SAPIC-E Small Alphanumeric LCD Controller User`s Manual
Contents
1. 80 87 88 90 91 92 93 94 95 96 97 98 7 A8 CF 1 Line Display Addresses Es Ss LEE ER ET __ o IS E rr 1 RES 80 87 88 90 91 92 93 94 95 96 97 98 A7 co c7 8 CF Do Di 02 23104 05 06 D7 D8 E7 2 Line Display Addresses eS 22 SE 2x20 E _________2220 e EEE ate d 81 88 89 90 91 92 93 94 95 96 97 98 99 80 C1 9 00 D1 02 03 04 05 06 D7 Ds 09 CO 2 Line Display Addresses with Display Shifted Left 0 1 5 1 See Entry Mode Set Instruction 2 5 Specially Coded Displays Three types of displays have different addressing than typical 1 or 2 line displays They are e 1 chip 1 line by 16 character displays e 4 line by 16 or 20 character displays e 4 line by 40 character displays 1 chip 1x16 The HD44780 has the ability to control up to 16 characters without any other driver ICs A lower cost 1 line by 16 character display can be manufactured to take advantage of this feature To do this it i2. 951 shoy peeu en SJOJOBIEYO 19 9 18eu geq 35 User s Manual Version 1 1 November 1 1999
3. 6 SAPIC E Small Alphanumeric LCD Controller 1 3 Viewing modes The fluid type polarizers and module construction determine the viewing mode and colour of the display Displays are either postive image dark characters on a light background or negative image light characters on a dark background Backlight capability is determined by the presence absence of a reflector or transflecter on the back side of the glass Reflective displays have a full reflector The cannot be backlit They offer the lowest power option and the best contrast in high ambient light conditions They are not available in positive image Transmissive displays are usually negative image and are backlit for best readability They can be used in well lit indoor conditions to dark environments typically not recommeded for daylight usage They offer a different appearance than typical LCDs bringing a light emitting look to the product Transflective displays combine the features of reflective and transmissive modes These positive image displays can be read in all lighting conditions The backlight can be turned on for low light levels or operated continuously to add the light emitting look to a product rrrr Positive Image Negative Image Colors TN positive image displays will have a silver grey background and dark almost black characters In the negative image the background will be black and the characters will be the color of the backlight u
4. 02 03 04 05 06 07 E5 E6 E7 4 Line by 40 Character Addresses 4x16 20 Because of the way the controller and drivers are connected to make maximum use of their outputs special attention must be paid to the addresses of these displays Logically line 3 follows line 1 and line 4 follows line 2 When the cursor gets to the end of line 1 it will jump to line 3 Keeping track of cursor location for proper positioning is important 80 81 82 83 84 85 86 87 88 89 BA 8B 8 80 BE eF 90 91 92 93 94 95 96 97 98 99 9B 9C 9D 9E OF Do D1 D2 D3 04 05 De 07 08 09 DA DB DC DD DE DF 4 Line by 16 Character Addresses 80 81 82 83 84 85 86 87 88 89 8A 8B 8C 8D 8E 90 91 92 93 CO 1 2 4 5 C6 7 C8 C9 DO D1 D2 03 94 95 96 97 98 99 9B 9C 90 9 9F AO 1 A2 A4 AS A7 05 06 07 08 09 DA DB DE DF E1 2 E3 E4 E5 E6 E7 4 Line by 20 Character Addresses 14 SAPIC E Small Alphanumeric LCD Controller 2 6 Instruction Table 3 Clears Display and returns EAD cursor to the Home Position Address 00 Returns cursor to Return Position Returns shifted 40us Home display to o
5. 4x4 keys e Serial quasi RS 232 interface e Jumper selectable baud rates 2400 9600 e No external power supply is required e Demo mode 3 2 Demo mode SAPIC E works in demo mode it the baud rate jumper is left unconnected In this mode the keypresses a 3x4 key telephone keypeds are echoed 2x16 LCD 3 3 Connectors 3 3 1 LCD SAPIC E can drive one or two one controller or one two controller LCDs Some LCD has the same pinout as the SAPIC E card others have different SAPIC E drives the LCD in 4 bit mode so there is no need to connect DO D3 lines RS S R W fe Ei 7 NG 00 01 9 NO 02 to 08 13 14 07 User s Manual Version 1 1 November 1 1999 23 3 3 2 Backlight SAPIC E can directly drive a LED backlight or supply power for external inverter for CFL backligh The LED backlight shall be connected to the backlight connector observing polarity By default two 100 ohm resistor are installed in parallel After shorting the current limiting resistors an inverter for CFL backlight can be connected to the backlight connector 3 3 3 Contrast Most LCD requires a voltage between 0 and 5V Others require voltage to be between 5V and 5V SAPIC E supports only the former The best value depends on the LCD type and the temperature therefore adjustments are often needed There are four ways of controlling the contrast e Using the internal trimmer It is the most co
6. If you reload a CG location which is currently on the display the change will be immediately apparent Displays employing multiple controllers ie 4 x 40 2 x 80 4 x 80 may create 8 symbols per controller The CG RAM adds interest and flexibility to the LCD module 20 SAPIC E Small Alphanumeric LCD Controller CG RAM DD RAM and pattern examples for 5x7 dot patterns Character Codes RAM Address Character Patterns DD RAM Data CG RAM Data 76543210 543210 10001 Character 11110 Pattern 10100 Example 1 1 11111 Character 00100 Pattern 11111 Example 2 00000 Cursor position Don t Care Notes a b 2 Character code bits 0 2 correspond to CG RAM address bits 3 5 for a total of 8 patterns CG RAM address codes 0 2 designate character pattern line The 8th line is the cursor position is logically OR ed with the cursor instruction Character patterns are loaded into CG RAM data bits 0 4 as shown in the table Bit 4 is the left side Since CG RAM bits 5 7 are not used they may be used for general data RAM CG RAM patterns are displayed on the LCD when character code bits 4 7 are all 0 Bit 3 is don t care bit Therefore character pattern 1 can be selected with character code 00H or 08H 1 in the character pattern turn a dot ON 0 indicates a non selected dot User s Manual Version 1 1 November 1 1999 21 CG RAM DD RAM and pattern examples for 5 10
7. Many TN and NTN models are available in extended temperature range Contact Densitron for current availability User s Manual Version 1 1 November 1 1999 5 1 2 1 Fluid TN Fluid is the least expensive type The viewing angle is about 40 45 and must be designated top or bottom view preference Bottom view is used when the user will be below the plane perpendicular to the display such as on a desk calculator Top view is used when the display is mounted on a vertical surface below eye level See diagram below a _ tip View CO jMyprewunate Nominal _ Viewing Cine Ea We Approx imate 7 View sw Cane _ GU mE View TN Viewing Cone 1 2 2 STN AND NTN Fluid STN and NTN are both high contrast and wide viewing angle fluids They differ in the level of contrast and viewing angle they achieve Both can be seen above and below the plane perpendicular to the display See the diagram below jusable Rupe Approximate binge Approximate Viewing Cone STN Viewing Cone The vertical viewing cone on all fluids can be adjusted by controlling the VO voltage The range of adjustment is shown in the viewing angle charts below The encon cone is relatively
8. 67H for the second line Because the MSB is set to 1 the hex codes are actually 80H to COH to A7H and to E7H respectively See Display Addressing for more information 18 SAPIC E Small Alphanumeric LCD Controller 2 7 9 Read and Address RS RW 07 D6 D5 D4 D3 D2 D1 DO _ 1 When 1 the system is internally operating on a previously received instruction The next instruction will not be received until BF 0 The value of the address counter also to read during this operation and is given in binary AAAAAAA Whether CG or DD RAM address is read is determined by the previous instruction 2 7 10 Write Data to CG RAM or DD RAM RS RW D7 06 D5 D4 D3 02 01 DO RARE Writes binary 8 bit data DDDDDDD to CG or the DD RAM Whether the CG or the DD is to be written is determined by the previous designation CG RAM address setting or DD RAM address setting After write the address is automatically incremented or decremented by one according to entry mode Display shift also follows the entry mode 2 7 11 Read Data from CG RAM or DD RAM RS D7 06 05 04 D1 00 3 Jr Epp DD Reads binary 8 bit data DDDDDDD from the CG or the DD RAM Whether the CG RAM or the DD RAM is to be read is determied by the previous designation Prior to inputting this read instruct
9. RL 0 Shift to the Left DL 0 4 bits 0 1 Line 0 5x7 Dot Font D 0 Display OFF C 0 Cursor OFF B 0 Blink OFF BF 0 Can accept instruction Execution Time changes when Frequency changes per the following example If Fcp or fose is 27 KHz 40uS x 250 270 37uS N F Don t Care 2 7 LCD Instruction Description 2 7 1 Clear Display RS RW D7 06 05 D4 D3 D2 D1 DO 0 0 0 0 0 0 0 0 0 1 Writes space code 20H into all the DD RAM addresses The cursor returns to Address 0 ADD 80H and display if it has been shifted returns to the original position In other words display disappears and the cursor goes to the left edge of the display the first line if a 2 or 4 line display module is used 2 7 2 Return Home RS RW 07 D6 05 D4 D3 D2 D1 00 0 0 0 0 0 0 0 0 1 Don t Care Returns the cursor to Address 0 ADD 80H and display if it has been shifted to the original position The DD RAM contents remain unchanged 16 SAPIC E Small Alphanumeric LCD Controller 2 7 3 Entry Mode Set RS RW 07 D6 05 D4 D3 D2 D1 DO ID Increments ID 1 or decrements ID 0 the DD RAM address by when writing or reading a character code DD RAM The cursor moves to the right when incremented by one The same applies to writing and reading CG RAM S Shifts the entire display to either the right or the left when S is 1 to th
10. Select LCD command register Use E1 0 0 Use E1 in the following instructions UseE2 0 oj0o 11 1 01 1 0 Use E2 in the following instructions Read LCD 0 1 Read LCD Read Keyboard 1 1 1 Readkeyboard code 4 1 2 Select Data D7 06 D5 D4 D3 D2 D1 DO 010 0 10 01 Select LCD data registers RS 1 Subsequent commands will be send to the LCD with RS 1 therefore the LCD will interpret them as data 4 1 3 Select Command D7 06 05 D4 D3 D2 D1 DO ERRAR Select LCD command registers RS 0 Subsequent commands will be sent to the LCD with RS 1 therefore the LCD will interpret them as data D7 06 05 D4 D3 D2 D1 DO papo Use for the following operations Subsequent commands will be sent to the first LCD controller You can use 1BH code too for compatibility with earlier versions of SAPIC 4 1 4 Use 1 User s Manual Version 1 1 November 1 1999 29 4 1 5 Use 2 D7 05 D2 Do Use 2 for the following oparations Subsequent commands will be sent to the first LCD controller Used only if either a two controller LCD or if two one controller LCD is connected to SAPIC E 4 1 6 Read LCD D7 05 04 02 bo po pegas R
11. SAPIC E Small LCD Controller User s Manual DENSITRON INTERNATIONAL PLC O DENSITRON LTD 1999 Unit 4 Airport Trading Estate Biggin Hill Kent 16 3BW U K Tel 44 1 959 700 100 Fax 44 1 959 700 300 Contents asia naan aan ohn a 3 1 Selecting an LCD module ceres 5 Tes LO O BICO E i E eure Eee Kk kW Rea ok o ka o Ee o E rd 5 VDO od eco a E E M A A AE 5 TN coc eee Foret EP ER ERE TS SD ER TEE CHER EI 6 1 2 2 SIN AND En DR 6 1 3 Viewing MOJES ree antt e ton bue su 7 1 4 Backlightighting character 7 To T EE coti aede RR RR cies 8 1 4 2 si cte oe Doe nece Co oe ode 8 Mere 9 1 5 1 Direct 9 1 5 2 SAPIC E Interface ara nas un n nda 10 1 6 MOUNTING SUGGES TON mi 10 2 LCD SONWarG os rp d eod cei d ood exi da cd a c Sa Dd ER a 11 11 2 8 A AR RA RR SR RR RE 11 2 3 ADI go sismo need anne enc bonus 12 2 4 Display AdOLESSINO ss aaa ande theod et EM d ae 12 2 5 Specially Coded Displays n roa 13 2 6 I
12. SAPIC E via standard serial line in either RS 232 or TTL level These commands control the operation of the LCD the backlight the software controlled contrast and the keyboard Interfacing the module to an existing micro system involves is quite straightforward Just connectit to a standard free serial line 1 6 Mounting Suggestion Care must be taken when mounting an LCD module to ensure that module is not stressed when installed and the surface is not exposed to scratches or harmful material Causing any kind of warp on the PCB of the module may product open columns or rows of dots or intermittent display Presure on the bezel from the top or against the bezel tabs will lead to similar problems The front surface of the module is a sensitive plastic polarizer not glass Liquid must not be allowed to condense upon the device Whenever possible install an optically correct protection Barrier between the outside world and the display This should be non polarized plastic or polycarbonate which will reduce the incidence of foreign object invasion and static discharge into the display To keep glare at a minimum mount the protective piece as close to the display surface as possible while preventing pressure on the piece from being transmitted to the LCD Non glare properties can be added to the protective piece at a slight loss of display Clarity Enclosure Paste gt P c LOB Module Mounting Suggestion 10 SAPIC E Sma
13. VO and set it correctly 5 Instruction Summary The following tables show both the LCD and the SAPIC E commands User s Manual Version 1 1 November 1 1999 33 80 2 9 2 19598 10510 50 2 9 Poa 90 seul 105112 80 2 9 2 2 19598 50 2 9 soul Z 5 z 14u uius 80 2 9 2 2 19598 50 2 9 seul z 23 951 80 2 9 5 2 2 Xg s ul z seulz MUS 1461 1081 0 ys ONY 50 1 9 1461105 eui 19S9H 119 50 SIOD Poa Ha 19598 5 ny 19 105 JOSIND 1 2 50 Ha 1051109 2 9 sum 19 9SN po 2 9 2XG 9598 ssoippe SSeJppe 50 Wa da 50 2xG 1055 SAPIC E Small Alphanumeric LCD Controller 34
14. ate the 8th custom character The locations 40 7F are the CG Programming locations only Once programmed these special characters are displayed by writing to character font locations 00 07 hex 00 will retun that character residing in locations 40 47 01 returns 48 4F etc See Font Chart While the CG RAM byte is 8 bits wide only the 5 least significant bits appear on the LCD Thus D4 represents the left most dot and DO the right most dot To illustrate loading a CG RAM byte with 1F turns all dots in that row on loading a byte with 00 turns all dots off All 7 or 8 rows must be programmed at each desired CG location Programming procedure is a with RS20 enter the address of the top row of the character to be programmed i e 40 48 50 etc b with RS 1 enter pattern data for row 1 top row C continue to enter pattern data for rows 2 8 it is not necesary to enter additional addresses if the module has been initialized with command 06 auto increment of cursor This procedure may be continued until all CG bytes have been loaded The CG RAM can create an attractive reverse video 3 x 5 pattern Numerals look especially good in this format Most letters can be executed The limitation of 8 characters can be circumvented by creating a library of custom symbols each totalling 8 resident in the host system Eight custom symbols can be displayed at any ONE time The CG RAM can be periodically reloaded as display requirements change
15. dad dd c dr 27 User s Manual Version 1 1 November 1 1999 3 3 5 Board Outline rara rara 28 4 SAPIC E SoflWare eicere rni etna cac aanraai daa aaea aiiai 29 4 1 SN PIC ECOMMANOS cy seas 29 4 1 1 Instruction QD E state ale eect ad e 29 4 1 2 Select opea E 29 4 1 3 Select i EE ER DP Eee 29 LN WE MEC 29 1 5 c a mat ML ES 30 7L 1 6 Hoad EOD niea o detained xe OR ERE 30 41 7 Read euren oet Grm EN UR OE 30 4 1 8 Resolving command 31 4 2 Programming 32 4 3 Toublesho otlbQg iere RD RR ptr RR 33 5 Instruction acci rune ewe eX rd rod assis sniasniansidanioo 33 4 SAPIC E Small Alphanumeric LCD Controller 1 Selecting an LCD module 1 1 Introduction Selecting an LCD module involves 3 basic design decisions 1 What size and format is required to display the desired information 2 What optical characteristics will look best in the package and attract the user to the product 3 What interface is most practical and what additional benefits it has Densitron produces dot matrix LCDs in two formats fully functional Alphanumeric Modules and fully populated Graphic modules This application note is for use with the alphanumeric A N or character type modules Alphanumeric mo
16. de is sent one nibble at a time with the most significant nibble sent first The function set in the initialization routine must change to accommodate this mode A recommended initialization routine is as follows 2 line display with 5x7 font 02H 08H 02H 08H 00H 06H 00H 01H If SAPIC E interface is used the LCD module is always programmed to 4 bit operation 2 4 Display Addressing The display RAM is 8 characters If the display is less than 80 characters what is on the screen is a window on the RAM What is displayed depends on the Entry Mode Set instruction Address diagrams on the next page show RAM addresses as they appear after a Clear Display or Return Home instruction or when Entry Mode Set instruction S 0 If a 2 line display has less than 40 characters per line the cursor will advance off the screen after the last character of the first line To put data on the secone line a Set DD RAM Address instruction must be sent When instruction S 1 the display is shifted This makes the characters look as though they are marching across the screen on entry It also lets small displays 2x16s for example to have data stored in non visible areas of the 12 SAPIC E Small Alphanumeric LCD Controller RAM and shifted in to view with one command The last diagram shows how the addresses wrap in this mode E 1858 5 L 1 24 _ me DER ERE LOERI ERIT ERG E
17. dot patterns Character Codes Character Patterns DD RAM Data 29 RAM Address GG Data 76543210 543210 43210 00000 00000 10110 1001 Character 0001 Pattern 0001 Example 1 1 1 1 1 1 1 1 00000 Cursor Position Don t Care Notes a b L 22 Character code bits 1 amp 2 correspond to CG RAM address bits 4 amp 5 for a total of 4 patterns CG RAM address codes 0 3 designate character pattern line The 11th line is the cursor position It is logically OR d with the cursor instruction Since lines 12 16 are not used for the display they may be used as general data RAM Character patterns are loaded into CG RAM data bits 0 4 as shown in the table Bit 4 is the left side Since CG RAM bits 5 7 are not used they may be used for general data RAM CG RAM patterns are displayed on the LCD when character code bits 4 7 are all 0 Bits 0 amp 3 are a don t care bits Therefore character pattern 1 can be selected with character code 00H 01H 08H 09H 1 in the character pattern turn a dot ON 0 indicates a non selected dot SAPIC E Small Alphanumeric LCD Controller 3 SAPIC E hardware 3 1 Introduction SAPIC E can interface most small alphanumeric LCDs that uses the Hitachi HD44780 chip to PC or other type of computer It has the following features e Software compatible with other SA cards e Support for 1 or 2 controller LCDs e Small keyboard interface max
18. dules display characters numerals symbols and some limited graphics Normally interface is achieved a bi directional parallel ASCII data bus A more advanced interface is achieved via SAPIC E card that controls backlight keyboard and up to two A N LCDs via serial line Necessary features such as Character Generation Display RAM Addressing Cursor Scrolling Blanking and Handshake are all included User programmable fonts are supported In summary these modules are the simplest and most economic means to communicate meaningfully between any micro system and the outside world Their inclusion adds to any product s appeal Alpha numeric modules range from 8 to 80 characters per line One two or four character lines may be chosen Character height spans 0 130 3 31 mm to 0 500 12 71 mm Most formats are available in a variety of packages to meet various mounting requirements Multi line models offer the best value when analyzed by a cost per character basis Displays are readable both day and night by selecting a backlight option Extended temperature modules are available which operate between 20 and 70C The following sections explains the optical characteristic options available in A N modules 1 2 Fluid types The fluid type determines the contrast ratio viewing angle and temperature range of an LCD Densitron uses 3 basic classes of fluid TN Standard type NTN high contrast type and STN premium high contrast type
19. e left when 10 1 and to the right when ID 0 Therefore the cursor looks as if stood stil while only the display has moved Display is not shifted when reading from DD RAM Display is not shifted when S 0 2 7 4 Display On Off Control RS RW 07 D6 D5 D4 D3 D2 D1 DO D Display is turned ON when D 1 and OFF when D 0 When display is turned off due to D 0 the display data remains in the DD RAM and it can be displayed immediately by setting D 1 C The cursor is displayed when C 1 and not displayed when C 0 Even if the cursor disappears function of I D etc does not change during display data write The cursor is displayed using 5 dots in the 8th lines when the 5 x 7 dot character font is selected and in the 11th line when 5 x 10 dot character font is selected B The character residing at the cursor position blinks when B 1 The blink is done by switching between all dots ON and display characters at 0 4 second interval The cursor and the blink can be set concurrently G GAO Detached Attached Blinking Character Cursor Position 2 44 User s Manual Version 1 1 November 1 1999 17 2 7 5 Cursor or Display Shift RS 07 06 05 4 D1 00 1 5 Don t Care Shifts the cursor position or display to the right or left without writing or reading the display data This function is used for correction or search of disp
20. e remaining voltage at the desired current For example if 200mA produces the desired brightness and the supply voltage is 5VDC the limit resistor will drop 0 8VDC 5 0 4 2 Therefore R 0 8 0 2 4ohms 1 5 Interface Two interface methods can be usd to connect LCD to host system In direct connection the host system is responsible for creating all the signals for the LCD This requires good understanding of the LCD Connection via SAPIC E interface card is much simpler it is done via serial line Commands sent to the SAPIC E are transferred to the LCD or interpreted by the controller 1 5 1 Direct Interface A N modules are an intelligent peripheral which can communicate bi directionally within the master system Tie the device into the system data bus and treat it as RAM I O or expanded parallel I O The module is selected by gating a decoded module address output with the host processor s read or write strobe The resultant signal applied to the LCDs enable input clocks in data There is no conventional chip select Interfacing the module to an existing micro system involves joining the module to the host s data bus b developing a strobe signal for the E signal applying appropriate signals to modules RS and R W d applying the proper viewing angle voltage to the display s VO pin User s Manual Version 1 1 November 1 1999 9 1 5 2 SAPIC E Interface Commands are sent to the
21. ead the busy or the data register of the LCD depending on RS Reading the busy flag will always return not busy because the speed of the serial line is less than the LCD 4 1 7 Read Keyboard D7 06 05 D4 D3 D2 D1 DO 0 0 0 1 1 0 0 1 Check the keyboard Return the keycode or if no key is pressed then return OFFH The keycodes are lised in the following table The SAPIC E software debounces the key but additional debouncing may also be required especially for larger matrices in noisy environment 4 1 7 1 Special Codes As the SAPIC E can access the LCD in 4 bit wide interface modes commands that changes to 8 bit wide interface has no effect SAPIC E automatically convert these commands to their 4 bit equivalent In data mode the code OFH is replaced with OOH This is for the convenience of users who are unable to send the 00H code 30 SAPIC E Small Alphanumeric LCD Controller 4 1 8 Resolving command conflict Most of the codes that are received by the SAPIC E card are sent to the LCD However the special codes that control the SAPIC E card are interpreted first Sometimes the user want to send these codes to the LCD Depending on the operating mode it is possible to send other codes to the LCD to have the same effect The LCD has three operating mode Command mode e n data mode writing the data memory n data mode writing the character generator memory The following table list alternate code
22. ent e DD RAM is selected The display will be busy for approximately 15mS after power ON JS OFF gt sins Power Supply Timing Requirements for Internal Initialization User s Manual Version 1 1 November 1 1999 11 If power supply rise time cannot be assured of meeting the requirements above or if different parameters are required such as for a 2 line display an initialization routine will have to be sent from the host When first setting up the display Densitron recommends the following initialization routines for 8 bit interfaces e 1 line display with 5x7 font e 06H OEH 01H e 1 line display with 5x10 font 34H 34H 06H OEH 01H e 2 line display with 5x7 font e 38H 38H 06H 01H Wait states should be programmed to allow 15mS after power up before initialization begins Waiting 4 1mS between the 3X codes and 1005 after the second 3X code add a safety margin and ensure proper initialization After sending this routine you should have a clear display with a flashing cursor in the upper left position The cursor will then increment to the right with each data RAM write command If you do not have this display see Troubleshooting Tips in the appendix 2 3 4 bit Operation The modules will operate a 4 bit wide data bus Data is transferred over data lines D7 D4 D3 DO may float 8 bit hex co
23. ion either the CG RAM address set instruction or the DD RAM address set instruction must be executed If it is not done the first read data becomes invalid and data of the next address is read normally from the second read After read the address is automatically incremented or decremented by one according to the entry mode However display shift is not performed regardless of entry mode types User s Manual Version 1 1 November 1 1999 19 2 7 12 The Use of CG RAM Character Generator CG RAM is a useful accessory It does not have to be used or attended to during any normal display operation CG RAM allows the creation of up to 8 special character or symbols Once programmed the newly formed characters may be accessed as if they were in the normal CG ROM This ROM contains 192 unchangeable characters Thus the CG RAM expands the character representation available to the user NOTE This is a RAM and must be reprogrammed if display power is interrupted If used regularly programming can be made part of the initialization routine There are two distinct areas of RAM within the display module The main area 80 bytes wide is dedicated to the display and is called Display Data DD RAM CG RAM consists of 64 bytes which range from 40 to 7F hex or 4 5x10 or 5x11 symbols 40 47 locate the first custom 5x7 character 40 is the top row of this character 47 is the 8th row Similarly 48 4F locate the second CG character and 78 7F loc
24. lay Shifts the cursor position to the left AC is decremented by one 0 1 Shifts the cursor position to the right AC is incremented by one 1 O Shifts the entire display to the left The cursor follows the display shift Shifts the entire display to the right The cursor follows the display shift 2 7 6 Function Set RS RW D7 D6 D5 D4 D3 D2 01 DO Eo oed proe e pne JEN LUE eo Don t Care DL Sets interface data length Data is sent or received in 8 bit length DB7 DBO when DL 1 and 4 bit length DB7 DB4 when DL 0 When 4 bit length is selected data must be sent or received in 2 operations N Sets number of display lines F Sets character font Together N amp F set the duty cycle 2 7 7 Set CG RAM Address 0101 Sets the CG RAM address in a binary number of to address counter and data is written or read from the MPU related to the CG RAM after this This is used for programming the Character Generator CG RAM 2 7 8 Set DD RAM Address RS 07 D6 05 D4 D3 D2 D1 00 O 710 4 3 Sets the DD RAM address in a binary number of AAAAAAA in the address counter Data is written or read from the MPU related to the DD RAM after this When 0 1 line display AAAAAAA is to 47H When 1 2 line display AAAAAAA for the first line is to 27H and 40H to
25. lit module Standard color is yellow green Red amber and other colors may be specially ordered 8 SAPIC E Small Alphanumeric LCD Controller Edgelit Style Array Style LED Backlight Functional Diagram Densitron offers two types of LED backlights edgelit and array Their basic format is shown above Edgelit can be used on modules up to 20 characters wide Beyond 20 characters the middle of the display begins to dim when compared to the edges The LM43X series uses a top mounted edgelight to achieve its balance of light and power Edgelight is the lower power of the two types The 4XXX series edgelit modules typically operate 30 to 60mA at 5VDC and come with a built in current limit resistor The 43X series is somewhat higher and must have a limited resistor in series for proper operation Array backlighting produces a brighter and more even light Power is the main consideration when designing with this type of module It is not recommended for battery powered applications where the lamp will be on all the time It may be suitable for on demand applications Limit resistors must be used for array backlit modules and the LM43X series Refer to the specific module specification for recommended and or maximum backlight ratings LEDs are arranged in serial pairs and operated in parallel see diagram The lamp will require 4 2VDC Brightness can be set or controlled by selecting the proper limit resistor Select a resistor that will drop th
26. ll Alphanumeric LCD Controller 2 LCD software 2 1 Introduction Software determines what how and where data is displayed on the LCD All Densitron character modules feature the Hitachi HD44780 or equivalent controller IC This versatile chip features e Built in character generator with 192 character modified ASCII character set e Ability to program up to 8 custom characters e Bi directional 8 or 4 bit bus interface e 80 character RAM e Automatic reset on power up e Wide range of instruction functions including Display clear Cursor positioning Display or cursor shift on data entry and Display ON OFF If the LCD is connected to the host system via SAPIC E card additional commands are available to control the backlight the software contrast and the keyboard LCD instructions are explained in detail on the following pages and the special SAPIC E commands are explained in SAPIC E software section 2 2 Initialization The module has 2 registers one for inputting instructions and one for reading or writing data Instructions are used to tell the module how and where to put the data If the rise time of the power supply meets the criteria below the module will default to the following functions an internal initialization routine e Clear Display e Function Set DL 1 8 bits interface N 0 1 line display F 0 5x7 dot font e Dislay ON OFF control D 0 Display OFF C 0 Cursor OFF B 0 Blink OFF e Entry Mode Set 1 1 increm
27. mmon way of setting the optimal contrast e Using an external potmeter connected to the contrast connector Changing the contrast by external potmeter is convenient when the card operates at widely varying temperature e Setting a fixed value In cost sensitive applications two SMD resistor can be installed instead of the trimmer 3 3 4 Power SAPIC E can generate its power from the DTR line if backlight is not used or 5V 20 power can be supplied on either of the connector SAPIC E is a low power device Without LCD it consumes less than 1mA typical 24 SAPIC E Small Alphanumeric LCD Controller 3 3 5 Serial Line Either RS 232 or inverted TTL serial signals can be used The RS 232 or the inverted TTL signals should be connected to RXD and TXD pins The DTR and RTS signals can be used to supply power to SAPIC E and the LCD The DTR and RTS signals when high can supply power for the SAPIC E card and the LCD but not for the backlight Sometimes additional 5V power is required for the LCD Standard RS 232 cable connection between PC and SAPIC E The baud rate is jumper selectable by a small jumper at the solder side of the card The format is always 8 data bits 1 stop bit no parity 2400 side connected 9600 baud 9600 side connected 4800 baud The RS 232 interface is not fully RS 232 compatible it cannot drive long cables User s Manual Version 1 1 November 1 1999 25 3 3 6 Keyboard SAPIC E directly
28. mp brightness and life are inversely proportional That is the harder the lamp is driven the brighter it will be but the shorter the life Under rated operating conditions lamp life is about 2 000 to 2 500 hours to half its original brightness Operating conditions such as temperature and humidity will also effect lamp life The graph below illustrates the brightness vs life curve of INITIAL BRIGHTNESS KA D 1000 TYPICAL EL LAMP Recommended inverters for various sizes of modules are shown below Design considerations such as the operating conditions desired brightness required light and lamp life must be balanced when designing with EL backlighting For example a negative transmissive display used in normal room lighting may look better when driven with a larger inverter but useful life will be shortened Displays DAS5V4 All A N Displays except 4x40 2x40 LM300 amp LM4700 Series DAS5V7 4x40 2x40 LM300 amp LM700 Series Transflective DAS5V8 4x40 2x40 LM300 amp LM700 Series Transflective Inverter Recommendations 1 4 2 LED Backlighting LED backlighting offers a significant life advantage over EL lamps but at the sacrifice of power and module size Lamp life is in excess of 50 000 hours and in most cases 1 lamp failing does not make the backlight unusable LED backlit does not make the backlight unusable LED backlit modules are 2 4mm thicker than an EL or non back
29. nstruction SABE e bea wo er sorte 15 2 7 LCD Instruction DesceripliOn erre rete 16 2 73 leah DISDIB scie nen sor qan Donc Sn n Du a 16 2 7 2 Return HOME ens ROC 16 2 7 3 Entry Mode DOU uua deed 17 2 7 4 Display On Off Control 17 2 7 5 Cursor or Display matasse aera 18 NA EE 18 2 57 oet GG RAM AOS GS iiu aerea ios e peu nets 18 2 7 8 Set DD RAM ACROSS ec reet 18 2 7 9 Read Busy Flag and 19 2 7 10 Write Data to CG RAM or DD 19 2 7 11 Read Data from CG RAM or DD 19 2 7 12 The Use of CG RAM aaa 20 3 SAPIC E 23 8 1 er Our 23 3 2 Demo mide suce cocto etc eoe roc eoe etc eo eoe eoe etate etg 23 3 9 ONMECIONS aera ecce v oce voee vp vo ovv voee vp vo eo v 23 E 23 25222 Baek 6 soceri ER Sp 24 229 2 24 2 94 POWER PLC Lc 24 Bie Os SOTA LNG e nr ar ia fa aaa aaa 25 9 36 DR eb tate Aes aus 26 9 4 star
30. riginal position 1 6ms Does not clear displa Sets DD RAM counter to Entry increment or decrement Mode Set 1 5 ID Specifies cursor or 40us display shift during to Data Read or Write S Display Sets MON ES CE o m blink character at cursor SOS position Cursor or Moves cursor or shifts the Display display w o changing DD 40us RAM contents Shift character font F Sets CG RAM address CG RAM data is sent and received after this 4005 instruction Sets DD RAM address DD RAM data is sent and received after this 4005 instruction bon 2 Reads Flag BF 16 address counter contents Writes data to DD or CG 2 Data coe e counter AC Reads data from DD or CG Read Data RAM and increments or from RAM 1 Read Data decrements address 40uS counter AC Function Sets data bus length DL of display lines N and 40us User s Manual Version 1 1 November 1 1999 15 01 Increment S 1 Display Shift data entry SC 1 Display Shift RAM unchanged RL 1 Shift to the Right DL 1 8 bits N 1 2 Lines F 1 5x10 Dot Font D 1 Display ON C 1 Cursor ON B 1 Blink ON BF 1 Cannot accept instruction Definitions DD RAM Display data RAM CG RAM Character generator RAM Aca CG RAM Address App DD RAM Address Cursor Address AC Address Counter used for both DD and CG RAM Address 10 0 Decrements S 0 Cursor Shift on data entry SC 0 Cursor Shift RAM unchanged
31. s necessary to initialize the display in the 2 line mode The display is then addressed as a 2 line display Line 1 addresses the first 8 characters line 2 the second 8 When the cursor gets to the ninth character of the first line it will disappear into undisplayed RAM assuming no display shift A Set DD User s Manual Version 1 1 November 1 1999 13 RAM Address must be sent to reposition the cursor to the ninth displayed character which is logically the first position of the second line 80 81 82 83 84 85 86 87 1 2 4 5 6 7 1 Chip 1 Line by 16 Character Addresses 4x40 The maximum capacity of the HD44780 is 80 characters The 160 characters on the 4x40 displays are accessed with 2 controllers The first controller handles the top two lines the second controller is conected to the bottom two lines They share all I O lines except the E Logically the display is like two displays connected to the MPU as the lines must independent Remember to turn off the cursor when moving from one half of the display to the other to avoid viewer distraction E1 used 80 81 82 8F 90 91 92 93 94 95 96 97 A5 7 Et used Co C1 C2 CF Do D1 D2 D3 D4 D5 De D7 E5 Ee E7 E2 used 80 81 82 8F 90 91 92 93 94 95 96 97 A5 A6 A7 E2 used C1 C2 00 Di
32. s that has the same effect on the LCD Code SAPIC E command LCD command LCD data char gen OH User defined char 0 08H E 03H OA BA 12H Use E1 10H 10H 92H 19H 36H AH User s Manual Version 1 1 November 1 1999 31 4 2 Programming Example Assuming that a 16x2 LCD is connected to the SAPIC E the following code sequence will write the text DENSITRON to the first line of the LCD You can send the codes to the SAPIC E by any terminal program OCH Display on no cursor 08H Datamode 4EH LeterN SSH Leterg AsH LeterT BMH LeterT n 32 SAPIC E Small Alphanumeric LCD Controller The following code sends this sequence to the LCD example c include lt stdio h gt include lt bios h gt Define serial port define PORT 1 COM2 Send this string to SA const char message x0A x12 x28 x01 x12 x0C x08 DENSITRON Example int main int argc char argv l int i Send data to serial line for 1 0 message i i 4 bioscom COM SEND message i PORT return 0 4 3 Toubleshooting When you first connect SAPIC E to the PC and the LCD fails to respond check the following 1 Using SPLITCOM or another terminal program send Use E1 12H commands to SAPIC E SAPIC E should echo the codes 2 Send Read keys 19H code SAPIC E should return 19H OFFH if no key 15 pressed 3 Measure
33. sually yellow green or white See section on backlighting NTN and STN positive image displays can have a silver or yellow background with dark characters Negative image versions have a dark blue background characters are the folour of the backlight Choice of color is determined by what fits best in the package Not all NTN displays are available in all colors Consult Densitron for current availability 1 4 Backlightighting character modules Backlighting is used on LCDs to make them readable in low light conditions Refer to the section on viewing modes for the types and applications of display that are backlit Densitron currently uses 2 methods to backlight character LCD module Electroluminescent EL and Light Emitting Diode LED Selection depends on desired color available power and required life User s Manual Version 1 1 November 1 1999 7 1 4 1 EL Backlighting EL backlighting is the original LCD backlight It is thin lightweight low power and fits between the glass assembly and PCB without any modification to the module Most positive mode displays are furnished with a blue green lamp Negative mode displays usually come with a white lamp Other colors can be specially ordered EL lamps operate from an AC power source typically 400Hz at 70 110 VAC Densitron supplies a full range of DC to AC inverters to power the lamps from a 5VDC source There is no hard and fast rule for matching an inverter to a specific lamp La
34. supports a 4x4 keyboard and via expansion registers a 60x4 keyboard The additinal key are connected via HC164 shift registers One HC164 shift register is required for each 8x4 keyfield Max 7 HC164 can be used The maximum number of keys are 240 Two connector type is used simple and extended The simple connector supports only the first 16 keys the extended one the first 48 keys Both connector type can be further extended by using additional shift registers Keyboard connector _ _ e ROWi 7 ROWw2 8 ROWS 26 SAPIC E Small Alphanumeric LCD Controller it diagram 3 4 6661 7 L0 1404 5 VS 19946 1910 08 ayes pneg 00 TA TH g 0096 974291014 27 User s Manual Version 1 1 November 1 1999 3 5 Board Outline SAPIC E is available in three versions e Card form e Evaluation version with 3x4 key keypad and 2x16 LCD e DIP chip version e SOIC chip version 28 SAPIC E Small Alphanumeric LCD Controller 4 SAPIC E software 4 1 SAPIC E Commands In addition to the LCD commands that are directly passed to the HD44780 LCD controller SAPIC E has an additional commands 4 1 1 Instruction Table Instruction _____ 07106 05 D4 03 D2 D1 DO Description Select Data 1 0 Select LCD data register Select Command 0 o o fo f4 o 1 0
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