Daughtercard User Manual (PDF format)
Contents
1. By Craig Johnson AAOZZ AA ZZ CBJOHN COM www cbjohn com AAQZZ oe et oe ot Te WWM HOU esses cctanrescecraastecescendvaeteerateiatecesne 2 Hardware Descnpton 2 1 Circuit Description ssesesesssseeesereeeee 2 2 Daughtercard with PIC EL Board 2 3 Daughtercard In Stand alone Board 3 1570 Daughtercard Assembly 00 3 1 Parts VASMUTICALON ccxieidentoeepaesesntneesereouens A ASSCMDIY E 4 PEgen570 Software Application 000000 4 1 Pa DG Te d Band Tales cicssecscasascnaseccaccanteddonsassaseeanica 4 3 S1570 EIERE regen 4 4 User Interface isssccacasscacanssontsscasccdenssenseces 4 5 MENU gerett 4 5 1 Sideband Selection ccssccesseeeee 4 5 2 CW Sidetone During Receive 4 5 3 Frequency Division for LCD Display 4 5 4 FSK Frequency Shift 5 csssccesseeees 4 6 LCD DIG ONY a teure eerste Appendix A Schemanc Appendix B Parts List EEN AAOZZ Si570 Daughtercard v1 6 July 12 2011 1 Copyright 2011 AAOZZ Appendix C 1570 Dauightercard Parts Placement 12 006 scesccscosssseeecsessscessccuseceasseevensenenscranseanaesnsncescsnnssens 11 Appendix D 1570 Daughtercard PC Bospdteueegetteeesgeeggeegkeke degen 12 1 Introduction This Daughtercard uses the Silicon Labs i570 DSPLL and software to generate RF signals in the continuous range of 10 to 157 MHz Since many amateurs use divide by four mechanisms in Quadrature Sampling Detect2. 0 26 0 26 SECHER ES M 161 3507 E 0 53 0 53 z Sage 1 2 001 uF eerste cap axial____ D 1116PHCT ND_ TC 0 08 0 08 3 LG c3 c5 10 uF tantalum cap D 399 3638 ND_ sam sa 4 Kn ikresistor 1 8w 5 otmen son 1 U3 9870 CMOS 20ppm 10MHz__ Silicon Labs 570CBC000107DG_ 1 U1 REGLDO1A5 0V SOT223 3 D ZLDO1117G50DICT ND_ 1 U2 REGLDO1A3 3V SOT223 3 D ZLDO1117G33DICT ND__ 2 Qna2 BS 170N chan MOSFET oi BS170 ND 1 HDR2__ pinheader 0 1 2x2 pos n 2 forHDR2 shunt 0 1 2 pos n msenonp _ Tor DC 22 Insulaed Hookup wire n P D A3051B 100 ND or similar cable 3 colors 7 each PIC 16F88 programmed D Merde with AAOZZ software Poa o Pe JA supplied AAOZZ Si570 Daughtercard v1 6 July 12 2011 10 Copyright 2011 AAOZZ Appendix C Si570 Daughtercard Parts Placement AAOZZ Si570 Daughtercard v1 6 July 12 2011 11 Copyright 2011 AAOZZ Appendix D Si570 Daughtercard PC Board oo cco Oko D Gi AAOZZ Si570 Daughtercard v1 6 July 12 2011 12 Copyright 2011 AAOZZ
3. Paddles connection 4 PEgen570 Software Application My sample application software for the AA ZZ Si570 Daughtercard is called PEgen570 It runs on a simple inexpensive 16F88 PIC in the PIC EL board As explained in Section 2 2 the daughtercard uses an external cable to communicate with the PIC EL board AAOZZ Si570 Daughtercard v1 6 July 12 2011 4 Copyright 2011 AAOZZ 4 1 A 16F88 PIC There are several reasons why the 16F88 is used for this application instead of the PIC EL standard 16F628A 1 Compared to the 16F628A the 16F88 has more than twice as much FLASH memory for program instructions 50 more data memory for variable storage and tables and twice as much EEPROM memory non volatile storage 2 The 16F88 has an 8 MHz internal oscillator while the 16F628A has a 4 MHz internal oscillator The extra speed is nice 4 2 Band Tables The software is implemented to use 24 frequency bands Most of the parameters that the Si570 requires to produce the desired output RF signal are in tables in program memory The program memory tables cannot be modified with program instructions These tables are used by the application with the band number as an index One table is located in the PIC s data memory and can be modified This table is loaded from EEPROM upon power up This table consists of 24 entries with each entry containing a starting frequency requiring 4 bytes This means that the 24 band table requires 96 byte
4. for static protection reasons Here is a possible assembly order that works well if you have a PIC EL board 1 Install the two voltage regulators U1 and U2 Be sure you distinguish them properly and install them in the correct locations 2 Install the resistors and the capacitors 3 Install the header connectors HDR1 and HDR2 4 Test the voltages coming out of the voltage regulators AAOZZ Si570 Daughtercard v1 6 July 12 2011 3 Copyright 2011 AAOZZ a Plug into PIC EL board and power up b Use a Volt meter to check o 12v coming into HDRI1 pin 8 o Svoutof Ul Check at point where regulator connects to C3 o 3 3v out of U2 Check at point where regulator connects to C5 o IF ANY OF THESE VOLTAGES ARE NOT CORRECT YOU MUST RESOLVE THE PROBLEM BEFORE PROCEDING 5 Install the Si570 Be sure to align the dot on the Si570 with the 1 on the PCB Center the Si570 on the pads and apply a small amount of solder to one pad and Si570 connection point Then before soldering the other connection points check the alignment of all 8 connection points on the pads Reheat and reposition the Si570 on the pads if necessary Then solder the remaining 7 connection points There three connection points on each side and one on each end 6 Install MOSFETs Q1 and Q2 Orient per the silkscreen markings on the PCB 7 Install the stereo phone jack J1 8 Construct the jumper assembly with 2 or 3 wires One from tip to tip and the oth
5. that it operates with two communications lines However the communications scheme used by the S570 is I2C and that means the lines are both bi directional This presents a problem for the PIC EL since two of the three PIC lines that go to the Daughtercard interface are also shared by the LCD and the other line is shared with the programmer This sharing of pins prevents two way communications via DC with these lines The workaround is to use an external cable to connect the daughtercard to the PIC EL s paddle jack The paddle jack connects to different PIC pins and these pins are only shared with PIC EL Pushbuttons 2 and 3 These two pushbuttons cannot be used when operating the 1570 daughtercard but otherwise the lines work well for DC communications 2 3 Daughtercard In Stand alone Board See Control Board manual 3 Si570 Daughtercard Assembly 3 1 Parts Identification The builder should first identify all the parts in the kit The parts are listed and described in Appendix B Every effort is made to include all parts in the kit however mistakes do happen If you are missing a part notify Bill Kelsey at Kanga and he will send the missing parts to you It may be faster to get common components from your own junk box or at your local Radio Shack store 3 2 Assembly The silk screen part names on the board will be your guide The order in which you place the parts is not critical but I would suggest that you install the MOSFETs last
6. 2 36 41 MHz 18 81 90 MHz 11 12 MHz 21 23 MHz 13 41 47 MHz 19 90 101 MHz 12 13 MHz 23 15 MHz 14 47 54 MHz 20 Kee 3 13 15MHz 9 25 28MHz 15 54 61MHz 21 Te AAOZZ Si570 Daughtercard v1 6 July 12 2011 5 Copyright 2011 AAOZZ 15 17 MHz 10 28 32 MHz 16 61 70 MHz 22 e 17 19 MHz 11 32 36 MHz 17 70 81 MHz 23 See 4 3 Si570 Calibration The PIC s Si570 band tables described in Section 4 2 are pre calculated with the nominal value for the i570 s internal crystal frequency 114 285 MHz The table entries combining the crystal frequency with other parameters needed to generate RF in that frequency range are stored in the PIC s EEPROM and are loaded into the PIC s volatile memory at power up This nominal frequency is almost never perfect of course but the i570 is calibrated in the factory to use corrected parameter values to produce the default start up output frequency of exactly 10 0 MHz Other Si570 part numbers use different start up frequencies By holding Pushbutton 3 down during power up the application is directed to retrieve the parameters from the Si570 s non volatile EEPROM memory The software then does a reverse calculation to find the actual Si570 crystal frequency as determined by the factory to produce 10 0 MHz After the actual crystal frequency is determined the table entries are recalculated and copied back to non volatile EEPROM When Pushbutton 3 is r
7. 3 for longer than 2 seconds stores the current frequency in EEPROM This frequency is used as the start up frequency on subsequent power ups 4 5 Menu A simple menu is used for changing 3 items in the operation 1 Sideband selection 2 Frequency division for LCD display AAOZZ Si570 Daughtercard v1 6 July 12 2011 6 Copyright 2011 AAOZZ 3 FSK enable if FSK is enabled via compile option in source code The menu is activated by holding Pushbutton 4 while pushing Pushbutton 3 and then releasing them both The current mode is shown in character position 1 of line 1 of the LCD Now the user can update the current selection of each of the three items Tapping Pushbutton 3 allows the user to cycle through the available options for the current item Tapping Pushbutton 4 leaves the current item at its last value and advances to the next item in the menu After the last item has been selected pressing Pushbutton 4 exits the menu 4 5 1 Sideband Selection The first menu item that may be selected in the menu is the sideband selection The user may select one of four sideband modes USB LSB CW or CW An external latching relay is engaged or disengaged as the sideband is changed in the menu PIC output ports RA6 and RA7 attach to HDR5 and HDR6 pins 15 and 16 respectively As the sideband is changed in the menu either RA6 or RA7 is driven high with an 8 mS pulse with the opposite side being held low to engage or disengage the external
8. e the parameters from the nonvolatile memory and calculate the calibrated crystal frequency This actual crystal frequency can be used in subsequent calculations and the results will much more accurate than it would be if the nominal crystal frequency was used The Daughtercard can be used in a platform of your choice but here are a couple of examples 2 1 Circuit Description The schematic is shown in Appendix A Since the PIC runs at 5v and the i570 runs at 3 3v signal level translation circuitry is necessary Much of the circuitry on the board exists to do this translation At first the problem seems trivial to solve but since it must be bi directional it is not quite that easy At first glance the circuit is quite elegant in its simplicity but when it is looked at closely it is a little more complicated The design is not original to me but is described in many I2C specifications The Daughtercard has two voltage regulators One converts 12v to 5v and the other converts 5v to 3 3v Why not just bring 5v from the PIC EL Two voltage regulators are used because the PIC EL header is connected to 12v for the DDS 60 and I didn t want to rewire the PIC EL for the new Daughtercard The Daughtercard has two RF output paths from the SI570 to the headers even though the CMOS version of the Si570 which we use for the Daughtercard only has one output CLK on HDR3 The second RF path CLK on HDR4 is there in case a different version of the Si570 is u
9. eleased the PIC restarts and populates the tables with the newly calculated values 4 4 User Interface The user interface for the PEgen570 application is very simple It uses two pushbuttons an encoder and a 2 line by 16 character LCD The Reset pushbutton on the PIC EL board is configured via the CONFIG statement in the source code such that it does not perform a microprocessor reset when pressed but to operate as a normal I O pin instead This made the pushbutton available for operation and it is needed To clarify this change in usage the pushbutton will be referred to as Pushbutton 4 rather than the Reset pushbutton This means that the 9PIC EL board must be powered down and up after loading new software into the PIC before the new program will start executing Simply moving the slide switch from PGM position to RUN position does not start the program The Pushbutton 3 and Pushbutton 4 are the two operational pushbuttons When running the S1570 each time Pushbutton 3 is pressed and released the tuning digit that is currently being modified by turning the encoder to be increased by one digit It can be advanced up to the 1 MHz position Similarly each time Pushbutton 4 is pressed and released the tuning digit that is currently being modified by turning the encoder to be decreased by one digit The digit that is currently being modified by the encoder is underlined When the daughtercard is running pressing and holding Pushbutton
10. equency divided by two or four The divide by four option is useful when the signal generator is being used as a signal source for a QSD QSE Tayloe mixer The circuitry for these mixers usually divides the input frequency by four so this software option allows the LCD to display the mixer s operating frequency Tapping PB3 while in this portion of the menu allows the divide by x factor to be changed When the correct factor is selected press PB4 to advance to the next menu item selection 4 5 4 FSK Frequency Shift This menu item is only available and displayed only if the FSK option is enabled via a DEFINE statement in the source code The default software does not have FSK enabled Tapping PB3 while in this portion of the menu allows the FSK option to be enabled or disabled When the correct factor is selected press PB4 to advance to the next menu item selection AAOZZ Si570 Daughtercard v1 6 July 12 2011 7 Copyright 2011 AAOZZ If FSK is enabled the FSK shift size will be used even if CW or CW is also selected in the menu FSK takes precedence When FSK is active Header HDR7 attached to PIC input port PB7 is monitored by the software to determine whether or not to shift the frequency by the FSK shift size The frequency is set to the displayed frequency when the signal on HDR7 is HIGH the MARK frequency and is shifted down by 170 Hz when the signal on HDR7 is LOW the SPACE frequency The software looks at the si
11. er from ring to ring A ground connection wire is optional 9 Plug Daughtercard into PIC EL board 10 Optional Software is not necessary for Si570 to generate RF at the Si570 default frequency of 10 0 MHz If you have a frequency counter or a receiver that can tune to 10 0 MHz power up the PIC EL and verify that you have an RF output signal at 10 0 MHz If not stop here and find problem before installing the PIC If you don t have a PIC EL board apply 12 volts to HDR1 pin 8 ground to the HDR1 pin 5 and look for the 10 0 MHz output on HDR1 pin 6 11 Plug one stereo plug of jumper cable into the J1 of Daughtercard and the other jumper cable stereo plug into the Paddles jack of the PIC EL board J3 12 Put the 16F88 PIC in 18 pin PIC socket of PIC EL 13 Program the 16F88 per PIC EL instruction manual 14 Switch the PIC EL board PGM lt gt RUN switch to RUN 15 If you are using the AA ZZ Si570 Signal Generator software you MUST REMOVE THE 12v POWER FROM THE PIC EL BOARD AND THEN RESTORE THE POWER AGAIN This is important since it reinitializes and restarts the PIC program after programming NOTE THAT THE PIC EL RESET BUTTON DOES NOT START THE PIC PROGRAM since the Signal Generator program configures the PIC to use the PIC EL RESET button as a functioning pushbutton instead of as a PIC RESET The Signal Generator needs this button since two of the other three pushbuttons co opted for use by the I2C communications via the
12. gnal on HDR7 often enough to detect and change the frequency within 1 6 mS of HDR7 changing state 4 6 LCD Display The first line of the LCD displays the current frequency The second line is for debug purposes and shows the hex digits for the 6 1570 register parameter SiReg7 through SiReg12 starting at LCD position 1 The current band number is displayed in positions 15 and 16 of line 2 As explained in the Menu section regarding the frequency division selection option the PEgen570 application can be configured to display the current Si570 frequency or it can be configured to display the Si570 frequency divided by two or four The divide by four option is useful when the signal generator is being used as a signal source for a QSD QSE Tayloe mixer The circuitry for these mixers usually divides the input frequency by four so this software option allows the LCD to display the mixer s operating frequency AAOZZ Si570 Daughtercard v1 6 July 12 2011 8 Copyright 2011 AAOZZ Appendix A Schematic PIC EL Paddle Jack PIC RA3 DATA PIC RA4 CLK cable Stand alone PIC EL CLK PIC RA4 RB 7 unused DATA PIC RA3 RB2 unused 4 PIC NC RB3 unused GND AAOZZ Si570 Daughtercard v1 6 July 12 2011 i570 Daughtercard Ver 4 6 7 18 2011 c6 c7 T 1uF in Copyright 2011 AA0ZZ Appendix B Parts List Si570 Daughtercard Parts Ver 13 12 28 2010 1 HDR1 8 pinRAHeader_ _ Samtec TSW 108 08 F S RA
13. latching relay The recommended latching relay TQ2 L 5V DigiKey part 255 1004 5 ND requires 14 mA at 5v for 3 mS plus contact bounce time The latching relay is intended to enable the proper I and Q phases of the transmitter and or receiver to set the proper sideband 4 5 2 CW Sidetone During Receive If the mode is CW or CW Header HDR7 attached to PIC input port PB7 is monitored by the software to determine whether or not to shift the frequency by the sidetone amount HDR7 is expected to be set to a low state by external Transmit Receive circuitry during Receive operations and to a high state during Transmit operations The software continually monitors the signal at HDR7 and when is detected to be low while in CW mode shifts the frequency down by 600 Hz from the nominal displayed frequency If the mode is CW and HDR7 is LOW Receive the frequency is shifted up by 600 Hz from the nominal displayed frequency In either case whenever HDR7 is detected to be HIGH indicating Transmit operation the frequency will be set back to the nominal frequency that is displayed on the LCD How fast does it switch The software looks at the signal on HDR7 often enough to detect and change the frequency within 1 6 mS of HDR7 changing state That s fast enough for QSK 4 5 3 Frequency Division for LCD Display The PEgen570 application can be configured to display the current Si570 generated frequency or it can be configured to display the Si570 fr
14. ors QSD i e Tayloe mixers for their receivers and also in Quadrature Sampling Exciters QSE for their transmitters the 1570 Daughtercard can provide the local oscillator signal for receivers and transmitters which operate on the 80 through 10 meter amateur bands 2 Hardware Description The i570 DSPLL programmable frequency synthesizer is a relatively new technology developed by Silicon Labs The Si570 offers some advantages over the DDS parts that have been used in applications in the past years Two advantages are greatly reduced power consumption and the clean output without DDS byproducts spurs Silicon Labs offers several versions of the 1570 with different output options and frequency limits The version used in the Daughtercard is a CMOS part with a 10 0 MHz default frequency and a 160 MHz maximum frequency The upper limit implemented in the PEgen570 application is 157 MHz The internal crystal of the Si570 runs at a nominal 114 28 MHz However the crystal in any individual part will not oscillate at exactly this nominal frequency Since the the crystal frequency is used in the frequency parameter calculations in the software the deviation from nominal means that the frequency the Si570 generates will not be accurate Fortunately Silicon Labs calibrates each individual part and saves the parameters in its nonvolatile memory to cause it to start up at the default frequency in this case 10 0 MHz The software can retriev
15. s of memory Since the maximum size of any single bank of data memory in the 16F88 or any 16F PIC for that matter is 96 bytes This determines the maximum number of bands that can easily be handled in the PIC With additional overhead the size could be expanded and then the upper frequency could be increased However the CMOS version of the 1570 the version that the Daughtercard is designed to use has a maximum frequency of 160 MHz This means the current 96 byte table with an upper limit of 157 MHz is sufficient for this 1570 version The lower limit of the Si570 is 10 MHz and the 96 byte table also handles this limit The 24 PEgen570 bands were created by examining the Si570 spec sheet and making calculations with a spreadsheet based on the Si570 parameter requirements Without getting into the esoteric requirements of the Si570 frequency generating parameters and the formula involving several specific multipliers the Si570 internal crystal frequency and the desired output frequency the frequency range of each band was calculated The table was generated in such a way that the major parameters for each band can be pre calculated and retrieved from tables when changing frequency This greatly minimizes the number of complex calculations that must be done for each frequency change The 24 PEgen570 bands are defined as follows Frequency Frequency BAND Frequency BAND Frequency Range Range Range Range 10 11 MHz 19 21 MHz 1
16. sed in the future The CLK signal is also routed to the 8 pin connector HDR1 so the PIC EL s RF jack is usable AAOZZ Si570 Daughtercard v1 6 July 12 2011 2 Copyright 2011 AAOZZ Other versions of the S1570 have higher frequency limits but with reduced amplitude output The spec sheet for the CMOS version says it operates between 10 to 160 MHz but some users report it can be used between 3 5 and 240 MHz The upper limit implemented in the PEgen570 application is 157 MHz Header HDR2 is a 2x2 connector block that is not used when the Daughtercard is used in a PIC EL However when the Daughtercard is used in a different platform two jumpers can be installed in this header block 1 to 2 and 3 to 4 to route the DC communications through the 8 pin interface connector This eliminates the need for the external wires from the stereo jack to the platform 2 2 Daughtercard with PIC EL Board One platform for the Daughtercard is the AA ZZ PIC EL board The PIC EL board is available from Kanga at www kangaus com See details on my web page also An AA ZZ Signal Generator sample application for the PIC EL is available so it is very convenient if you want to experiment with the software The i570 Daughtercard was designed to fit into a socket on the PIC EL board that was originally designed to accommodate a DDS 30 or DDS 60 Daughtercard from AmQRP The DDS Daughtercard operates with three control lines The Si570 Daughtercard is simpler in
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