TITLE "LCD direct driving" List P=16F913, R=DEC INCLUDE "p16F913.inc" SCL EQU 1 ; Clock line setup SDA EQU 0 ; Data line setup ; data segment in the shared area of all banks CBLOCK 0x70 tempC:2, tens, units, tempOld displayCodes:2, mode err_i2c, dataIO, ACK_NAK, cnt ; I2C interface vars ENDC PAGE __CONFIG _DEBUG_OFF & _FCMEN_OFF & _IESO_OFF & _BOD_OFF & _CPD_OFF & _CP_OFF & _MCLRE_OFF & _PWRTE_ON & _WDT_ON & _INTOSCIO org 0 btfss STATUS, NOT_TO ; WDT reset? goto loop ; YES - keep running goto main ; NO - start initialization ; the next fours procedures are for the LCD 7-segment encoding codeUr addwf PCL, f retlw b'00000111' ; right part of digit 0 retlw b'00000001' ; right part of digit 1 retlw b'00001110' ; right part of digit 2 retlw b'00001011' ; right part of digit 3 retlw b'00001001' ; right part of digit 4 retlw b'00001011' ; right part of digit 5 retlw b'00001111' ; right part of digit 6 retlw b'00000001' ; right part of digit 7 retlw b'00001111' ; right part of digit 8 retlw b'00001011' ; right part of digit 9 retlw b'00001101' ; right part of digit A retlw b'00001111' ; right part of digit B retlw b'00000111' ; right part of digit C retlw b'00001111' ; right part of digit D retlw b'00001110' ; right part of digit E retlw b'00001100' ; right part of digit F codeUl addwf PCL, f retlw b'01000011' ; left part of digit 0 retlw b'00000001' ; left part of digit 1 retlw b'00000011' ; left part of digit 2 retlw b'00000011' ; left part of digit 3 retlw b'01000001' ; left part of digit 4 retlw b'01000010' ; left part of digit 5 retlw b'01000010' ; left part of digit 6 retlw b'00000011' ; left part of digit 7 retlw b'01000011' ; left part of digit 8 retlw b'01000011' ; left part of digit 9 retlw b'01000011' ; right part of digit A retlw b'01000000' ; right part of digit B retlw b'01000010' ; right part of digit C retlw b'00000001' ; right part of digit D retlw b'01000010' ; right part of digit E retlw b'01000010' ; right part of digit F codeTr addwf PCL, f retlw b'11110000' ; right part of digit 0 retlw b'01000000' ; right part of digit 1 retlw b'11100000' ; right part of digit 2 retlw b'01100000' ; right part of digit 3 retlw b'01010000' ; right part of digit 4 retlw b'00110000' ; right part of digit 5 retlw b'10110000' ; right part of digit 6 retlw b'01100000' ; right part of digit 7 retlw b'11110000' ; right part of digit 8 retlw b'01110000' ; right part of digit 9 retlw b'11110000' ; right part of digit A retlw b'10010000' ; right part of digit B retlw b'10110000' ; right part of digit C retlw b'11000000' ; right part of digit D retlw b'10110000' ; right part of digit E retlw b'10110000' ; right part of digit F codeTl addwf PCL, f retlw b'00011000' ; left part of digit 0 retlw b'00001000' ; left part of digit 1 retlw b'10010000' ; left part of digit 2 retlw b'10011000' ; left part of digit 3 retlw b'10001000' ; left part of digit 4 retlw b'10011000' ; left part of digit 5 retlw b'10011000' ; left part of digit 6 retlw b'00001000' ; left part of digit 7 retlw b'10011000' ; left part of digit 8 retlw b'10011000' ; left part of digit 9 retlw b'10001000' ; right part of digit A retlw b'10011000' ; right part of digit B retlw b'00010000' ; right part of digit C retlw b'10011000' ; right part of digit D retlw b'10010000' ; right part of digit E retlw b'10000000' ; right part of digit F main bsf STATUS, RP0 ; change to BANK 1 movlw 7 movwf CMCON0 ; comparators off clrf ANSEL ^ 0x80 ; all inputs digital clrf OSCCON ^ 0x80 ; oscillator configuration bits ; LCD module configuration clrf TRISA ^ 0x80 ; STEP 1 clrf TRISB ^ 0x80 movlw b'00000100' movwf TRISC ^ 0x80 bcf STATUS, RP0 bsf STATUS, RP1 ; change to BANK 2 bsf LCDCON ^ 0x100, VLCDEN ; STEP 2: enable LCD bias voltage pins bsf LCDCON ^ 0x100, CS1 ; STEP 3: select clock source (lfintosc) bcf LCDCON ^ 0x100, CS0 bcf LCDCON ^ 0x100, LMUX1 ; STEP 4: select multiplex mode (static) bcf LCDCON ^ 0x100, LMUX0 bcf LCDPS, WFT ; STEP 5: select waveform type (A) bcf LCDPS, BIASMD ; STEP 6: select Bias mode bcf LCDPS, LP3 ; STEP 7: select refresh rate bcf LCDPS, LP2 bsf LCDPS, LP1 bcf LCDPS, LP0 movlw 0xFF ; step 8: enable LCD segment lines movwf LCDSE0 movlw b'11111011' movwf LCDSE1 clrf LCDDATA0 ^ 0x100 ; step 9: clear segment data registers clrf LCDDATA1 ^ 0x100 bsf LCDCON ^ 0x100, LCDEN ; step 10: turn on the LCD driver module bcf LCDCON ^ 0x100, SLPEN ; enable LCD in sleep mode movlw b'00001010' movwf WDTCON ; watchdog timer prescaler 1:1024 bcf STATUS, RP1 ; back to BANK 0 ; setup TCN75A temp resolution of 0.0625C and shutdown call start_I2C movlw b'10010000' ; address byte movwf dataIO call write_I2C ; send address byte movlw 1 movwf dataIO ; config pointer call write_I2C movlw b'01100001' movwf dataIO ; temp resolution call write_I2C call stop_I2C clrf tempOld clrf mode loop ; MAIN LOOP btfss mode, 0 goto getTemp clrwdt call getTemp1 ; mode 0: request new temp conversion incf mode, f sleep nop getTemp clrwdt call getTemp2 ; mode 1: get temp from sensor incf mode, f movf tempOld, w subwf tempC, w btfss STATUS, Z ; old temp = new one? call displayTemp ; NO - update display sleep nop goto loop displayTemp clrf displayCodes clrf displayCodes+1 movlw 150 subwf tempC, w btfsc STATUS, C bsf displayCodes+1, 5 ; display hundreds call temp2BCD movwf tens movwf units swapf tens, f movlw 0x0F andwf tens, f andwf units, f btfsc displayCodes+1, 5 goto dispTens ; display tens for temp >= 100F movf tens, w btfsc STATUS, Z ; do not display tens if it is 0 goto dispUnits ; and temp < 100 dispTens movf tens, w ; displaying tens call codeTr iorwf displayCodes, f movf tens, w call codeTl iorwf displayCodes+1, f dispUnits movf units, w ; displaying units call codeUr iorwf displayCodes, f movf units, w call codeUl iorwf displayCodes+1, f movf displayCodes+1, w ; update LCD movwf LCDDATA1 ^ 0x100 movf displayCodes, w movwf LCDDATA0 ^ 0x100 bcf STATUS, RP1 ; back to BANK 0 return start_I2C ; start setup for I2C interface movlw 0x87 ; setup FSR to point to TRISC movwf FSR movlw b'11111100' andwf PORTC, f bsf INDF, SDA ; pull high SDA and SCL bsf INDF, SCL goto $+1 ; delay slot bcf INDF, SDA ; set data low nop ; wait for slave to detect it bcf INDF, SCL ; set clock low return stop_I2C ; stop setup for I2C interface movlw b'11111100' andwf PORTC, f bcf INDF, SCL ; make sure that clock and data bcf INDF, SDA ; lines are low nop bsf INDF, SCL ; release clock line nop bsf INDF, SDA ; release data line return write_I2C ; write byte to I2C line movlw b'11111100' andwf PORTC, f bcf INDF, SCL ; make sure that clock is low clrf err_i2c ; start with no error movlw 8 movwf cnt ; bits counter w_loop bcf INDF, SDA ; start w. data bit low rlf dataIO, f ; get the rightmost data bit btfss STATUS, C bcf INDF, SDA ; now the data bit is on the line btfsc STATUS, C bsf INDF, SDA goto $+1 bsf INDF, SCL ; raise clock up nop bcf INDF, SCL ; ... and low decfsz cnt, f goto w_loop ; repeat this 8 times bsf INDF, SDA ; check ACK from slave goto $+1 ; let slave respond bsf INDF, SCL ; clock up btfsc PORTC, SDA ; check the ACK from slave incf err_i2c, f ; no ACK (error) bcf INDF, SCL ; clock down return read_I2C ; read byte from I2C line movlw b'11111100' andwf PORTC, f bcf INDF, SCL ; make sure that clock is low movlw 8 movwf cnt ; bits counter r_loop bcf INDF, SCL ; set clock low for long enough goto $+1 bsf INDF, SCL ; set clock high bcf STATUS, C btfsc PORTC, SDA bsf STATUS, C ; C = data bit rlf dataIO, f ; insert it into the data byte decfsz cnt, f goto r_loop ; repeat this 8 times bcf INDF, SCL ; sending the ACK/NAK to slave bsf INDF, SDA movf ACK_NAK, f ; the NAK signal btfsc STATUS, Z bcf INDF, SDA ; the ACK signal nop bsf INDF, SCL ; raise clock up nop bcf INDF, SCL ; ... and low nop bsf INDF, SDA ; release the data line return getTemp1 ; request TEMP conversion call start_I2C movlw b'10010000' ; address byte movwf dataIO call write_I2C ; send address byte movlw 1 movwf dataIO ; config pointer call write_I2C movlw b'11100001' ; request one-shot temp conv movwf dataIO ; temp resolution call write_I2C call stop_I2C return getTemp2 ; read TEMP from sensor call start_I2C movlw b'10010000' ; address byte/W movwf dataIO call write_I2C ; send address byte clrf dataIO ; TEMP register pointer call write_I2C call start_I2C movlw b'10010001' ; address byte/R movwf dataIO call write_I2C ; send address byte clrf ACK_NAK call read_I2C ; get TEMP high order byte movf dataIO, w movwf tempC incf ACK_NAK, f ; setup to send NAK signal call read_I2C ; get TEMP low order byte movf dataIO, w movwf tempC+1 call stop_I2C rlf tempC+1, f ; shift a bit from the low order byte rlf tempC, f ; into the high one btfsc STATUS, C ; negative temp ? goto negative rlf tempC+1, f rlf tempC, f ; too high hemp (> 63.75C) ? btfsc STATUS, C goto tooHot return negative clrf tempC ; ignore negative temp, show it as 0 return tooHot movlw 0xFF ; do not show temperatures higher movwf tempC ; than 63.75C return temp2BCD movf tempC, w movwf tempOld ; update old temp bsf STATUS, RP1 ; switch to BANK 2 movwf EEADRL ; set address (in Wreg) to read bsf STATUS, RP0 ; switch to BANK 3 bcf EECON1, EEPGD bsf EECON1, RD ; load byte form EEPROM bcf STATUS, RP0 ; back to BANK 2 movf EEDATL, w ; move it to Wreg return ORG 0x2100 ; Celcius to Fahrenheit conversion table dt 0x32, 0x32, 0x33, 0x33, 0x34, 0x34, 0x35, 0x35 dt 0x36, 0x36, 0x37, 0x37, 0x37, 0x38, 0x38, 0x39 dt 0x39, 0x40, 0x40, 0x41, 0x41, 0x41, 0x42, 0x42 dt 0x43, 0x43, 0x44, 0x44, 0x45, 0x45, 0x46, 0x46 dt 0x46, 0x47, 0x47, 0x48, 0x48, 0x49, 0x49, 0x50 dt 0x50, 0x50, 0x51, 0x51, 0x52, 0x52, 0x53, 0x53 dt 0x54, 0x54, 0x55, 0x55, 0x55, 0x56, 0x56, 0x57 dt 0x57, 0x58, 0x58, 0x59, 0x59, 0x59, 0x60, 0x60 dt 0x61, 0x61, 0x62, 0x62, 0x63, 0x63, 0x64, 0x64 dt 0x64, 0x65, 0x65, 0x66, 0x66, 0x67, 0x67, 0x68 dt 0x68, 0x68, 0x69, 0x69, 0x70, 0x70, 0x71, 0x71 dt 0x72, 0x72, 0x73, 0x73, 0x73, 0x74, 0x74, 0x75 dt 0x75, 0x76, 0x76, 0x77, 0x77, 0x77, 0x78, 0x78 dt 0x79, 0x79, 0x80, 0x80, 0x81, 0x81, 0x82, 0x82 dt 0x82, 0x83, 0x83, 0x84, 0x84, 0x85, 0x85, 0x86 dt 0x86, 0x86, 0x87, 0x87, 0x88, 0x88, 0x89, 0x89 dt 0x90, 0x90, 0x91, 0x91, 0x91, 0x92, 0x92, 0x93 dt 0x93, 0x94, 0x94, 0x95, 0x95, 0x95, 0x96, 0x96 dt 0x97, 0x97, 0x98, 0x98, 0x99, 0x99, 0x00, 0x00 dt 0x00, 0x01, 0x01, 0x02, 0x02, 0x03, 0x03, 0x04 dt 0x04, 0x04, 0x05, 0x05, 0x06, 0x06, 0x07, 0x07 dt 0x08, 0x08, 0x09, 0x09, 0x09, 0x10, 0x10, 0x11 dt 0x11, 0x12, 0x12, 0x13, 0x13, 0x13, 0x14, 0x14 dt 0x15, 0x15, 0x16, 0x16, 0x17, 0x17, 0x18, 0x18 dt 0x18, 0x19, 0x19, 0x20, 0x20, 0x21, 0x21, 0x22 dt 0x22, 0x22, 0x23, 0x23, 0x24, 0x24, 0x25, 0x25 dt 0x26, 0x26, 0x27, 0x27, 0x27, 0x28, 0x28, 0x29 dt 0x29, 0x30, 0x30, 0x31, 0x31, 0x31, 0x32, 0x32 dt 0x33, 0x33, 0x34, 0x34, 0x35, 0x35, 0x36, 0x36 dt 0x36, 0x37, 0x37, 0x38, 0x38, 0x39, 0x39, 0x40 dt 0x40, 0x40, 0x41, 0x41, 0x42, 0x42, 0x43, 0x43 dt 0x44, 0x44, 0x45, 0x45, 0x45, 0x46, 0x46, 0x47 end