Corporation 166 See us at the Embedded Systems Conference Booth 738 The Computer Applications J ournal Issue 29 October November 1992 91 DIAL IT 0N No one to turn your computer on Dial It Onturns on your computer via the telephone Security ring sequence lets only you turn on your computer 6 Outlets at 10 AMPs each 6 Rocker lighted switches e Surge protection for both the AC and phone line Fits nicely between the computer and monitor Need to inferface your electronic equipmenf to PC P Module saves fhe O s of and interfaces your electronic equipment fo any IBM PC compatible through the parallel port Addresses 256 16 bit or 512 8 bit read write registers through the parallel port e Microsoft and Trubo C software drivers Turbo Pascal software driver e Includes the hardware software design examples e No power supply needed e Enclosed in small and sturdy plastic box DROM128K EPROM EMULATOR 92 349 00 Eliminate wasting fime burning EPROM withDROM128K during the development cycle Plug DROM128K in place of EPROM and download your code as many times as you need through the parallel port Emulates two 2764 through 27010 1 meg Dual R
125. has been stored the beginning character of the message is checked to see whether the message includes a checksum If the message does not contain a checksum the packet is assumed to be valid and the contents of the packet are pro cessed If a checksum is included then the v ERI FY routine is called to per form a checksum calculation on the packet If the checksum matches the packet is processed otherwise it is ignored and return to waiting for the next network message My original plans for handling network checksums included a checksum generator for sending network responses and a checksum checker for received messages H ow ever when flowcharted the needs of both routines found that an awful lot of the logic was common to both went back and looked at the sugges tions that Ed Nisley had provided for handling the checksums and under stand now why he made those sugges tions My v ER FY routine s logic is based on Ed s previous work The VERIFY routine performs two functions First it takes the checksum digits in the packet converts them to binary numbers and stores then in temporary variables Next the checksum digits are replaced with ASCII zeros and the checksum of the string is calculated If the checksum matches the error flag C H K ERR is Cleared otherwise it is set The checksum that was calculated is converted to ASCII and stuffed into the checksum digits position replac ing the ASCII ze
126. hat interrupts are on 4 Turn on the serial O inter rupts All the code to do steps 1 through 4 isin the routines er_ init0 Separate sections in this routine handle the setup of COM and COM2 These sections set the unique constants in the COM data structure and set the different interrupt vectors If you add another port you will have to rewrite this routine adding sections to support your hardware Listing 2 shows the code to do all four steps Note that you must turn the interrupts off before you do anything This way you won t be changing a vector while the system processor is trying to use it The interrupts are turned off and the vectors are defined by Quick C other C compilers will have similar but different conventions Steps 3 and 4 are then completed and the interrupts are turned back on In the above section notice that you turned on the interrupts for serial input but not for serial output This omission was made simply because there isn t any data to output yet thus the 8250 transmit buffer is empty The 8250 is set to generate a transmit interrupt on an empty transmit buffer so that is not what you want now The code to transmit data putser turns on the interrupt whenever new data is to be sent and turns the interrupt off when there is no more Shutting down the serial 1 O system is just the reverse of starting it The most important functions are turning off the serial interrupt and rem
127. hat l d like to read While that approach might work for a limited time would be overly egocentric to assume that my interests always satisfy the majority In fact can already sense a narrower focus of my technical interests Perhaps converting from straight technical responsibility to more managerial duties has dulled the wit somewhat Instead of relying solely on Ken s or my personal interests to continue to stimulate the editorial direction of CA we instead resort to asking you that question periodically On a regular basis we send 4 6 page questionnaires called Editorial Surveys to randomly selected groups of readers The results of these surveys help us fine tune our editorial direction as well as identify emerging interests These surveys have always had an astonishingly high rate of return and we are continually encouraged by the comments we receive Just in case you don t know who you are let me tell you The CAJ reader is a doer with instinctive entrepreneurial talents Either as an individual consultant or part of a large company project group the CAJ reader views his or her success as providing real solutions to real world problems The latest survey results show that the average CA reader is both technical and professional About 74 of CAJ readers say they are involved with microcontroller applications in their work but with two thirds of the audience evenly divided between t 50 and 10 000 employee companies n
128. hat you passed through all the basic colors in the visible spectrum Saturation Saturation defines the pureness of a hue for a given level of lightness Conceptually saturation is the radial coordinate in the model The larger the radial coordinate the purer the color Colors of low saturation tend to be soft or pastel and fully saturated colors can be harsh depend ing upon their lightness A lack of saturation defines the grayness of a hue Note that grayness covers all levels of gray from total black to pure white Any hue at zero saturation will be pure gray Whether the gray is black white or somewhere in between will depend on the light ness A good example of an unsatur ated color is pink which is somewhere between pure red and white Lightness Lightness is how bright or dark a color is as the name implies It is the vertical axis of the model Due to the modal s double cone structure the maximum saturation level depends on lightness This level varies from 1 at the equator to 0 at the poles A lightness of 0 or 1 will havea maximum saturation of 0 because Figun The HLS mode can be conceptualized in three dimensions asa pair of cones Hue proceeds anwnd the cones Lightness runs in the vertical direction and Saturation extends radial amp from the center and depends to some degree on the Lightness Tektronix Inc those values correspond to black or white while a hue can be fully saturated at the equ
129. he current overflow count restarts the timer and checks for the end of the buffer If all goes well it returns to the top of the loop and waits for the next edge I ve listed the duration of each instruction in the three loops to show the overhead involved Ample time is available after each edge to record the data because the IR pulses are a few hundred microseconds long However the code will eventually have to account for the time that transpires while the timer is stopped to record each time stamp as well as the average loop time overhead Issue 29 October November 1992 67 SIGNAL SQUASHING The only hardware change required for the MCIR Link function is to substitute a 32K byte RAM for the 8K unit on the IR Link board The MCIR Link code uses the lower 8K for variables capture and replay buffers and so forth leaving 24K bytes for the remote control IR signals Simple division says that if typical signals have 100 pulses at 6 bytes per pulse then that big RAM has room for about 40 signals Obviously some data compression is in order While deploying an armada of signal processing algorithms against the captured signals would be nice my plans were straitjacketed by three simple constraints Whatever method picked must work reasonably well for all remotes using modulated IR not take forever to get working and not displace any IR Link functions knew that the only practical way to produce accurate arbitrary
130. he time elapsed between pulse injection and the detection of the return pulse is then used to compute the round trip distance to the cable discontinuity What may be obvious at this point is if the pulse is not reflected no discontinuity exists in the cable The mystery is why any portion of the wave reflects at all and upon being reflected why the electromagnetic wave may undergo a phase change Though the TDR s injected pulse is by no means sinusoidal Fourier analysis shows it is composed of sinusoids For the following discus sion it is easier to assume the travel ing wave is purely sinusoidal and of some particular frequency If the transmission line is terminated and assumed to be lossless then the load Issue 29 October November 1992 23 Sw3 BUZZER D DAC AB D Ai DISPLAY RS Figure 2 A n 87C51 nms the TDR A 2 channel DAC is used b control the LCD display contrast aNd tO create a variable offset for the measurement circuits The power control circuitry automatically powers the system up at the press of a bution and powers if down after a fixed period of inactivity Z1 Must also equal V I of the incident waveform Thus using the equation developed for V and 7 the following relationships can be established V Acit 2h A elet 3 7 Zo Ae 2z E A eit z Don t let the complex exponentials distract you They are in conjunction with the parameter A part of the characterization of th
131. head and scan the entire keyboard which is not a problem because don t do the actual scan from an interrupt service routine You could do the scan from an interrupt but if you weren t careful you might end up hogging the system for perhaps 100 ps or more at a shot If interrupt level processing is desirable then the piecemeal approach makes more sense but you will have to maintain state information on where you are in the scanning process adding to the overhead load The Computer Applications Joumal THE GENERIC KEYBOARD DRIVER The idea behind the way imple ment key scanning consists of invok ing a callable routine at 20 ms inter vals which is usually referenced to an interrupt driven timebase A minimal amount of state information must be retained so the process can progress in a seemingly unbroken fashion because the operation is discontinuous Fun damentally the routine checks all the keys then determines whether a valid key is available using local and global variables On completion an exit code indicates if a key code is being re turned to the caller Although uncomplicated enough in principal to begin with you can further simplify the keyboard scan algorithm by breaking it up into three sections As l II show viewing the process thus allows adapting the general concept for use with various hardware schemes describe the three components of the key scanning procedure as the entry the contact scann
132. hips and systems can also be rejuve nated DANCING AS FAST AS I CAN The Z80 and its follow on the Z80 180 a slightly modified HD64 180 certainly qualify as some of the most popular chips of all time Neverthe less these parts are starting to show their age Now Zilog has come to the rescue with the new Z8S180 Though fully plug compatible with the existing 180 the S180 has a number of new features The S stands for the static design of the chip The primary benefit of static as opposed to dynamic designs The Computer Applications ournal is you can arbitrarily run the clock slowly and indeed stop it altogether This ability to stop the clock is exploited with the new power down modes IDLE and STANDBY which supplement the SLEEP JO STOP and SYSTEM STOP modes of the original 180 Figure 1 The STANDBY mode 10 pA cuts power consumption dramatically when compared to the previous lowest power mode SYSTEM STOP 17 5 mA making the S 180 far more suitable for battery powered applications A neat addition but nobody is going to rave about a new chip that runs slower than ever However the new static CMOS design offers another benefit the S180 runs at up to 20 MHz twice as fast as the regular 180 Longtime readers know I m a big believer in clock rate when boosting CPU performance Let others dabble with the complexities of superscalar superpipeline and various other super duper trick
133. ice inverted bell curve distribution I d conclude that they seek out CAJas a pure technical resource The fact that 92 save every issue supports this conclusion One fact unchanged in five years is that readers prioritized interfacing computer control and home automation and security as their dominant interests There is also a broad range of secondary curiosities but these seem to share equal preference The truly technical community gains as much relevant resource information from an article on geopositioning as it does on analog sensor interfacing No effete snobs around here One remarkable statistic probably attributable to a professional audience with money is that the average reader has more than three personal computers And while these cover the spectrum as far as processors and brands 94 have at least one IBM PC compatible From an editorial point of view this makes PC software support of published projects seem logical won t bore you with all the other statistics but will say that we continue to learn at the same time we reconfirm our prime directive Most of all we recognize that like ourselves you are a demanding breed As a successful technical professional called upon to make real world decisions resource material quality is of ultimate importance Your unprec edented support and our continued growth suggest that we ve met that test Our ensuing goal is to try to present more of it Dore 1112 lssue 29 October Novemb
134. ich is done by adding another linear function such as f 1 for x gt 1 6 However limiting f to negative values with a MIN function and letting BLUE decrease according to f1 is just as easy Similarly a MAX function can be used to prevent BLUE from becoming negative for x gt 1 3 The analytic form for the function BLUE over the entire range of the hue coordinate as well as the functions for GREEN and RED areas follows Blue MAX 2 0 MN 4A 0 Max 0 MIN 3 0 Green X MIn A 0 MIN 0 Max 0 Red MAX 2 0 MIN 2 0 Ax MIN S 0 Listing 1 shows the C code for the functions BLUE GREEN and RED named mag_blue mag_green and ma g_red respectively The values returned are always betwem 0 and 1 Listing 2 contains the C code for the set pa 1 which transforms HLS values to RGB and then calls the video BIOS to load VGA registers with the RGB values set pa receives as its argument values for hue lightness saturation and the register whose color you are going to define For VGA 640 x 480 resolution only 16 colors may be displayed 52 issue 29 October November 1992 1 3 Figure 2 By laying out hue in one dimension it s possible to begin bseehe relationship between hue and RGB Each of the RGB colors forms a trapazoid that partally overlaps he other colors simultaneously which means only register values O 15 are legal set
135. in PCs Included in each Pixel Press is a 32 Bit RISC Processor 86C010 from VLSI Technology 512K byte frame buffer 256K byte processor DRAM EPROM voltage supervisor and watch dog timer A parallel interface is used for high sneed command and data transfer while a RS 232 TTLJLevel port is used for debug or remote input The parallel port operates in both a master and slave mode and the serial debug port can be configured for connection to a PC compatible keyboard In slave mode BUSY and ACK signals are generated to mimic an IBM or Centronics printer Salve mode also supports direct connection to a micro processor bus Master mode allows the RISC to read and write up to 64 external IO ports Model a Serial Applied Data Systems Inc 409A East Preston Street Baltimore Maryland 21202 Made in USA 1 800 541 2003 410 576 0335 410 576 0338 FAX The Pixel Press Module mechanically mounts to either a user printed circuit board PCB or chassis PCB mounting is accomplished by soldering the Pixel Press 0 025 square posts directly into the user PCB Chassis mounting makes use of four 4x40 threaded mounting holes Our other Fine Products Our 24 BIT PARALLEL IO card with double buffered TTL IO features pro grammable direction control amp The EASYON SMART EXTENDER is so unique we were granted US Patent No 5 047 708 Allows aboard to be plugged be Ground between Signal design for into a PC XT AT
136. ing and the processing sections Additionally you must provide a separate initialization routine to set up the global variables to their default state on power up before key scanning can begin Local working storage is allocated for the dements called KEY COUNTER KEY NUMBER andKEY HIT The entry code simply consists of clearing KEY _ COUNTER andKEY HIT tozero KEY_ NUMB E R may be left indeterminate The contact scanning procedure consists of a repetitive loop that checks the state of each key You will best understand the function of the loop from a quick definition of the local variables KEY COUNTER a counter that increments each time a key is checked KEY _ H IT a counter that is increnented each time a key Cosure is detected and KEY NUMBER a register to which the KEY COUNTER is copied when a key closure is detected The loop terminates when KEY_ COUNTER reaches its terminal value indicating all keys have been checked At the conclusion of the contact scanning loop control is passed to the process code where a decision is made as to whether a valid key was been Issue 29 October November 1992 89 LCR Hz dBm True RMS o M Ee pomno ng M TTT 4 PAA BATMAN RELATIV Ks anon oF wi 2 EN R AK 40nF Ly 4004 aoe fon Auf OOK Cy auto power off LCR Hz dBm COM V Q H2 Cx i UNUSED N A 10A MAX KELVIN TRUE RMS s Model 94 1 ACCURACY onbe voltages TRUE RMS Pus MAX MIN
137. is The Engineer s Programmer BPwceosrsems 10681 Haddington e Houston TX 77043 3239 713 461 9430 FAX 713 461 7413 1991 BP Microsystems Inc 149 76 Issue 29 October November 1992 60 IF G lt gt 57H AND G lt gt 77H THEN 180 70 REM Write Routine REM Rr 80 INPUT Write which house code 0 15 V 9OI1F V lt 0 0R V gt 15 THEN 80 100 GOSUB 1000 110 INPUT Write which function code 0 31 V 120 IF V lt 0 0R V gt 31 THEN 110 130 GOSUB 1000 140 INPUT Repeat code how many times 150 LF V lt 1 0R V gt 30 THEN 140 160 GOSUB 1000 170 GOTO 30 180 REM Read Routine 190 GOSUB 2000 200 IF V gt 15 THEN PRINT New 210 PRINT 220 GOSUB 2000 ELSE PRINT House Code V and 15 1 30 7 V Ol d 230 PRINT Function Code V and 31 240 GOTO 30 1000 1010 1020 1030 REM Wite a Value 1050 RETURN 2000 2010 REM Read a Value 2030 IF PORT1 AND 80H 80H THEN 1010 REM Wait for RDY to PORT1 PORT1 0R 60H AND OEOH OR V REM Set DIR CS IF PORTI AND 80H lt gt 80H THEN 1030 1040 PORT1 PORT1 AND 9FH REM Clear IF PORT1 AND 80H 80H THEN 2010 REM Wait for RDY to 2020 PORT1 PORT1 0R OBFH REM Set DIR IF PORT1 AND 80H lt gt 80H THEN 2030 REM Wait for drop DATA REM Wair for RDY to rise DIR and CS drop inputs rise Clear CS Data as RDY to 2040 V PORT1 AND 1FH REM Get the lower five bits 2050 PORTI PORT1 AND 9FH REM Drop CS 2060 RETURN
138. istor to be connected to J2 The output of the Q1 buffer amplifier feeds the sync separa tor the video switch and the chroma subcarrier regenerator circuits SYNC SEPARATION The sync separator consists of U6 a TDA4820T Philips sync separator The video signal is coupled into the TDA4820T through capacitor C 14 where it is amplified with a gain of 15 The black level clamping voltage is stored in capacitor C14 From the stored black level voltage and the peak sync voltage the 50 value of the peak sync voltage is generated and stored in capacitor C15 A slicing level control circuit ensures a constant 50 44 Issue 29 October November 1992 peak sync value regardless of the picture content amplitude provided the sync pulse amplitude is between 50 mV and 500 mV A comparator in the composite sync slicing stage compares the amplified video signal with the DC voltage derived from the 50 peak sync voltage producing the composite sync output Vertical slicing circuits compare the composite sync signal with a DC level equal to 40 of the peak sync signal producing the vertical sync output The reduced vertical slicing level ensures more energy for the vertical pulse integra tion The slope is double integrated to eliminate the effects of interference caused by noise or line reflections The value of resistor R10 sets the vertical integration delay time The outputs of the sync separator are positive going signals with peak am
139. it s 1 3 or 55 ns access time for 165 ns cycle time Also the discrepancy becomes much worse as the cycle time shrinks unless you deal with fixed propagation delays i e pokey TTL What s clear is that the LS138 is the main bottleneck typically taking 21 ns to drive the CS output after MREQ input checked into an ALS138 ALS is a more modem and faster technology than LS and discov ered could buy the 10 ns needed for about 50 cents Finally I m 18 432 with zero wait states and like it L Tom Cantrell has been in Silicon Valley for more than ten years working on chip board and systems design and marketing He can be reached at 510 657 0264 or by fax at 510 657 5441 CONTACT Zilog Inc 210 E Hacienda Ave Campbell CA 95008 6600 408 370 8000 The 100 piece price for the 20 MHz Z8S180 PLCC is 17 86 WaferScale Integration Inc 47280 Kato Rd Fremont CA 94538 7333 5 10 656 5400 The 100 piece price for the 55 ns WS57C256F 32K x 8 EPROM is 11 70 425 Very Useful 426 Moderately Useful 427 Not Useful 68HCl 1 Single Board Computer 65 Singles Features 8051 based Siemens 80535 amp 4 Parallel Ports 1 Serial Port A D Timers Watchdog 3 Memory Sockets 64K Addressing 8K RAM installed RS 232 Conversion Board sbe is 100x 100mm Approx 4 x4 CALL NOW NEW MICROS INC 1601 Chalk Hill Road Dallas Texas 75212 Tel 214 339 2204
140. ith a fast easy software version on DOS 5 25 diskettes Included are separate volumes on setup controller cards and drive settings The information includes everything service professionals need to know about switch settings cable locations configuration param eters power specifications error codes and interface basics for ST506 412 SCSI ESDI IDE floppy and more Clear drawings detail switch settings and cable connec tions for both drives and controller cards Also included are BIOS tables and a complete index of manufacturers with contact information The 595 Solution to 8051 System Development PDK5I SIBFC H microcontroller board 8052AH BASIC CPU with 16K RAM BASIC interpreter source on disk SIBEC HI hardware manual with schematic e Monitor debugger ROM plus manual Monitor debugger hardcopy source listing UL fisted 5V power supply Programming power supply adjustable from 4V to 26V e KFRMIT communications program SXA51 8051 8052 cross assembler BTK52 BASIC programmers toolkit with tutorial 160 page BASIC Programming Manual by Systronics RS232 cable PDK5I tutorial The PDKSiis a fully integrated hardware firmware and software system designed to Help you develop your products quickly and cost effectively All you need to use the PDK51 is an IBM PC XT AT or compatible we supply the rest PDK51 PLUS includes everything in the PDK51 plus Vers 3 of ou po
141. itted on one RF carrier The answer they came up with was to modulate one of the signals B Y with an RF carrier The other signal R Y was to be modulated with the same RF carrier but the carrier would be shifted by 90 When the outputs of the two modulato s are added together the result is the vector sum of the two signals containing both an amplitude and a direction phase angle See Figure 1 We now havea single signal that contains all of the color information The TV receiver needs just one more piece of information to demodulate this signal It needs a reference for the carrier used for the modulation that is the receiver needs to know where 0 of the color carrier is in video this color carrier is referred to as the chroma subcarrier In order to give this reference to the receiver a small v2 Local Video JRC2244 LocaL EXTUID _ cs External Video Tour RS 42 4 Sl vec ry SW SPDT it f vec i 10uF aes 1P3 5 3853 4 VINI UCC Pe s VINZ VOUT C3 VIN3Z SW 1 GND SwW2 v3 87CO54N42 P3 7 PO 7TOAC PO 17 PML PO 27PWM2 ro PO 3 PWM3 Hips P3 3 INTO PO 4 PuIM4 P3 2 TO PO S PUMS P3 1 INT1 PO 6 PWME P3 0 PO 7 PuM7 RST P1 07ADIO XTAL2 P1 17ADI1 AI XTALL P1 27ADIZ lt 1 BF P1 3 PWMO P2 7 ay UCLK2 P2 8 P2 5 VCLK1 VCTRL VID2 P2 4 42 VIDI PP 3 VIDO P2 2 VSS P2 1 P2 B HEADER 3 Figure 4a The JRC2244 switches between he
142. lector an RS 232 serial channel and a sensor supply voltage of 12 VDC at 200 mA The entire unit is packaged in a 2 75 x 3 DIN rail compatible case with captive screw termi nals A board level version PPLC BRD extends the I O to eight inputs eight outputs and four analog inputs Both units sell for 239 in single quantities DIP Industrial Products P O Box 9550 Moreno Valley CA 92552 714 924 1730 Fax 714 924 3359 503 Issue 29 October November 1992 The Computer Applications Joumal PC BASED MOTION CONTROLLER MicroKinetics Corpora tion has introduced Quickstep a new stepper motor controller containing on board translators and power drivers for up to three axes all on one card It is designed for cost sensitive applications that do not require very high stepping speeds and where the convenience of having the indexers and drivers on one card is important The Quickstep plugs directly into any 8 or 16 bit ISA bus IBM PC or compatible eliminating the need for an external enclosure Features include programmable acceleration and deceleration automatic overtemperature protection end of travel detection on all axes two auxiliary outputs per card and a shield open interrupt The Quickstep operates interac tively no uploading or downloading of programs is required It provides keyboard control of such functions as J og Pause Abort and so forth and drives motors requiring up to 0 9 amps
143. lers Intel Microsoft Borland WATCOM Zortech Metaware and more FAST and MultTask are trademarks Of us 1992 US Software gere Software Corporanon All trademarks belong to their repective owners The Computer Applications Solutions for 80386 486 PROTECTED MODE 80x86 amp V Series Z80 180 64180 8085 68xxx 68HC16 68HC11 6801 6809 805 1 80 196 i960 R3000 SPARC and more Call for free information diskettes today PHONE 503 641 8446 FAX 503 644 2413 USA TOLL FREE 800 356 7097 14215 NW Science Park Drive Portland OR 97229 US SOFTWARE See us atthe Embedded Systems Conference Booth X738 Joumal Issue 29 October November 1992 43 External Video 100uF U6 TOA4820T igure 4b The TDA4820T sync separator provides the processor with horizontal and vertical sync signals phase as the color burst on the original video input signal Once you get the OSD informa tion in the form just described you can switch between this OSD video and the original input video to produce the final output THE TV LINK HARDWARE SOLUTION Figure 3 shows a block diagram of the TV Link while Figure 4 shows the schematic Referring to the schematic the original input video connects to J2 and is AC coupled into buffer amplifier Q1 This amplifier provides load isolation between the video signal source and the drcuits on the TV Link board JP4 is a jumper allowing for a 75 ohm termination res
144. lse ON and OFF times 10 Number of pulses in one byte format Pulse ON and OFF times 0038 and EDEA End markers two zero bytes wrap flag count in the force exit on timeout R3 R2 RawLp exist by definition Most pulses are shorter than 2 2 ms so much of the data can be squashed into runs of single byte times decided to work with pulses rather than individual times If ether time value required two bytes assigned four bytes to the pulse If both could fit into single bytes the pair took up only two bytes of stored data In practice this method works reasonably well but of course there are some remotes that pair short pulses with long ddays Figure 3 shows the final data for an actual captured IR signal The record contains four dements the record number the overall pulse count four bytes for the lead in pulse and runs of one and two byte pulse times preceded by a one byte pulse count for each run The counts may be zero if the data requires more than 255 03CO ON 01 F2 OFF 16 32 bytes total final delay is quite long Figure 3 The firmware stores IR data using run length compression b encode time valves in he least number of bytes This record was captured from a remote controlthatuses a bng leadin pulse followed ty several shorter pulses The Computer Applications Joumal Real Time Devices Accessing the Analog World Exciting New Products AD1200
145. m Circuit Cellar Inc is prohibited NANA 29 12 Planting Geraniums by Robot Build an MC68HC11 based 2 D Sensor by Brian Farmer 22 The Design of a Time Domain Reflectometer by Brian Kenner and J ohn Wettroth 3 4 Serial I O on the IBM PC by Jim Schimpf JALANAN AON Embedded Graphics amp Video Add Text Overlay to Any Video Display by Bill Houghton The Virtues of the Hue Lightness Saturation Color Model by James R Furlong 61 Driving Multiple VGA Monitors by Michael Swartzendruber Practical Algorithms j ohn Dybowski The Middle Ground Negotiating a Keyboard Interface ym Editor s INK Ken Davidson A Look at Next Year ConnecTime Excerpts from the Circuit Cellar BBS conducted by Ken Davidson W New Product News edited by Harv Weiner GLA Firmware Furnace Ed Nisley Steve s Own INK Steve Ciarcia Extending Your Control The HCS Il MCIR Link Let Me Tell You About Yourself F From the Bench eff Bachiochi ya Advertiser s Index X 10 Interfacing with PLIX 10m Silicon Update Tom Cantrell I m 18 432 and Like It The Computer Applications Journal Issue 29 October November 1992 6 UNIVERSAL DEVICE PROGRAMMER The first device programmer in produc tion offering a single universal PLCC socket has been announced by B amp C Microsystens Inc The new socket technol ogy of the Proteus104 accommodates any PLCC device from 20 to 84 pins reducing PC board traces and capaci tance on the pr
146. n issue 25 of the Computer Applications Journal Steve Ken and introduced the Home Control System Il HCS II The system is based on a Supervisory Controller which handles all the grisly scheduling and oversees the whole system and networkable Link modules which expand the system I O by adding digital I O ports LCD display X 10 power line control and more I ve been steadily covering all those network modules in the last few issues Back in issue 26 s Firmware Furnace entitled Infrared Home Control Gateway Steve and presented the IR Link module as a command and control gateway into HCS II It received and transmitted infrared signals in the 9 bit Motorola MC145030 format and included enough features to implement IR badges people tracking and so forth and so on Refer to that issue for a complete IR Link schematic and discussion of the hardware and firmware dump MCIR data from RAM to HEX w base addr receive MCIR data from HEX to RAM send MCIR signal n 1 999 RAM 1001 1999 EPROM train new MCIR code store in RAM as n I 999 set duty cycle correction factor 0 255 clear MCIR data from RAM Figure The MC R Link firmware adds these commands to the R Link s repertoire Unlike the other Link modules the new H commands transfer intel hex data directly between the hast computer and the MC R Link s RAM However sending commands to the HCS control program with an IR remote wasn t
147. n the world it was done the way it was A long time ago e For Quality E et P O Box 490 Rockpo utside U S call 202 ee See us at the Embedded 42 Issue 29 October November 1992 Call today 1 800 448 8508 126 The Computer Applications J ournal before Americans had ever heard the names of Japanese TV makers RCA research labs were developing color televeision One of the requirenents imposed on designers by the FCC was that the broadcast signal needed to be compatible with existing black and white TV sets and had to be contained within the same bandwidth as a B W signal Such requirements meant that some component of the signal had to contain overall brightness informa tion which is the main reason why they could not simply transmit sepa rate R G and B channds within the video bandwidth allowed To make a very long story short the engineers involved decided that the scene bright ness which they called Y or lumi nance could be described by the relationship Y 0 59G 0 3R 0 1 1B Someone observed that if they took two copies of the luminance signal and subtracted one copy from one of the colors say RED and did the same with a different color say BLUR the result would be two signals that contained all of the information needed to represent color These resultant signals R Y and B Y are the color difference signals Now that you have two signals how can they be transm
148. nal at the output of our circuit One solution is to decode the input video into separate red green blue HSYNC and VSYNC signals Then you could perform the multi plexing between video information and character data in RGB format The resultant signals could then be en coded back into baseband video If Picture Information Horizontal Sync Figure 2 A typical line of NTSC video consists of an initial horizontal sync pulse followed by a short color burst signal hen he actual picture information The Computer Applications J ournal Issue 29 October November 1992 41 Viio Switch Color Encoder and Figure 3 A the core of the TV Link is the Signetics 87C054 microcontroller The unit supports boh RS 232 and RS 485 communications with a host computer there were other reasons for the con version into RGB such a conversion would be the way to go However the process of converting to RGB and then converting back to video introduces some distortion that could be visible on the screen Another solution is to find a way to encode the RGB data from the OSD microcontroller into video Then you can simply switch between the two sources Sound simple The situation gets a little more complex when you consider the issues of making the characters appear with the proper color in NTSC Reviewing how color is encoded in NTSC is in order COLOR TELEVISION When you first look at video you often wonder why i
149. ned Then the robot arm had to make the appropriate moves to align the end of the sten with the hole in the peat plug accu rately Type LVDT Schlumberger Ind ACR 15 Type Ultrasonic Polaroid Corp Design Kit Contaq Tech UDM RMU Ultrasonic Arrays DMS 100 Cosense ML 1 01 Type Optoelectronic Banner Engineering MP 6 Banner Engineering SBF5 w IR2 53S Frost Controls Keyence Edge Sensing Sensor 2 D LS 3033 amp LS 3100 Range Resolution 0 030 m o0 0 27 m 10 7 m 0 003 m 3 m 0 15 m 9 14m 0 0002 m 0 005 m 6 61 m 0 0002 m 0 02 m 2 74 m 0 00005 m 3 05 m 0 013 m 0 025 m oo 0 025 m 0 0025 m 0 03 m 0 000002 m eo Analog output resolution primarily limited by measuring device Table 1 Numerous sensors are available that might have helped in this project but none fit the project criteria The Computer Applications Joumal Issue 29 October November 1992 13 RS 232 Conditioner XC68HC711E9FS Microcontroller Analog Signal Conditioner 5V when light path is locked 80 Photo transistors Figure 2 T7he extemal robot controller starts the whole measurement process Results may be optionally displayed on a terminal screen Dra RaAntral Www wl tut Wwe Introducing the Most Expandable 3 1 2 Board Available MCU 31 2 from 149 95 On Board Options Include 16 Channels 10 bit A D 14ys w S H Dallas 1287 RTC Flexible mem config s RAM 8 32KB ROM 8 16 32 64 KB RS 232 or 485 jumper
150. network and is occasionally polled by a PC via an RS 232 connec tion Use your imagination L Brian Kennez is a project engineer at Science Applications in San Diego Calif He has developed several fixed and hand held microcontroller based instruments used in vibration and radiation monitoring and analysis John Wettzoth is employed as the Chief Engineer of Science Applica tions Military Products Division in San Diego Calif He also owns Tzavtech a sole proprietorship involved in electronic instrumentation development and HP 48 calculator data acquisition 404 Very Useful 405 Moderately Useful 406 Not Useful ROM Borland or Microsoft C Complete 80x86 ROM development kit Whether you use Borland C or Microsoft C to develop for ROM C_thru ROM will help speed your projects to completion This complete ROM development package is the only product that gives you all the tools you need for easy Place your Microsoft or Borland C code in to ROM with the C_thru_ROM complete ROM development kit pomp Bi development of 80x86 ROM code on your PC C_thru ROM includes ROMable startup code floating point support a ROMable library that includes printf malloc free etc and a
151. ngineering Graduate program with a teaching 401 Very Useful 402 Moderately Useful 403 Not Useful The Quick Way into Embedded Software Development BIFF Boee B FF 0808 FFFF i CS 9 Rs 7 amp Oe Language IDEAL brings together all of the tools used to develop software for Single Board Computers SBC and blends them into a menu driver windowed environment that speeds your development process Automates the Compile Assemble Link Download Cycle e Works with any Compiler Assembler Linker etc Use the built in Editor or link to your own Editor it s easy Great for BASIC and FORTH interpreters too e Interrupt driven serial communications to the SBC Swaps memory to make room for the largest tools Resizable Zoomable Windows for Editing Browsing and Target Communications Fully integrated mouse and keyboard control In use for 2 years at Major Universities and Corporations Requires PC XT AT wi512K 30 day Money Back Guarantee Demo Available on BBS r creative Phone 415 494 2363 applications Compuserve 74 156 1207 BIX ecarryer engineering inc F 0 Box 9524 Stanford CA 94309 BBS 415 494 8463 1 The Computer Applications Journal Issue 29 October November 1992 21 OObSbGu Pa FEATURE ARTICLE Brian Kenner amp John Wettroth The Design of a Time Domain Reflectometer 22 As anyone who s tried to track down an elusive network cabling problem
152. nitialization and ring buffers The initialization and shutdown code manipulates a whole range of hardware registers in the serial 1 O chip and interrupt controller of the PC Ring buffers are a useful concept and if you haven t used them in your code you should try them INITIALIZATION At thestart of the SERCOM code are a large number of defi nes Some 1 0 port using COM 9600 bps no parity a 1000 byte input buffer 8 data bits and a 100 byte output ser_init PORT_A BAUD_9600 1000 100 port not opened Failure to do this means the machine program run of these are the constants for the serial I O channes They give the address of the controller the interrupt it is using and the EOI command This last command tals the 8259 interrupt controller in the system that the interrupt is handled Other def ines give the names of the various registers in the serial I O chip and the interrupt controller Where did all these values come from Easiest are the serial device registers In original IBM PCs the the serial chip used was an Intel 8250 While most modern done PCs use highly integrated chips that include the serial ports instead of individual BOOLEAN putser char ch COM c int putsers char str COM c int getser COM c int getsers COM e int len char str BOOLEAN serhit COM c BOOLEAN serline COM c clean_ser COM c ser_dtr COM c ser_cts COM c 8250s they are accessed in
153. nly offered in Z88180 Note that the minimum recovery time can be achieved if INTERRUPT is used as the Recovery Source RESET Interrupts Programming RESET Interrupts RESET Interrupts BUSREQ RESET Interrupts BUSREQ Recovery Time Minimum 1 5 Clock 1 5 Clock 8 1 5 clock 2 1 5 Clock 2 1 5 Clock Figure 1 Due b ifs static design the 28S180 s dock oscillator can be stopped completely STANDBY for extreme amp low power consumption Say the RISC runs at 10 MHz and thus has a 100 ns bus cyde The current memory has 70 ns access time resulting in zero wait state operation Now Joe Naive User hears that a hot 16 MHz CPU is available and plugs one in ignoring messy details such as upgrading memory While the placebo effect may cause Joe to think his PC seems a little snappier the reality is the 16MHz CPU with its 66 6 ns bus cycle is going to need a wait state to work with the existing 70 ns memory The sad reality is that the hot CPU is running 33 slower 133 3 ns vs 100 ns than before the upgrade Fortunately the RISCer s need for speed has driven IC manufacturers to deliver ever faster memories In this era of 50 to 100 MHz CPU chips fast memories are de rigueur Unsure of which memories could scrounge at Zilog took the precau tion of tweaking the 180 board s BASIC EPROM to take advantage of the 180 s on chip wait state generator a great feature to inject the maximum number
154. nor does it take up any expansion slots It works on any PC DOS or 0S 2 Micro Channel or EISA Even Laptops Supports source level debug C and PL M and source level trace 4K trace buffer with advanced searching and filtering capabilities Now virtual memory and mouse support EN ance 7 Mela Corporation 129 See us at the Embedded Systems Conference Booth 604 The Computer Applications Journal Issue 29 October November 1992 47 A string Set HCS II network address to string Fx Execute special function Initialize screen Display on Display off Display color bars Wipe on Wipe off Set Px y high Clear Px y low Network response mode NO normal network interface no auto error or acknowledge responses N1 auto error and acknowledge response Query port x 0 Porto 1 Port 1 2 Port2 3 Port 3 Write to port x where nn two digit hex value 0 Porto 1 Port 1 2 Port 2 3 Port 3 Query register x returns two digit hex number 0 OSDT contents undefined 1 OSAT 2 OSCON 3 OSORG 4 OSMOD 5 Default char attribute 6 Default background space attr 7 Default NEWLINE attribute Write to register x for use from outside of a string of text writes to these registers from within a string should use the Wxnn command 0 OSDT 1 OSAT 2 OSCON 3 OSORG 4 OSMOD 5 Default char attribute 6 Default background space attr 7 Default NEWLINE attribute S
155. o JER ang information packet 9 FULL TECHNICAL SUPPORT Provided over the telephone by our staff EACH ORDER INCLUDES A FREE DISK WITH PROGRAMMING EXAMPLES IN BASIC C AND ASSEMBLY LANGUAGE A detailed technical reference manual is also included HIGH RELIABILITY engineered for continuous 24 hour industrial applications All ICs socketed Use with IBM and compatibles Tandy Apple Mac and most other computers with RS 232 or R 422 ports All standard baud rates and protocols may be used 50 to 19 200 baud Use our 800 number to order FREE INFORMATION PACKET Technical Information 614 464 4470 24 HOUR ORDER LINE 800 842 7714 Visa Mastercard American Express COD International amp Domestic FAX 614 464 9656 Use f r information technical support amp orders ELECTRONIC ENERGY CONTROL inc 360 South Fifth Street Suite 604 Columbus Ohio 43215 w112 Issue 29 October November 1992 1 Listing I continued NCB Loop throu LP1 CLR JSR LP2 LDAA STAA I NCB CMPB BNE CLR LDAA BPL LDAA STAA JSR LDAB DEX CPX BNE LDAA STAA J MP Subroutine WAITI LDAA WAIT1A SUBA BNE RTS NBS 10 Interface Card Record data count gh scan PORTB Next pair activated WAITI Wait a while 02 Next pair s condition xfered PORTB Record data count 8 One byte yet LP1 No go back for more PORTB Yes activate next pair SPSR SPDR full with 1 byte LP3 Keep looking for flag SPDR Load int
156. o on board RAM 0 X WAITI Wait a while 00 Reset data counter Count down 0000 All data in LP2 No go back for more 0C Yes SPI off Resets ends SPCR transfer And WARMST go back to Buffalo prompt gt Counter Count down Finished Distributed Control and provides gateway to network Data Acquisition RS 485 twisted pair PC Master Embedded controllers on a multidrop network Connectivity is implemented at low cost with a network designed by CIMETRICS TEcHNoLocy Our hardware software solution includes Microcontroller code PC XT AT interface card NSP protocol and application development software toolkit CIMETRICS tecunotocy the network solution for embedded controllers Mastercard 120 West State Street Ithaca New York 14850 Phone 607 273 5715 FAX 607 273 5712 x113 20 Issue 29 October November 1992 The Computer Applications Journal debugging and development with M otorola s BUFFALO program Listing 1 provides a demonstration program used to acquire and store data The code is implemented in the MCU s on board RAM as a subroutine while under control of the BUFFALO program with a warm start back into BUFFALO after program execution occurs Again acquired emitter receiver pair data is displayed on a PC s screen from on board RAM with a BUFFALO command The most important software detail involves the SCK and DATA timing SCK CLK speed is dependent on the photot
157. obot 22 The Design of a Time Domain Reflectometer FEATURE ARTICLE Brian Farmer Planting Geraniums 34 Serial I O on the IBM PC by Robot Build an MC68HC11 based 2 D Sensor What do you do when you need a sensor for an application nobody has thought of Build your own This unique sensor helps a robot prevent damage to delicate plant cuttings when handling them 12 Issue 29 October November 1992 The Computer Applications J ournal pposites attract so the saying goes Maybe it s true with people but definitely not with robots and flowers Even though the latter are about as opposite as can be they don t attract Matter of fact they are about as incompatible as you can get Robots are inclined towards uniformity and flowers are inherently diverse That s where my sensor comes in providing a necessary ingredient for a marriage that would otherwise never work or technically speaking assist ing a robotic system to accommodate nonuniformity Robotic systems aren t anything new They ve been around industry for years improving productivity and quality and doing many hazardous or uncomfortable tasks for workers For example the automotive and electron ics industries use robots to perform repetitive and precise tasks This form of automation is implemented in predictable and structured environ ments 1 with defined spatial configu rations Agricultural robotics venture
158. ogrammer header A 48 pin ZIF socket is mounted alongside for program ming 300 and 600 mil DIP devices The Prot us104 features fully overvolt age and overcurrent protected pin drivers full digital and analog capabilities for all pin drivers true system self calibra tion of all voltage sources and full diagnostics of all pin drivers a built in controller and timer with 250 ns resolution and state machine testing with rise and skew time of less than 10 ns The Prot us104 also features expandable pin driver boards allowing upgrades to any level within its 24 to 104 pin range An entry level version with 24 pin drivers and a 40 pin ZIF socket is the base configuration For production environments when programming MOS devices gang parallel modules replace the universal module and provide higher throughput to meet manufac turing needs by providing eight or sixteen ZIF sockets Also available is a memory card gang module supporting PCMCIA 2 0 Standard with sixteen sockets The programming and algorithm development environment is based on a single executable file with a built in editor and compiler for fast software develop ment and ease of use Semiconductor manufacturers use a powerful Algorithm DEvelopment Language ADEL in the creation of new device algorithms ADEL can also make changes to existing algorithms when revisions are required and can drastically reduce turn around time for the user of the devices An extensi
159. olenoid drivers time of day clock battery backed memory watchdog field wiring connectors up to 8 X 40 LCD with graphics and more Our 195 interactive Dynamic C makes serious software development easy You re only one phone call away from a total solution Z World Engineering 1724 Picasso Ave Davis CA 95616 916 757 3737 Fax 916 753 5141 Automatic Fax 916 753 0618 Call from your fax request catalog 18 177 The Computer Applications Joumal See us at the Embedded Systems Conference Booth 314 102 Issue X29 October November 1992 We invite you call the Circuit Cellar BBS and exchange messages and files with other Circuit Cellar readers It is available 24 hours a day and may be reached at 203 871 1988 Set your modem for 8 data bits 1 stop bit no parity and 300 1200 or 2400 bps ARTICLE SOFTWARE Software for the articles in this and past issues of The Computer Applications Journal may be downloaded from the Circuit Cellar BBS free of charge For those unable to download files the software is also available on one 360K IBM PC format disk for only 12 To order Software on Disk send check or money order to The Computer Applications Journal Software On Disk P O Box 772 Vernon CT 06066 or use your VISA or Mastercard and call 203 8752199 Be sure to specify the issue number of each disk you order Please add 3 for shipping outside the U S 431 Very Useful 432 Moderately Useful 433
160. ompatible with the full line of BCC bus expansion boards BASIC 52 s full floating point BASK is fast and efficient enough for the most complicated tasks while its cost effective design allows it to be considered for many new areas of implementation It can be used both for development and end use applications PROCESSOR B0CS2 BASIC Batit CMOS microcomputer sjumper Selactable conversion to 80031 80C32 functionality 8K bytes ROM full BASIC interpreter 256 bytes RAM three 16 bit counter imers 32 VO lines t1 MHz system dock 6 interrupts Memony sexpandable to 62K bytes five on board sockets sup Wo four 6264 8Kx8 static RAM seither an BK 2764 or t6K 27128 EPROM Input Output sconsole VO RS 232 serial port sline printer RS 232 serial port three Ebit progr grammabla TTL compatible parallel I O ports using a 8255 PPI salternate console RS 422 RS 485 To Order Call 1 800 635 3359 Tel 203 871 6170 Fax 203 872 2204 100 Ov 149 00 159 00 220 00 5189 00 Single Ory 189 00 199 00 294 00 259 00 BCC52 BASIC 52 Controller Board with 8K RAM BCC52C Lowerpower all CMOS version of the BCCS2 BCC521 Fullindustial temperature range BCC52CX CMOS Expanded BCC52 w 32K RAM MICROMINT INC 4 Park Street Vernon CT 06066 See us at the Embedded Systems Conference Booth 919 175 SOMA TIME fine However when coupling to an op amp LM3 18 and setting the gain to about 100 found that the
161. omponent width a smaller Figure 3b An MC68HC1 1 processor oversees the entire measurement process The processor s on board memory and peripherals keep extemal Support circuitry to an absolute minimum Melts the Price of 8051 ICE See us at We Embedded Systems Conlerence Booth 604 18 Issue 29 October November 1992 tid Reset Input 5 t_ Gad k tur 1N4001 Only 851 for iceMASTER PE The world s most innovative 8051 emulator is incredibly affordable Metolink s unique Advanced Emulation Technology AET potent pending delivers the best possible emulator volue or engineers consultants and students AET is o revolutionary design architecture that provides more eatures with 75 fewer components smaller board space and ower cost Emulator andor obe electronics are integrated in o n single package only 3 by 4 etotink also delivers leading edge customer service including 0 30 day money bock guarantee 10 day trial for qualified customers rentol plans and free technical support wW Upto 40 MHZ Oper otion ag Window ed User Interface wg 64K Emulation Code Memory a Serial link to Any PC te 64K Extemol Dota Memory wh Performonce Analyzer ag 28K Hardware Breakpoints wa Macro Cross Assembler wo 6K Trote Memory amp supports 8031 8032 s ngs Transparent Trace w Supports BXC751 8X 752 s View Trace While Executing a Reol Time amp Nonintusive wh Symbolic am
162. on of ADEL allows the creation of special test algorithms independent of those officially published ones embedded in the Prottusl04 system Issue 29 October November 1992 The Computer Applications J oumal INT ANIA ONA NEWS Edited by Harv Weiner Communication with any PC XT or AT is viaa parallel printer port which has been optimized for the fastest and most reliable performance The speed limita tions exhibited by PC bus based programmers are absent The parallel port is searched by the programmer and the connection made automatically All device library software is available through a Bulletin Board System or by floppy diskettes The Prot us104 is priced from 745 to 4995 B amp C Microsystems Inc 750 N Pastoria Ave Sunnyvale CA 94086 408 730 5511 Fax 408 730 5521 500 NAAA NEWS LOW COST NETWORKED MICROCONTROLLER The GCB11 an 8 bit networked microcontrol ler hardware and software package has been an nounced by Coactive Aesthetics Inc The 3 x 4 board based on the popular Motorola MC68 HC 11F 1 chip includes 32K of static RAM 32K of ROM and requires only a 5 volt supply The GCB1 1 includes 20 digital 1 0 lines and eight channels of 8 bit A D conversion Commu nication is provided by a standard RS 232 port and an RS 485 port for a multidrop network with up to 32 nodes Additional 485 drivers are on board for connecting a PC using the RS 232 to the RS 485 network without
163. on of Dunfield s Micro C compiler to recompile the code Pure Unobtainium has most of the odd parts you need to build the IR Link and MCIR Link projects includ ing the IR photodiode and LM3 11 for the IRSAMPLE C program Ed Nisley is a Registered Professional Engineer and a member of the Com puter Applications Journal s engineer ing staff He specializes in finding innovative solutions to demanding and unusual technical problems SOURCE Pure Unobtainium 89 Burbank Road Tolland CT 06084 2416 Fax Voice 203 870 9304 419 Very Useful 420 Moderately Useful 421 Not Useful The Circuit Cellar Project File Volume 1 ate m 2 5 The Circuit Cellar Proiect File Volume 1 has over 200 pages of new and expanded hands an projects and tutorials The Computer Applications Journal s editors have chosen a dozen rojeck from the Circuit Cellar Design Contest inde pendent submissions and topresponse articles to make a book with something for every interest1 now only 1 7 95 fincludes domestic delivery Order your copy today 17 95 Visa Mastercard Check
164. on the 87C054 are larger than the 80C5 1 192 bytes of RAM and 16K bytes of EPROM The OSD has additional RAM and EPROM areas that are not part of the normal 80C5 1 memory map One unique feature of the 87C054 is what Signetics describes as a soft Photo I The W Link can be used by your computer to overlay messages on any video signal The Computer Applications Joumal Matrix Figure Converting km RGB b NTSC involves modulating and adding difference signais ware ADC This ADC consists of an internal 4 bit DAC that feeds one input of a comparator The other comparator input can be connected to one of four I O pins The output of the comparator is tied to a status bit ina register that is testable by software A TV set often uses this logic for measur ing the AGC voltage during tuning A real time clock and other low preci sion analog measurements can also use it as a zero crossing detector The OSD of the87C054 consists of a128 character RAM array OSD RAM a 64 character font EPROM a video clock oscillator and the OSD logic The OSD logic accepts horizon tal sync HSYNC and vertical sync VSYNC signals and provides three digital video outputs for character information In the datasheet for this part these outputs are called VIDO VID1 and VID2 but they can also and perhaps better be thought of as RED GREEN and BLUE A multi plexer control output is also present to indicate when to display c
165. ons In your application you might be able to avoid the instrumented spark plug by drilling the head and directly mounting a pressure sensor no need to worry about water jackets Your data sampling and storage will be nontrivial 1 rotational resolution at 6000 RPM will need 36 000 samples sec On the other hand if what you actually need to do is detect detonation knock then there is a much simpler and cheaper approach All you need to do is to detect the audio frequency sound pinging produced by the detonation It s much more commonly heard in a car than on a bike but will be produced by any engine that is driven into detona tion The standard approach is to mount a vibration sensor on or near the head and use the filtered output to indicate detonation This is already being done in production of certain cars and trucks particularly with turbo charging The frequency of interest is somewhere around 6 kHz in the automotive application Your aluminum air cooled engine might be different You can find out by mounting up a sensor and smacking the head area with a hammer The predominant frequency produced by the sensor should be usable for detecting detonation Hammering on the engine is how the automotive sensors are tested Best source for a sensor might be the parts department at a GM dealer This technique is even used in laboratory dyno testing since the vibration sensor will detect detona tion well before even the be
166. or Money Order US Funds Only Add 2 00 lor delivery to Canada ar Mexico 4 00 far delivery to other non U S addresses The Circuir Cellar Project File Vol 1 4 Park Street Vernon CT 06066 Tel 203 875 2 199 e Fax 203 872 2204 X 10 Interfacing with PLIX The TW523 might be considered by some to be the perfect X 10 computer interface The complicated timing can be daunting to many though Throw a PLIX chip at the circuit and your troubles may be solved 74 Issue 29 October November 1992 FROM THE BENCH Jeff Bachiochi et me see the hands of all the engineers out there who still enjoy getting down on the floor and building forts and castles out of blocks or Legos with the kids For some of us doing such an activity with young children is a successful enough smoke screen to save us from the label eccentric Call me what you like but building a fantasy empire out of wood is just as rewarding as designing a product enjoy using the rules of gravity and balance with good old wooden blocks and building with Legos has its own reward even though working with them is a bit different Every task has its own set of rules An understanding of these rules and a bit of imagination is all you need to do well The same Photo 1 PLIX simplifies the task of X 10 interfacing by handling al the complicated liming The Computer Applications Joumal concept used in castle
167. ost Source Our line of disassemblers can help you re create the original assembly language source Thousands Of Satisfied Customers Worldwide PseudoCorp has been providing quality solutions for microprocessor problems since 1985 Processors RCA 1802 05 Intel 8051 Motorola 6801 Motorola 68HC11 Motorola 6809 MOS Tech 6502 Intel 8080 85 Zilog Z80 Mot 68k 8 10 Intel 8096 196kc Motorola 6805 WDC 65002 NSC 800 Intel 8048 Motorola 6800 Hitachi 6301 Rockwell 65C0 Hitachi HD64180 New For Information Or To Order Call Zilog Z8 Zilog Super 8 PseudoCorp All products 716 Thimble Shoals Blvd Suite E require an IBM Pc Newport News VA 23606 ee 804 873 1947 FAX 804 873 2154 170 Oe TIME use repetitive sampling although now must use ECL all the way till the DSP accesses the data I hoped to leave the high frequencies on the other side of the ADC Well if anyone knows who can contact about high speed RAM drop me a line any help received is always greatly appreci ated including that already received Msg 58491 From J OE PIERSON To TERRY NORRIS l too am working on a high speed data acquisition system I am using the Analog Devices AD 9038 300 MHZ ADC and have the following comments suggestions conceming your problems 1 Fast ECL CMOS BiCMOS memories can be obtained from Cypress Semiconductor IDT Mosel and Motorola 2 You can latch the data coming out of the ADC with a ECL latch and
168. ournal CIRCUIT CELLAR LIP YK THE COMPUTER APPLICATIONS JOURNAL FOUNDER EDITORIAL DIRECTOR Steve Ciarcia MANAGING EDITOR Ken Davidson ASSOCIATE EDITOR Lisa Nadile ENGINEERING STAFF Jeff Bachiochi amp Ed Nisley WEST COAST EDITOR Tom Cantrell CONTRIBUTING EDITOR John Dybowski NEW PRODUCTS EDITOR Hatv Weiner ART DIRECTOR lisa Ferry STAFF RESEARCHERS Northeast John Dybomki Midwest Jon Elson amp Tim McDonough West Coast Frank Kuechmann Cover illustration by Robert Tinney PUBLISHER Daniel Rodrigues PUBLISHER S ASSISTANT Susan McGill CIRCULATION COORDINATOR Rose Mansella CIRCULATION ASSISTANT Barbara Maleski CIRCULATION CONSULTANT Gregory Spitzfaden BUSINESS MANAGER Jeannette Walters ADVERTISING COORDINATOR Dan Gorsky CIRCUIT CELLAR INK ISSN 0896 8985 k published bimonthly by Circuit Cellar Incorporated 4 Park Sweet Suite 20 Vernon CT 06066 203 875 2751 Second class postage paid at Vernon CT and additonal offices One year 6 issues subscripton ram USA a d sidie CanadaMexico 21 95 all other counties 32 95 All subscription orders payable in U S funds only Wainternatonal postal money order or check drawn on U S bank Direct subscription orders to Circuit Collar INK Subscriptions P O Box 3050 C South eastern PA 19396 or call 215 630 1914 POSTMASTER Please send address changes b Circuit Cellar INK Circulation Dept P O Box 3050 C Southeastern P
169. oving and restoring the original interrupt vectors If you don t com plete these steps then a random serial interrupt after your program finishes will use the wrong vectors and cause a system crash RING BUFFERS Each serial port opened by SERCOM is assigned its own set of receive and transmit buffers see Figure 1 Looking Listing 2 Hooking he serial interrupts into he system and setting up he 8250 must be done properly to avoid a system crash Set the interrupt vector for COM1 _disable0 Read old interrupt and set new one coml c c gt old _dos_getvect c gt int_number _dos_setvect c gt int_number int_serl break Enable IRQ4 COM1 IRQ3 COM2 on 8259 interrupt val inp INTC_MASK val amp c gt irg_mask outp INTC_MASK val 8250 hardware setup val inp SREG LSR val inp SREG RBR val inp SREG LCR val amp Ox7F outp SREG LCR val outp SREG IER 1 outp SREG MCR OxB All done _enabl e0 The Computer Applications Journal controller Read and discard status Read and discard data Rst DLAB for IER access 01111111B Enable Data Ready INT Enable OUT2 RTS and DTR restore interrupts to processor Butter Empty After Interrupt HEAD TAIL TAIL HEAD t 1 i 1 Read One Character Wraparound E I a e a Figure 1 A ring buffer uses a pair Of pointers to keep back of the be
170. p Source Level Debug wo Built in Self Te t a Cl today for FREE DEMO DISK 800 METAICE 800 638 2423 Zar Metalink Corporation PO Box 1329 Chandler Az 85244 1 329 ie Phone 602 9260797 FAX 602 926 1198 es The Computer Applications Joumal 111 emission acceptance angle a larger 50 mm x 50 mm sensing area and an MC68HC11 microcontroller unit MCU The entire measurement process refer to Figure 2 is requested by an external robot controller to the smart sensor Once initiated the MCU controls and reads the sensor through a three line interface CLR CLK and DATA The MCU then calculates the center of the object inserted into the square based on absence of light at individual receiver elements in two dimensions The object position is coded using 6 bits for each dimension Oncea GO request is received the computer sequence is as follows refer to Figure 3 for the schematic The MCU resets U21 U22 turning on the pair D7 and Q7 and latching their condition into the synchronous serial peripheral interface SPI port It then sequences down the line along the horizontal x axis to D32 and Q32 storing each pair s condition in on board RAM in single byte groups The scan continues in the y direction without interruption to D72 and Q72 Notice the reverse sequencing process 7 6 5 4 3 2 1 0 15 14 39 38 37 36 35 34 33 32 47 46 73 72 This feature allo
171. pa is declared i n t so it may return a value about the success of the function call did not show you the coding that checks if the arguments passed to setpal are within range and if the current screen mode is 16 color VGA The first operation set pa 1 performs is determining the comple ment of hue referred to as euh in the coding Knowing euh is essential for establishing the saturation Refer to Figure 3 which shows a horizontal slice through Figure 1 at the equator This figure shows a vector that indicates a fully saturated hue drawn in this case at the orange azimuth Adding a vector 180 away from the hue vector reduces the radial magnitude of the hue because the saturation is the magnitude of the Listing When de amp mining the proper red green and blue components a normalization process must be done to ensure he final values are between 0 andi float mag_blue float x float result result maxl x2 x maxl x x4 delx return result minl x xl mini x5 x float mag_green float x float result result x minl xl x maxl x x4 return result 0 minl x3 x 0 delx float mag_red float x float result The Computer Applications Journal continued radial coordinate euh is just such a vector It is determined simply by Listing continued adding 1 2 to the hue if the hue is less result maxl x x2 0 minl x3 x 0
172. plitudes exceeding 10 V Resistor pairs R11 R12 and R13 R14 serve as voltage dividers for the VSYNC and CSYNC outputs respectively An LM 339 comparator U5 serves as an inverter for the sync signals because the modulator circuits require active low sync signals There is a great tendency with video circuits to make the coupling capacitors very large to pass the low frequency sync components 60 50 Hz typically into low impedance nodes The TDA4820T has a moderately high input impedance on pin 2 Because the black level is stored in C14 the value of Cl4 should be kept close to 0 22 uF The Computer Applications J ournal THE 87C054 MCU WITH OSD The 87C054 microcontroller U3 accepts composite sync and vertical sync signals from the sync separator and provides RGB digital outputs for character data The multiplexer con trol output VCTRL connects to the video switch U2 a JRC2244 Inductor L1 and capacitors C8 and C9 form a video dock oscillator that determines the width of a character font dot The values of these compo nents are not critical but are typically chosen such that a video dot width is equal to the spacing between scan lines This oscillator is killed at the leading edge of the HSYNC signal and allowed to startup at the trailing edge Such synchronization causes the oscillator to start at exactly the same point from one scan line to the next causing character dots to appear in exactly the same spot on eac
173. pment of 8051 family programs by allowing execution and debug without a target system The 8051 SIMulator is a screen oriented menu command driven program Pog da aus fill d Paramotor Lee OT ng doubling as a great learning tool 99 Single Board Address to output delay CE to output delay CEto outpt delay Output disable to output float Address to output hold Computers 8031SBC A fast and inexpensive way to implement an embedded controller 8031 32 processor 8 parallel 1 0 up to ADDRESSES 2 RS 232 serial ports 5 volt operation The development board option allows simple debugging of 8031151 family programs 9Qea 80C552SBC 10 bit 8 ch A D 2 PWM 1 RS232 amp 2 RS232 422 485 serial ports sockets for 64k ROM 64k RAM 5 volt operation optional RT Clock w battery COG vaio PD 2k EEPROM Development board version available Call for pricing Call for your custom product needs 16 Free Quote Quick Response Min Max Mn Max VISA MasterCard AMERICAN Clock fall to MREQ fall delay 25 25 asterCar PEMA Data read setup time 15 a 10 A HiTech Equipment Cor 200 Actviy Road k n Diego CA 9 S12 PAX 619 530 tae Figure 4 Using the timing diagrams along with typical discrete gate delays not shown the minimum aocess lime necessary for memory components can be calculated 619 566 1892 i6C The Computer Applications Journal Issue 29 October November 1992 85 cycle is
174. pular BXC518051 8052 BASIC compiler 800 Call Now 508 369 9556 or FAX 508 369 9549 Binary Technology Optional aluminum case 45 monitor debugger source 25 battery backed real time clock 39 All components are manufactured to exacting standards and warranteed for one year P O Box 541 Caride MA 01741 ae 103 Fano dss SONILIIS INIG E E gt PRODUCT DEVELOPMENT MADE EASY With EMAC s feature packed Single Board Computers and easy to ge BASIC compiler your producVapplication can become a reality in no time EMAC s BASIC compiler allows you to develop the software right on the Single Board Computer No more time lostlinking download ing or burning EPROMs immediately see the results of a program change Make modifications or dump memory right on the board Since this BASIC is compiled and written entirely in assembly language your programs will fly_Full networking ail at your fingertips But you say you need multitasking how about up to 32 tasks with priority scheduling built in No adding libraries And this multitasker is as easy to use as the BASIC language f BASIC is not your language of choice EMAC offers Assembler ANSI C and Forth you choose But enough about the software software is nothing without a good hardware foundation with the features you need to make the job easy Need to drive relays Take advantage of 8 high drive d lig yt lines Have some digital input lines tha
175. pulses was to load Timer 0 with a value and wait for it to time out because the 803 1 has no dedicated pulse generation hardware Thus the first data reduc tion step was to convert the captured times from absolute to relative by subtracting each entry from the previous one working backwards through the array naturally TheISiU6o timing is alittle more complex than you might expect because the turn on and turn off delays for each pulse are not equal In other words although the sum of the ON and OFF times is correct the pulse appears to be ON longer than it really is My experiments showed that the correction is about 220 ps for strong signals The code subtracts that amount from the ON time and adds it to the OFF time as part of the abso lute to relative time conversion As mentioned an adjustment is also needed to account for the loop time overheads However managed to match the capture and reproduction loop time overheads so there was no need for an explicit fudge factor In effect the code loses just as much time acquiring the signals as it does playing then back Think about it The next step is to divide all these times by eight which ensures that the 68 Issue 29 October November 1992 Listing 1 This pair of loops waits for the first IR signal then begins capturing 3 byte time stamps for each edge e Waitfor an IR signal or cancel keystroke SETB IRECEIVE CLR FOFLAG ensure input mode indi
176. r SAS aha OL eae PAL GAL EPROM Hee EEPROM if i FLASH MICRO ere 475 00 ns S a7G751 4 MEG EPROM 8 amp 16 bit oVe 87c752 22V10 amp 26CV12 GALs 26CV12 PIC Parts added at your request 27C040 Free software updates on BBS 93046 Powerful menu driven software XC1 736 400 MHz LOGIC ANALYZER up to 128 channels up to 400 MHz 16K samples channel Variable threshold levels 8 Extemal clocks 16 level triggering 799 LA12100 100 MHz 24 Ch 1299 LA32200 200 MHz 32 Ch 1899 LA32400 400 MHz 32 Ch Price is Complete Pods and Software included Call 201 808 8990 y Link Computer Graphics Inc 369 Passaic Ave Suite 100 Fairfield NJ 07004 fax 808 8781 1C Multiplexer M odule Banner but it has fairly poor resolution 5 12 mm Other light curtain devices offered by Banner and Sick Optoelectronics simply provide presence detection or the edge measurement of a surface A 1 D C shape sensor is available from Frost Controls that measures an object s size using an analog signal proportional to the area blocked and it also can be constructed to detect position However this unit is 12 5 mm thick which is the minimum displacement between measured dimensions Due primarily to cost and complexity did not consider the various types of laser based position measurement systems Keyence 14 400 for this application 4 Evidently no commercially available position measu
177. r d s 72 hr m l e Prototype to Production FR 4 Plated Thru Teflon Polyimide UL Recognized I M P A C Call us for an instant quote 24 hrmodem for easy transfer of Drill amp CAD files Free Tooling On First Order up to 200 Superior Quality at Competitive Prices Multifunction Board adds LCD Keypad UART A D and 24 I O lines CAPITAL ELECTRO CIRCUITS BASIC 52 or Monitor Debugger in EPROM C Compiler 100 lota Systems Inc POB 8987 Incline Village NV 89452 PH 702 831 6302 FAX 702 831 4629 144 142 The Computer Applications Journal 7845 Airpark Road Gaithersburg MD 20879 301 977 0303 Fax 301 990 6715 Issue 29 October November 1992 63 DEPARTMENTS Firmware Furnace From the Bench Silicon Update Practical Algorithms ConnecTime 64 issue 29 October November 1992 Since the introduction of the HCS Il home control system one of the most requested new features has been the ability to send IR codes to consumer electronic equipment The new MCIR Link makes those requests reality The Computer Applications J ournal FIRMWARE FURNACE Ed Nisley Extending Your Control The HCS II MCIR LINK f you wish hard enough it will come true is an aphorism often attrib uted to the Walt Disney School of Engineering But at least in the wonderful malleable world of firm ware wishes sometimes do come true Back i
178. ransistors rise and fall time Although SPI rates as high as 2 1 megabits per second are possible Siemens specifies the receiver with a 6 ps maximum rise and fall time Still yet testing yielded 129 us due to the effect of coupling with the multi plexer resulting in an optimum period of 135 us 7 41 kHz which isn t one of the four selections in master mode SPI polarity and phase were initialized for stepping on the falling edge of the clock and data latching on the rising edge Calculating position requires determining the nature of the data from the arrays D ata is classified as reliable or unreliable Unreliable data refers to noise any pattern other than one consecutive group of blocked elements or signal absence all elements unblocked or all elements blocked with appropriate codes transmitted for each type of condition Reliable data is processed by a simple algorithm to locate the object center As I noted earlier the microcon troller uses six parallel bits per dimension to code the calculated object position within the array of the sensor In addition raw position position codes and error codes are sent to the optional terminal for user verification if desired The 26 pin dual row header on the circuit board provides RS 232 interfacing when a 25 to 9 pin adapter is used Nine of the 25 pins are used to avoid circuit conten tion with the parallel output on the same header Eventually will want robus
179. rates as HUE goes from blue to orange This feature emphasizes the change in intensity When you apply HLS to the problem a tapestry of science and art allows a magnificent visualization of the event Other analytic functions produce different effects Part of the fun with the HLS modal is just experimenting with different functions Creative functions lead eventually to a library of function definitions that might aptly be called color effects With a little practice you will find that going fames R Furlong is a research scien tist with a defense related organiza tion in Arlington VA He develops constitutive models for materials undergoing shock used in large scale hydrodynamic computer codes He is also head of software development for Eclectic Systems in Springfield VA REFERENCES 1 Tektronix 4107 4109 Programmer s Manual Appendix E 1982 2 IBM Personal System 2 Display Adapter Technical Reference International Business Ma chines Corporation 1987 3 ZeuS Technical Description and User s Manual Computa tional Mechanics Consultants Inc Baltimore MD 1990 4 F Whipple Meteoric Phenom ena and Meteorite The Physics and Medicine of the Upper Atmosphere University of SOURCE Readers interested in experiment ing with the HLS model may contact Eclectic Systems for a free copy of the utility MYPAL MYPAL is an interactive program used to define palettes in HLS space HLS coordinates
180. re hydrant of data pointed at me I m not yet worried some combination of digital and analog techniques can minimize that In any case these bikes are running on an inertial dyno that a friend and constructed it s just like D ynojet s and there s a PC already in the vicinity ready to swallow more data PII keep on plugging looking for an elegant and or cheap especially solution to this problem The Computer Applications Journal Issue 29 October November 1992 95 SOAS TIME what s the best way to sample a 50 MHz signal without paying an arm and a leg In the next discussion we look at several different techniques and their tradeoffs Msg 58226 From TERRY NORRIS To ALL USERS am in need of help My problem is want to do some analog to digital conversion at very high speeds The data will eventually be sent to a PC Problem is the signal being sampled can range up to around 50 MHz and that means much higher sampling rates A PC would rather format a hard drive than be forced to process data at that rate The fastest ADC can find supports a 100 MHz sampling rate not good enough for a clear display without averaging believe if the signal were shifted into a high speed analog shift register could slowly shift the signal out at a sample rate could use Know there are analog shift registers out there for reverbs and the like but are there high speed shift registers Any help would save some headaches Ms
181. read from PLIX REM RrWw CP 1128 Combination Programmer 1295 00 v Supports AMD s v Supports upto 28 pinE MACH110 210 120 130 EPROMs and bipolar 230 EPLDs Altera s 900 1800 series and MAX EPLDs Cypress CY7C361 Lattice s irp LSIT032 amp pLSI1032 National Semiconductor s 5D amp 7D devices and MAPL devices V Qualified ond recommended by AMD Lattice National Semi conductor Signeticsand others v Utilizes only manufacturer ap proved programming algo rithms PROMs including the microwire C devices Supports Dallas Semi conductor NVRAMs and TI psP320 Micro chip PIC microcontrollers V Lifetime FREE software updates available via BBS and US Mail V Call for a DEMO disk and literature pack Made in the USA EPROM PROGRAMMER EP 1 140 E EPROM amp controller Programmer 695 00 WY The EP I 140 supports NEC s 27C8001 8 Mbit EPROM all27C240 4 Mbit 16 bit EPROMs FLASH EPROMs NVRAMs and all microwire EPROMs Y All Intel AMD and Signetics 40 pin controllers supported directly Y Qualified and recom mended by Intel Signetics National Semiconductor and others Lifetime FREE software up dotes available via BBS and US Mail W Risk free thirtydoy money back guarantee VW Made in the USA With lifetime FREE software updates you can t go wrong and BP Microsystems offers a thirtyday money back guarantee to ensure product satis faction Remember BP Microsystems
182. relays 10VA 49 9 RH 8 RELAY CARD 10 amp SPDT 277 VAC 68 EX 16 RELAY EXPANSION CARD 16 channel 59 91 ANALOG TO DIGITAL 8 10 amp 12 BIT RESOLUTION CONNECTS To RS 232 y4 CONNECTS to RS 232 ADC 16 A DCONVERTER 16 channel 6 bit 99 95 Input temperature voltage amperage pressure ener usage energy demand ight levels joystick movement ant a wide variety of other types of analog signals Inputs may be expanded to 32 analog or 126 status Inputs using the AD 16 or ST 32 expansion cards 112 relays may be controlled using EX 16 expansion cards Analog inputs may be configured for temperature input using the TE 6 temperature input conversion RS 422 available PS 4 port selector may be used to canmect satellite ADC 16 nterfaces up to 4 096 analog inputs 16 384 status inputs and 14 336 relays Call for info on 10 8 12 bit converters terminal block and cable sold separately ST 32 STATUS EXPANSION CARD a 79 95 put on off status of relays switches quipment hermostats security devices smoke detectors and other devices including keypads and binary coded outputs gt rovides 32 status inputs opto isolators sold separately TE 8 TEMPERATURE INPUT CONVERSION 49 95 neludes 8 temperature sensors amp terminal block femperature ranges minus 40 to 145 degrees F 9S 4 PORT SELECTOR 4 channels RS 422 79 95 alphabet aes aon into 4 bet ae ports other serial _interfacin yoducts availab Eg
183. rement PAL U9 The clock to the PAL is enabled and disabled to save power when actual measurements are not in progress The three data inputs for the PAL the LCD display and dual DAC data inputs populate the microprocessor s port 0 The DAC is the only device actually addressed as a memory device i e using the MOVX instruction A single 9 volt battery powers the TDR Automatic power down is accomplished with the aid of PMOS FET Q3 and NPN transistor Q 12 When the operator presses the on switch S1 the gate of Q3 is pulled low applying power to the LM 3 17 and subsequently tHe micro controller At power up all processor port pins go high including P1 7 which keeps Q3 and Q 12 turned on To power down the processor simply drops Pl 7 The sum of the leakages of Q3 and Q 12 which are extremely low and comparable to the self discharge rate of the 9 volt battery equals the amount of standby current when the system is off usc us g LAHCTOO zecuioz CLK 2 CLK SLEEP Testo VSD z on ERA BASIC Developers Tool ATTENTION BASIC 52 BASIC 180 and BASIC I DEVELOPERS Finally an advanced development environment for BASIC single board computers BDT combines ail the tools you need including Editor Compiler Debugger and Terminal emulator In a powerful fast easy to use ond totally Integrated package Lio 138 Cali insert ladent DRAWLINE BOT Ut wat WAV ar G deg Line use the Bresende a igor ithe Tirst
184. rement device fit the needs of this application so developed a sensor and coupled it to an MC68HC11 microcontroller 5 6 7 The pairing of the measuring element and the inexpensive microcontroller yielded an externally controlled programmable sensor that reported hole in the middle parallel serial interface DESIGN CRITERIA measurement results through a The primary design goal for my sensor was that it detect the direction Photo l The sensor uses pairs of LEDs end phototransistors b sense the position of a plant cutting inserted in the and magnitude of bend on a geranium cutting stem s base relative to the robot s grasp To make this determina tion the robot is directed to position geranium cuttings in a fixed location in the workcell then to measure FREE CALL HELP 09 The Computer Applications Joumal b00 93 00hd PARADIGM LOCATE PARADIGM TDREM PARADIGM DEBUG Comprehensive software development tools for all Intel 80C186 and NEC V Series microprocessors e Borland C and Microsoft C C support e Choice of stand alone or in circ uit emulator debugging e Unlimited toll free technical support e 30day money back guarantee Help IS Available can today for complete product information and embedded system application solutions You won t be disappointed PARADIGM Proven Solutions for Embedded C C Developers Paradigm Systems 3301 County Club Road Suite 2214 Endwell
185. ring DOS and programs Perfect for booting diskless workstations Hard Disk Drive replacements available PRODUCTIVITY VISA ENHANCEMENT AMEX PRODUCTS MCHG 26072 Merit Circle Ste 110 Laguna Hills CA 92653 1 800 451 DISK 714 348 1011 FAX 714 348 1310 82 Issue 29 October November 1992 The Computer Applications Journal Low Cost Reliable High Quality ROM Emulation from the Creators of PROMICE Emulation of up to 1 Mbit ROMs 4 Mbit soon Supports any ROM type DIP or PLCC Supports high speed ROMs Supports any word size up to 2048 bits wide Host software for DOS Unix Mac VMS Battery backed memory Intelligent micro controller based unit SMT CMOS layout for robustness Tiny size 2 5 x 3 8 x 0 9 Unbelievably low price ROMboy from the authority in firmware development tools Grammar Engine Inc Orders 614 899 7878 West 415 750 0219 FAX 614 899 7888 See us al the Embedded Systems Conference Booth 705 155 Oops oh yeah it s in register 1FH uss 4 extar F TXAQO AZ ocoos 48 ctsex RXAG 613 26 4S SQ rxat RTSON TXAL TEER RxsvcTBin A CKS Y19 2725662256 UPP AL4 A13 A12 DDDDD Neoee on DDDDD NOrNnH DD oF EPROM RAM Ss The bits I was setting in register 3FH happened to have the interesting property of relocating the 180 on chip I O addresses Thus after the OUT ins
186. rive this board manually with a terminal emulator a simple PC program or your own home control system That s about as complex as the user interface gets so won t say much more about it Instead I Il explore the MCIR Link firmware and des cribe some of the gotchas that make IR control such a challenge Along the way you ll dis cover techniques for your own projects and perhaps find new respect for your TV set s lowly remote control receiver REMOTES UNCONTROLLED The first step in any project should be figuring out what you need to do What you need to do here is add to your home control system the capability to recognize the JR signals of the devices you wish to incorporate which you do by training the MCIR Link with the remotes To begin a quick review of the basics of IR Lead in Burst frequency The first chunk may have a long lead in burst to wake up the receiver In some cases this burst pulls the link out of a power down deep sleep mode but usually itis just a way to distinguish an incoming signal from the background clutter Each manufacturer uses a different scheme to stuff bits into the IR signal In fact two remotes from the same manufacturer may use different encodings although this inconsistency is less of a problem now that complex A V systems are the norm rather than the exception In principle this variability reduces the chance that an IR signal will trigger the wrong remote
187. ros To prepare a string for transmis sion all that is necessary is to stuff the message in the buffer with the check sum digits set to ASCII zeros and call theV ER FY routine To check a mes sage for correct checksum simply call the V ER I FY routine and check the CHKERR flag on return Once the checksum verification if required has been performed you still need to process the packet to see if it belongs to this terminal and if it does then you need to determine what action the network controller is asking you to take The PROCESS routine first scans the packet converting characters into upper case until the end of the packet has been reached Next the first character is examined to determine if the packet has checksums or not and a pointer is set to the NODE1 D position of the packet The NODE D in the packet is compared with the N 0 D E I D variable If there is no match the packet is ignored and you wait for the next network message If it does belong do this terminal you can process the body of the network message NETWORK COMMANDS AND SYNTAX The real essence of a network message is to carry a command from the network controller to the terminal or carry a response from the terminal back to the network controller Table 1 shows the syntax of the commands available for operating the TV Link terminal These commands allow the HCS II Supervisory Controller to manipulate ports on the 87C054 format text for
188. s I d rather just crank the clock So grabbed a 180 board and headed for Zilog Mission Possible hope double the performance or bust NO FREE LUNCH In my view the performance of general purpose computers boils down to bus bandwidth Yes architecture compilers and system design have an impact but in today s competitive environment religious wars to the contrary gaining a significant advantage in these areas is difficult However the performance gains of a faster clock come at a price the need for a corresponding faster memory Without it any improvement will be lost to the dreaded wait state In fact boosting the CPU speed without facing up to memory bottle necks can lead to a somewhat patho logical decrease in performance The reduction happens when the granular ity of a wait state exceeds the percentage speed up in the clock This scenario is most easily illustrated with RISCs that call for 1 clock bus cycles In this case the granularity of adding the first wait state is 100 i e a 1 to a 2 clock bus cycle Now what happens if the clock is boosted without faster memory CPU Core vo Power Down Modes SLEEP VO STOP SYSTEM STOP stop Running stop stop stop stop stop stop stop IDLEt STANDBYt On Chip Running Recovery Source osc CLKOUT Running Running Running Running stop Running Running Running stop stop Notes t IDLE and STANDBY modes are o
189. s beyond the predictable to the unpre dictable environment No formal methodology exists for designing automation systems that work with biological products that are of variable gripper __ Sash cutting device t tray supports trays not shown Figure The robot s job is to pick plant cuffings off a conveyor belt trim leaves and the stem and insert the cutting into a plug of peat The sensor helps tie robot compensate for the natural bend in the plant s stem size shape color orientation and stress or strain relationships 2 This scenario presents quite an inviting challenge and who can resist one of those Not many Fundamental research is widely underway to establish methods for the design of cognitive machines robots that can autonomously or semiautonomously operate with contingencies THE ROBOT Most robots are capable of repeat ing a preprogrammed sequence of operations however for robots to operate effectively in a changing or uncertain environment the machine must be equipped with sensors Therefore a key activity in robotics research is examining methods for coordinating information from various sensors to control robotic actions 3 At the Georgia Station Mecha tronics Laboratory research is investi gating pragmatic techniques that allow robotic systems to accommodate the significant variability present when handling and processing living plant materials This accommodation o
190. s with shuttle control knobs but it works like a champ for remotes with vast rectilinear arrays of tiny keys If you intend to store a zillion keys write a program on your PC to keep track of em please PLAYING DATA By comparison playing back the stored data is straightforward The data records are stored nose to tail in RAM preceded by a two byte record count and followed by another pair of zeros so the firmware simply scans through the records to find a matching record number Although could have included an overall record size in each record found that scanning through each record and decompressing all the data requires only about 150 ys per pulse Again your mileage will vary but scanning to the last of 100 records each with 30 pulses might take 400 ms While this may sound excessive 70 Issue 29 October November 1992 Vee R4 2709 D2 Rsd LED Figure 4 The IRSAMPLE C program uses this circuitry to capture raw IR signals from a remote control without the processing imposed by he normal I 1U60 receiver Adjust Also the LED is offunder ambient light and w for an IR signal remember that typical IR signals weigh in around 100400 ms them selves The data expands back into the 3000 byte buffer used to capture it in the first place with each value occupying the low two bytes of each three byte entry The values are then multiplied by eight to recover clock cydes which puts the timer overflo
191. s of euh are modifiedby 1 sat sat0 to establish the correct radial magnitude of the RGB components of hue If 1 sat satO is 1 hue and euk will cancel each other the hue radius will be 0 and the resulting color will bea gray tone Finally each component is multiplied by an intensity value mapping the RGB values into video hardware space The VGA is an 18 bit color device It uses 6 bit values for RED GREEN and BLUE Hence the range for any component is 0 63 The float variable TENOis used to hold the value 63 The net intensity is simply Listing 3 The function se t_ regis used to define a color fora VGA register VAAA Y TEN 0 times the lightness or in Mda vivn nsu setpal the variable li te TOTAL Defining the color foraVGA PACKAGE register is most easily done by making the video interrupt BIOS INT 10 call PERFORMANCE 2 Listing 3 shows the C code for the QUALITY PRODUCTS subroutine s et_r eg which uses the RESPONSIVE SERVICE Microsoft C in t86 function to make RELIABLE DELIVERY such a call All values used by the SOLID STATE DISK 124 BIOS calls must be integers so each Y Card 2 Disk Emulator EPROM Flash and or SRAM color is cast with the i n t type when 1 Meg Total Bootable se t_r eg is called and then recast as unsigned chars before being loaded into the r eg s union structure Inside set_reg two BIOS calls eae B are made The first call sets the palette S E register with an attribute
192. s traffic while performing its routine functions then keeping it on line without the use of a hardware UART makes no sense When considering functions such as serial communications the choice of using a hardware or firmware approach is usually clear cut based on the prevailing needs Some decisions may not be quite as apparent and taking the wrong approach can cause significant problems down the road Although much can be done using a firmware only approach there comes a point of diminishing return where a little hardware can save you much heartache One function that I ve never felt compdled to use a purely hardware approach on is keyboard scanning Although special cases exist where a strictly hardware approach makes a great deal of sense I ve had good results using firmware based scanning particularly because the process load is extremely minuscule Before show you several different arrangements for scanning a keyboard lIl familiarize you with the common requirenents of a keyboard driver THE FUNCTIONS OF A KEYBOARD DRIVER The basic functions of a keyboard driver consist of doing a contact scan checking the state of all the key contacts debouncing a key closure implementing the keyboard style and performing the key code translation Contact Scanning Y Set KEY NUMBER KEY_COUNTER Increment Set LAST KEY Set nokey gt DEBOUNCED 0 Sel LAST KEY KEY_NUMBER Key Processing Y DEBOUNCED
193. schematic Single Socket Programmer also available 550 00 Split and Shuffle 16 amp 32 bit 100 User Definable Macros 10 User Definable Configurations e intelligent Identifier Binary Intel Hex and Motorola S 2716 to4 Megabi 1 39 ew intelligent Averaging Algorithm Programs 64A in 10 sec 256 in 1 min 1Meg 27010 011 n2 min 45 sec 2 Meg 27C2001 in 5 mm Internal card with external 40 pinZIF Stand Alone Gang Programmer 8 ZIF Sockets for Fast Gang Programming and Easy Splitting 20 Key Keypad Internal Programmer for PC Reads Verifies and programs 2716 32 32A 2 ft Cable 40 pin ZIF 64 64A 128 128A 256 512 513 010 011 301 2702001 MCM 68764 2532 4 Megabits Automatically sets programming voltage e Load and save buffer to disk e Binary Intel Hex and Motorola S formats e No personality modules required 1Year warranty e10 days money back guarantee Adapters available for 8748 49 51 751 52 55 TMS 7742 27210 57C1024 and memory cards Made nUS A EMPDEMO EXE available BBS 916 972 8042 NEEDHAM S ELECTRONICS 4539 Orange Grove Ave Sacramento CA 95841 Monday Friday 8 am 5 pm PST C 0 D Co Call for more information 916 924 8037 FAX 916 972 9960 1 101 The Computer Applications Journal Issue 29 October November 1992 SOO TIME positive and the negative supplies have to be reasonably
194. sed Com puter Control by Ken Davidson Circuit Cellar INK 3 May June 1988 One other void had to be filled before X 10 became more practical In addition to sending commands the capability to listen for then was important as well X 10 s TW523 corrected this omission This module error checks any data received and sends it to the computer again during zero crossings Like transmissions the user is responsible for decoding the received binary data See The X 10 TW523 Two Way Power Line Inter face by Ken Davidson Circuit Cellar INK 5 Seotember October 1988 PRE PLIX GYMNASTICS Confusion as to what makes up an X 10 transmission still exists even with these two interfaces The X 10 format consists of a serial data stream The Computer Applications Joumal containing a start code a housecode and a function code Table 1 shows valid housecodes and function codes Each bit of data in the bit stream consists of six 1 s time periods Each time period is 2 778 ps apart or six per 60 Hz line cycle Figure la If the first period is synchronized to the zero crossing of the 60 Hz line then the remaining five time periods will be in step with each zero crossing of a three phase power line and in principle be detected on systems with three phase power A data bit with a value of 1 is sent as On On On Off Off Off Figure 1 b whereas a bit value of 0 is sent as Off Off Off On On On Figure Ic
195. some of Sony s ADCs They make some very fast 8 bit ADCs 300 will get you a 500 MHz ADC 5 You mentioned that you want to measure 50 MHz signals are these periodic or one time events If they are periodic then don t bother using the high speed ADCs they won t buy you anything HP uses 20 MHz ADCs in their 20 GHz scopes Just remember to put a sample and hold in front of the ADC since most of the ADCs in the 20 MHz range have lousy full power bandwidth Msg 58549 From TERRY NORRIS To J OE PIERSON You have closed the link on a difficult path for me Are you looking for a 68xxx or 386 486 ANSI C cross compiler for DOS OR UNIX Is com plete source code to your compiler important to you How about a complete Standard C library implementation including floating point emula tion Hundred Acre Consulting is now offering GNU C sup port packages in several cross compiler configurations Each Package includes the GNU ANSI C compiler from the Free Software Foundation a complete Standard C li brary with hooks for your own file system implementa tion several support utilities and one year of support at no additional charge Platforms supported include MS DOS Sun 3 and Sun 4 with SunOS 4 1 and Interac tive or SCO UNIX Call today for more information GNU Support Package 495 Hundred Acre Consulting 1260 Terminal Way Suite 26 Reno NV 89502 Phone 1 702 329 9333 Fax 1 702 329 9566 info pooh com 17
196. ssary to load IBM VGA hardware with RGB values so you can think in terms of HLS but speak to your computer in RGB also introduce an extension to the I ILS mode that allows more color possibili If you thought RGB red green blue was the only or best way to represent color think again The Hue Lightness Saturation HLS model can actually be better than RGB at representing colors in some applications 50 Issue 29 October November 1992 The Computer Applications Joumal ties and unlocks the 262 144 colors of which the VGA is capable MODEL COORDINATES Figure 1 illustrates the conceptual framework for the HLS model 1 The figure is three dimensional because the model has three coordinates They are defined as follows Hue Hue is what many of us would commonly refer to as color Red green and purple all are hues but in the context of the HLS systen they are colors absent of a definition for lightness dark red or bright red and saturation pure red or pink Hue is perceived as the azimuth coordinate on the mode This designa tion isn t arbitrary but rather it is a consequence of a special additive nature of the RGB system itself In Figure 1 notice that if blue is arbi trarily taken as the starting point you can smoothly scroll through the cyans greens yellows reds magentas and finally wind up back at the beginning namely blue without any loss of continuity You will have the sense t
197. st operator can hear it Msg 58492 From KELLY DRESSER To MIKE RAPP Thank you Mike for your reply You confirm my general hunches about how I m going to get the info want I m still hoping for some unorthodox manner in which to skin this cat Already with a water cooled two stroke I ve had much better than beginner s luck at sensing the cylinder pressure by epoxying the sounding disc from a piezo squeaker on a flat spot next to the spark plug Got an incredibly clean and strong signal The piezo even survived the temperature but did display a whopping DC signal that varied with the rise and fall of the head temperature However an air cooled four stroke is a lot hotter a lot noisier mechanically and there s no place to stick the thingumy Mr Kistler makes good stuff but it s out of reach in cost M aybe someone has found another rugged sensor that will work in this application Your suggestion about using a resonating piezo sensor from an automobile engine is a technique want to try last since I really do want a pres sure trace for some combustion phasing fiddles plus be able to detect knock and doing both with the same sensor still attracts me I ve been though all the recent SAE papers but without anything looking really good except maybe an under the spark plug washer piezo again that Nissan I think has used in the past Any experience by anyone out there with such a sensor As far as having a fi
198. string String for OSD display can include escape sequences for text formating color selection etc Wxnn Write to register x for use within a string functionally equiv to the Rx nn command Special characterss for use within a string of text E End of Display at current position B Background Space S Split Background Space N NEWLINE Table 1 The set of supported commands resembles that of most of the other HCS Il network modules 87C054 and the part does not have a transmitter pin or receiver pin In this application the serial data transmission and reception has been performed in software The routine that handles serial transmission and 48 Issue 29 October November 1992 reception was taken from the Signetics BBS 800 45 1 6644 It was originally designed for the 87C75 1 and had to be slightly modified to operate with one of the 87C054 s timer counters The technique is often called bit banging The Computer Applications Journal and has the advantage of saving some hardware if you can afford the neces sary time required of the software NETWORK PROTOCOL PROCESSING As indicated earlier in addition to the serial interface software you need code that handles network message formats The code starts by waiting until either a or an 1 is received either of which indicates the start of a network message then the entire message is stored in a buffer Once the carriage return
199. t c49 i tuf Burst Gate PAL NTSC Select R43 3 5874 43 INJECTION 12 o5 a 2nzz22 R48 ik cS4 1OuUF LOCAL Local video to Video Mux Figure 4e Encoding the RGB data into baseband video is accomplished with an LM1886 which contains three DACs and an LM1889 which accepts the regenerated chroma subcarrier modulates the R Y and B Y signals and produces baseband video an additional constant phase shift to the injected carrier The phase shift network and amplifier consisting of the Q3 and Q4 stages compensate for these fixed phase delays This ciscuit provides an output whose phase is adjustable by means of variable capacitor C48 and has a tuning range of approximately 0 to 160 of phase shift For a given input signal amplitude the output signal amplitude is constant regardless of the phase shift introduced The output of this circuit is the signal injected into the LM1889 circuits CONNECTING TO THE HCS II Now that you have a working terminal circuit for overlaying text onto live video you still need to connect it to the HCS II network In order to do this you will need a serial interface compatible with the net work some software that handles network message formats and soft ware that interprets network messages and creates responses or actions or both to those HCS II network mes sages This particular design includes both an RS 232 and an RS 485 inter face U1 a MAX232 provi
200. t are kind of noisy Utilize 8 optically coupled inputs You can also take advantage of 16 programmable I O lines 6 timer counters and 4_ serial 485 ports But wait there s more Add epee eg ony Ty the EPAC 3000 G2 can handle just about anything The Is ju MAc inc 618 529 4525 FAX 61 8 457 0110 P 0 BOX 2042 CARBONDALE IL 62902 PTY NAATO NEWS SOLID STATE DISK SYSTEM FEATURES REMOVABLE MEMORY CARD The MNC 1150 with a 16 bit data high speed solid state path In addition disk system features a eight 32 pin JED EC removable PCMCIA 2 0 sockets for SRAM memory card slot for ISA EPROM EEPROM and FISA computers The and flash memory M S LXX compatible chips are provided system stores files in fast for a total storage capacity unloaded while the com Evaluation units are semiconductor memory of 72 megabytes It has puter system is operating available for 295 with rather than mechanical been designed with CMOS Dual battery backup is zero memory disks to achieve the high technology using a versatile provided for the JEDEC speed without wear The register based interface with sockets when SRAM is MNC International Inc on board BIOS ROM error sensing and selectable used On board flash 2817 Anthony La South allows instant on and interrupts to ensure data memory programmer and Minneapolis MN 55418 instant reset capability integrity in critical environ support software is pro 612 788
201. t releases the counter reset when the clock pulses begin At the conclusion of the scan reset will reassert when the one shot times out Use to your advantage the selec tion of the key at row 0 column 0 at counter reset in systems that include a self power down capability Here you may realize this circuit in CMOS to reduce current usage and run it off the RAM backup power The active key can be used as a power button provid ing the stimulus to the power control circuitry to return the system to a powered state Just make sure you properly isolate the data line so as not to backfeed the unpowered key input port pin The nice thing about this three wire interface is in principal it can be extended to service fairly large key boards I ve gone as high as a hundred keys You may have to use larger decoder and multiplexer chips but as far as the firmware is concerned all you do is increase the terminal value forKEY COUNT in the contact scan loop and provide a larger lookup table At the other extreme you may be faced with interfacing a keyboard that has connections to each contact with a single common The electrical inter face of course is trivial you just bring all the keys in on individual port pins You re all hooked up and at first a key scanning algorithm may seem unnecessary but you re still faced with performing the fundamental keyboard functions Figure 4 shows that the basic algorithm still holds
202. te EEPROM for non volatile data storage 7 line relay driver 32K SRAM for up to 62K pseudo EPROM capacity Development Software MICRO C 52 C compiler featuring 5 memory models and a standard library with extensions to control BD52 s hardware features ASMS2 cross assembler PC hosted control debug software with easy to use windowed interface that provides access to all of the BDS2 s features Order a BDS2 at the introductory price of 199 95 US from please add 10 00 for liming Dunfield Development Systems P O Box 31044 Nepean Ont Canada K2B 8S8 Phone 613 256 5820 moment when garbage appeared on the screen but it was only a reflex because I d already anticipated the doubling of all the chip s baud rates timer con stants and so forth I calmly switched my terminal software from 9600 to 19200 baud and voilh Exercising my test program discovered the board worked pretty much as expected i e it would work with a single memory wait state tried zero wait states knowing that chips are often faster than specified especially at room temperature but the EPROM couldn t hack it Take it easy on your cargo with a custom Cabbage Case built to the exact dimensions of pour equipment Take it easy on your back with our extension handle and tilt wheels options Take it easy on your wallet Let Cabbage Cases show you how easy itis to Save money on quality custom built road cases that make Shipping and tra
203. ter All Tempustech VMAX products are PC Bus Compatible Made in U S A 30 Day Money Back Guarantee Qty 10 Ok Call for Quantity Pricing reg bl ue ae TEMPUSTECH INC TEL 800 634 0701 FAX 813 643 4981 Fax for 295 Airport Road fastresponse Naples FL 33942 136 The Computer Applications Joumal Issue 29 October November 1992 57 In the extended HLS mode each cone is converted into a cylinder Now when LIGHTNESS goes from 0 to 1 the colors don t get washed out Black and white occur only when saturation is 0 In effect an increase in the number of colors possible given by the ratio of the volume of a cylinder to that of a cone has been realized This ratio of 3 means an additional 174 762 colors for the VGA without any loss of concept In fact the only change to the code in Listing 2 needed is to define sat Oas 1 or better yet leave it out altogether SOME EXAMPLES Having color defined in an easy to understand and dimensionless coordi nate system means that not only can a single color be defined easily usually on the first try but that a complicated color spectrum from shocking pink to pastel green can be defined with simple analytic functions Listing 4 shows several examples that illustrate the compactness of code needed to define an array of colors and the versatility of the HLS modd Example 1 traverses all the colors of the rainbow in pastel shades To achieve the pastel
204. the same way To make the use of the device registers clearer added the simple macro define SREG x unsigned Cunsigned x c gt com_base that generates the address of the device registers This way because c gt com_b a seis defined in the program context the address of any device register is simply its offset the de f i n ed value plus the base So you will see things like val inp SREG LCR This code reads the L C R register using SR E G to generate the address and thei n p function to read this address With this step out of the way you can look further into initialization The first step is to set the data rate parity and number of bits per word To do so used the Quick C function _bios_serialcom Usingthis function was simpler than actually setting the bits in the registers If your C does not have it writing an equiva lent function is quite easy using the data sheet The ring buffers are allocated in the next step Using the C memory allocation functions allows you to have variable size buffers and to have them created when you initialize the serial I O port This feature makes the SERCOM package more general How these ring buffers work and are used is detailed in the next section Output a character Output a string Get a character Get a string Check for a character present in the input buffer Test for NEWLINE terminated string in the input buffer Clear the input buffer
205. then use an ECL to TTL converter so that everything after the converter is TTL CMOS logic inter leave the slower CMOS memory to achieve the desired sampling rate You will find that CMOS memory is much cheaper if you require deep memory 3 If you only need 100 MHZ consider using the FINALLY A Universal Tool for the Firmware Developer More flexible than any Microprocessor ICE PROMICE doesn t use a microprocessor pod and handles any word size 8 16 2048 bits More versatile than intrusive ROM based debuggers PROMICE doesn t use your target system s O resources yet allows you to debug firmware contained in ROM More powerful than simple ROM emulators PROMICE provides complete source level debugging and full memory control PROMICE The Universal Firmware Development Tool Grammar Engine Inc 921 Eastwind Dr Westerville OH 43081 Tel 614 899 7878 Fax 614 899 7888 TAO Cn 171 98 issue 29 October November 1992 The Computer Applications Journal Analog Devices AD9058 It has two matched 8 bit 50 MHZ ADCs on one chip with TTL outputs Simply send your analog input into both of the ADCs and clock them out of phase you will have your 100 MHZ system without any ECL logic Cypress has CMOS memories that will store data at 50 M Hz so you won t have to mess with interleav ing The AD 9058 is about 55 in 100s 4 If you don t want to bother with repetitive sampling you might want to check out
206. tness the ability to handle unreliable data hope to implement a form of fuzzy logic in the future to deal with the tendency of the data rather than rigid rules of traditional logic 10 PERFORMANCE OF THE SENSOR I conducted several tests to determine operational limits of accuracy repeatability and speed Tests showed a minimum of 0 22 mm for object size measurements Average position measurenent errors in the x and y dimensions were 0 07 mm and 0 mm respectively Measurement time was 11 ms demonstration program Finally the sensor had excellent repeatability and a greatly reduced power drain including a single 5 volt supply compared to the first circuit The component cost was 476 76 An insertion performance of over 98 of cuttings is projected The sensor has added some other benefits as well It can detect the proper grasp of a cutting REFERENCES 1 W L Whittaker G Turkiyya M Herbert An architecture and two cases in range based modeling and planning IEEE 1987 2 W Simonton Automatic plant handling and processing in a robotic workcell Transactions of the ASAE 1990 3 W Simonton Issues in robotic system design for transplant production systems Interna ivici tional Symposium on Transplant tronics Division 1990 production Systems Yokohama 9 S Ciarcia Let your fingers do the Japan 1992 talking August 1978 BYTE 4 W Simonton B Farmer Sensor 10
207. tors The amplifiers serve as isolation amplifiers between the video card and the monitors by the isolatable charac Photo 1 Driving mu tip e monitors from a single VGA display adapter doesn t have to be expensive The Computer Applications J ournal Issue 29 October November 1992 61 teristics of an emitter follower sr A a amplifier As mentioned above the PC i i PJJ video card only sees 75 ohms of load es a ae e a ie resistance no matter how many bases a orl Tilt ereen connect in parallel at this point The ia FEH m MES emitter of each transistor follows the on er IL a voltage leva of its base which makes ort al the emitter circuit the signal source to the monitor connected to it At this Te point the signals are directly derived from the video card The emitter follower circuit provides load current that drives the monitor inputs This drive current is provided by the collector emitter drcuit and does not require any significant level of load current from the base circuit Therefore you can use this circuit to connect multiple monitors without affecting the load current the video card must supply The combination of all of these simple factors allows this circuit to operate If you need more monitors UGA Out simply connect more transistors base Master leads to the 75 ohm resistors Then just build the same core over again for each monitor 6800
208. truction the software was trying to talk to I O ports including the console port that weren t there anymore Changing the OUT instruction from 3FH to 1FH skipped the dramatics and hitit I experienced an apprehensive Al4 RO TXS UL HD64180 gt p DREQON Senne F NMIN 3 RN BREN BACKS HALTS DREQIN AB INT2N INTIN IORQN TENDON lopment system Introducing the BD52 a complete 8052 development system providing all hardware and software needed to develop 8032 8052 based products A flexible embedded controller with pseudo EPROM apabilities allows you to download and teat your code for easy software evelopment Memory and interface extensions enhance the BD52 s apabilities A PC based windowed interface gives you complete control f software and hardware functions The powerful development tools nclude a fully featured assembler C compiler and debug monitor oftware and hardware are closely integrated for greater productivity at n extremely competitive price 8052 deve Hardware 5032 microcontroller and EPROM loaded with debug monitor ability to address 64K of code space and 64K of data space pseudo EPROM capacity 30K with 32K SRAM included RS232 serial interface 11 parallel I O lines 120V AC power supply documentation and schematics sockets for extensions watchdog amp power monitor 4 A D amp 1 D A converters 512 by
209. ude but also influences the phase relationships of the frequency components in the transmitted waveform The TDR is forced to consider this fact when computating termination resistance Ultimately this real life effect limits the length of cable the TDR can test HUMAN INTERFACE We imagined how the TDR would be used and attempted to build the instrument around those purposes The TDR had to have a simple inter face and a small package Simply stated the number of basic actions required to operate any instrument or appliance should be as few as possible Because nearly anyone can memorize three or four operations to perform some function we restricted the number of keys on the TDR to three and let the software handle the rest With the above goals in mind we decided to make a touch screen interface That would allow us to 26 Issue 29 October November 1992 present three buttons on the display and let the operator select one with the point of a finger It also allows us to add features later by simply chang ing the firmware For our design the best combina tion of keys was two for moving through menus and one for selecting an option We ensured that any func tion or operation in the TDR would be compatible with the three key inter face which unfortunately meant we would have to anticipate any param eter that eventual users may wish to enter and incorporate into the menu CABLE TYPES Computer networks can
210. uses time domain reflectometry techniques to measure length and calculates the actual termination impedance based on the amplitude of the reflected waveform It has a measurement range of approxi mately 1800 feet and handles 50 and 75 ohm characteristic impedance cables primarily RG 58 and RG 59 used in thin wire networks The hardware combines an 87C5 1 microcontroller with a 4line 20 character LCD display an infrared three key touch screen interface a low power PAL a dual 8 bit DAC a very high speed comparator and a handful of digital and analog jelly beans to bring it all together The software consists of approxi mately 3K of 805 1 assembly language which indudes a flexible menu system a custom integer math package and the actual measurenent code A 9 volt battery powers the unit which features automatic shutoff and it is packaged in a2 x 4 x 6 plastic enclosure We also kept the bill of materials below 200 THEORY OF TDRS The TDR capitalizes on the traveling waveform s characteristic of reflecting some portion of its power as it passes through the interface of two dissimilar materials A detailed understanding of why these reflections occur requires more space than have However will cover the theory necessary to build the TDR which centers on how electromagnetic waves propagate down a transmission line Figure Some vectors and differential calculus help show how the time domain
211. ve TIFF PCX GIF TGA bin Work with large images in expan d or exten dmem Powerful grayscale and color image processing brightness contrast sharpen outline linearize overlay matrix convolution rotate resize etc Color reduction 24 bit to 256 or fewer colors display super VGA images on EGA Control ScanJet scanner Print image at any size on lager printer Display on EGA VGA super VGA up to 1024 x 768 256 colors or 200 x 60O 32K colors vvv vvv v Callor fax to order 314 962 7833 VISA MC COD Victor Image Processing library 195 Victor Image Processing Library with IDEC 512 x 512 frame grabber 499 Ca tenary Systems 470 Belleview St Louis MO 63119 voice fax 314 962 7833 Victor irage Processing Library supports Microsoft ad Bor and CiC compilers Ne royalties Source code available 173 Issue X29 October November 1992 99 The Computer Applications Joumal SOS TIME various size registers But if you d rather do it in analog you might consider a back biased diode eg a zener diode capacitively coupled to an amplifier You won t find that the spectrum is flat from DC to 5 kHz but you can wave shape it with filters as required Msg 59074 From NELSON CHANE To RUSS REISS Thanks for the tips heard from one manufacturer NoiseCorn that they make noise generators for the RF and microwave industry can use a noise diode that they produce and capacitively couple to an op amp as you
212. veling with your valuable cargo safer and easier Prices quoted over the phone Call 8004884495 today e 1166 C Steelwood Rd GAB GE Columbus OH 43212 GASES 800 888 2495 614 486 2495 FAX 486 2788 157 The Computer Applications Journal Issue X29 October November 1992 83 I left Zilog happy that despite human error the cause of most computer problems had suc ceeded H owever even as was driving away that one remaining wait state started to gnaw at me CHIPS IN THE FAST LANE Zipping down the freeway I pondered the problem Yes state of the art memories exist but where can I get one Those puppies aren t exactly a stock item at the local Ye Old Chip Shoppe On autopilot registered the red lights stacking up ahead and dove for the off ramp planning to take one of the secret short cuts that harried Silicon Valley commuters seek out like rats in a maze Though am skeptical of psychic phenomenon wonder if it was just coincidence that my roundabout path took me right by WaferScale Integra tion Hey didn t just get something in the mail from these folks about fast EPROMs TIRED OF WAITING FOR THE PROMPT Speed up with a ROM DRIVE Boots DOS and programs instantly Also used to replace mechanical drive completely in controllers or diskless workstations The only perfect protection from viruses Easy to install half size card MVDISK1 G4k 75 MVDISK2 360k
213. w count in the high order byte Because the 8031 timers count upward the time values must be two s comple to 8031 TL input mented 0123 hex becomes FEDD Finally to allow a simple D N z loop the number of timer wraps is increnented Once the data is ready the code simply fetches each time value loads the two low bytes into the timer starts it and counts down the number of timer wraps found in the high byte As mentioned before the recording and playback loops have similar overhead so the time lost in the former is made up in the latter That s all there is to it WELL ALMOST The good news is that the IS 1U60 responds to nearly any modulated IR signal regardless of carrier frequency as long as you hold the remote within a few inches of the receiver s lens Remember that the 38 kHz bandpass filter decreases sensitivity for off frequency signals but if you have enough firepower it doesn t matter how bad the response is The bad news is that the IS1U60 also responds when hit with singleton Listing 2 This section of code from IRSAMPLE C captures he raw IR input signal from We circuit shown in Figure 4 and stores ifin Extemal RAM atthe address formed by P2 and RO MOV INC MOV MOV A HIGH IRBuffer A P2 A RO FF 71 RWai t IR_INPUT IRWait C IR_INPUT A C IR_INPUT A C IR_INPUT A C IR_INPUT A C ER_INPUT A C IR_INPUT A C IR_INPUT A C IR_INPUT A MOVX ROJ A
214. ws the highest to the lowest pair to match with the M SB to the LSB in on board RAM and also follows the high to low order SPI format Only one pair is energized at any one time If any of the beams within these 80 pairs is obstructed the output of U26 will go high for the respective pair according to the threshold set by R1 A high or low will be loaded into the SPI port for all pairs blocked or unblocked respectively 9 When the MCU provides the stepping clocking se quence for the final pair one extra count is clocked in order to deactivate all pairs to lessen power drain during idle time Both sets of serialized signals are read from on board RAM and object position is calculated and sent to the parallel serial output THE SOFTWARE My MC68HC 11 configured with pin PEO to ground and jumper J1 allows RS 232 sensor to PC software Listing 1 A demonstration program shows what s involved in dealing with the positon sensor kak 68HCII Regist wk kkk er Equates 1003 1004 1007 1009 1028 1029 102A Buffalo 3 2 Eauates and Jump Table adr PORTC EQU PORTB EQU DDRC EQU DDRD EOU SPCR EQU SPSR EQU SPDR EOU kkk kkk USTACK EOU WARMST EQU RRR RAM VARI ABLES RK 547 FF7C ORG 50001 DAIO RMB 1 DAY RMB 1 DAS RMB 1 DAT RMB 1 DAG RMB 1 DA5 RMB 1 DA4 RMB 1 DA3 RMB 1 DA RMB 1 DAL RMB 1 ORG s0100 kkkkk START kkkekk Register Initialization LDS USTACK LDAB 00 LDX 000A

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