TITLE "CO detector" List P=16F917, R=DEC INCLUDE "p16F917.inc" ; data segment in the shared area CBLOCK 0x70 del, delTMP, temp, buzzT coValue, coHigh hundreds, tens, units, displayCodes:3 ENDC PAGE __CONFIG _DEBUG_OFF & _FCMEN_OFF & _IESO_OFF & _BOD_OFF & _CPD_OFF & _CP_OFF & _MCLRE_OFF & _PWRTE_ON & _WDT_OFF & _INTOSCIO ORG 0 goto main codeUnitsR ; 7-segment encoding routines addwf PCL, f retlw b'10001110' ; right part of digit 0 retlw b'00001000' ; right part of digit 1 retlw b'10001101' ; right part of digit 2 retlw b'10001101' ; right part of digit 3 retlw b'00001011' ; right part of digit 4 retlw b'10000111' ; right part of digit 5 retlw b'10000111' ; right part of digit 6 retlw b'00001100' ; right part of digit 7 retlw b'10001111' ; right part of digit 8 retlw b'10001111' ; right part of digit 9 codeUnitsL addwf PCL, f retlw b'10010000' ; left part of digit 0 retlw b'00010000' ; left part of digit 1 retlw b'10000000' ; left part of digit 2 retlw b'00010000' ; left part of digit 3 retlw b'00010000' ; left part of digit 4 retlw b'00010000' ; left part of digit 5 retlw b'10010000' ; left part of digit 6 retlw b'00010000' ; left part of digit 7 retlw b'10010000' ; left part of digit 8 retlw b'00010000' ; left part of digit 9 codeTensR addwf PCL, f retlw b'00110000' ; right part of digit 0 retlw b'00010000' ; right part of digit 1 retlw b'00100000' ; right part of digit 2 retlw b'00110000' ; right part of digit 3 retlw b'00010000' ; right part of digit 4 retlw b'00110000' ; right part of digit 5 retlw b'00110000' ; right part of digit 6 retlw b'00010000' ; right part of digit 7 retlw b'00110000' ; right part of digit 8 retlw b'00110000' ; right part of digit 9 codeTensL addwf PCL, f retlw b'00111100' ; left part of digit 0 retlw b'00010000' ; left part of digit 1 retlw b'00111010' ; left part of digit 2 retlw b'00011010' ; left part of digit 3 retlw b'00010110' ; left part of digit 4 retlw b'00001110' ; left part of digit 5 retlw b'00101110' ; left part of digit 6 retlw b'00011000' ; left part of digit 7 retlw b'00111110' ; left part of digit 8 retlw b'00011110' ; left part of digit 9 codeHundredsR addwf PCL, f retlw b'00000111' ; right part of digit 0 retlw b'00000001' ; right part of digit 1 retlw b'00001011' ; right part of digit 2 retlw b'00001011' ; right part of digit 3 retlw b'00001101' ; right part of digit 4 retlw b'00001110' ; right part of digit 5 retlw b'00001110' ; right part of digit 6 retlw b'00000011' ; right part of digit 7 retlw b'00001111' ; right part of digit 8 retlw b'00001111' ; right part of digit 9 codeHundredsL addwf PCL, f retlw b'11000000' ; left part of digit 0 retlw b'01000000' ; left part of digit 1 retlw b'10000000' ; left part of digit 2 retlw b'11000000' ; left part of digit 3 retlw b'01000000' ; left part of digit 4 retlw b'11000000' ; left part of digit 5 retlw b'11000000' ; left part of digit 6 retlw b'01000000' ; left part of digit 7 retlw b'11000000' ; left part of digit 8 retlw b'11000000' ; left part of digit 9 codeHundredsS addwf PCL, f retlw b'01000000' ; left part of digit 0 retlw b'00000000' ; left part of digit 1 retlw b'01000000' ; left part of digit 2 retlw b'00000000' ; left part of digit 3 retlw b'00000000' ; left part of digit 4 retlw b'00000000' ; left part of digit 5 retlw b'01000000' ; left part of digit 6 retlw b'00000000' ; left part of digit 7 retlw b'01000000' ; left part of digit 8 retlw b'00000000' ; left part of digit 9 main clrf PORTA clrf PORTB clrf PORTC clrf PORTD bsf PORTD, 1 ; turn off the heater movlw b'00001001' ; enable ADC at AN2 movwf ADCON0 ; and left-justify the result bsf STATUS, RP0 ; change to BANK 1 movlw 7 movwf CMCON0 ^ 0x80 ; comparators off clrf ANSEL ^ 0x80 ; all inputs digital bsf ANSEL ^ 0x80, 2 ; excluding AN2: analog input movlw b'00010000' movwf ADCON1 ^ 0x80 ; ADC period = FOSC/8 movlw b'01100001' movwf OSCCON ^ 0x80 ; internal oscillator @4MHz clrf TRISA ^ 0x80 ; STEP 1: set I/O ports bsf TRISA ^ 0x80, 2 ; RA2 is analog input clrf TRISB ^ 0x80 clrf TRISC ^ 0x80 clrf TRISD ^ 0x80 bcf STATUS, RP0 bsf STATUS, RP1 ; switch to BANK 2 bsf LCDCON ^ 0x100, VLCDEN ; STEP 2: enable LCD bias voltage pins bcf LCDCON ^ 0x100, CS1 ; STEP 3: select clock source (FOSC/8092) bcf LCDCON ^ 0x100, CS0 bcf LCDCON ^ 0x100, LMUX1 ; STEP 4: select multiplex mode (static) bcf LCDCON ^ 0x100, LMUX0 bcf LCDPS ^ 0x100, WFT ; STEP 5: select waveform type (A) bcf LCDPS ^ 0x100, BIASMD ; STEP 6: select Bias mode bcf LCDPS ^ 0x100, LP3 ; STEP 7: select refresh rate bcf LCDPS ^ 0x100, LP2 ; 1:2 bcf LCDPS ^ 0x100, LP1 bsf LCDPS ^ 0x100, LP0 movlw 0xFF ; step 8: enable LCD segment lines movwf LCDSE0 ^ 0x100 movlw b'10011111' movwf LCDSE1 ^ 0x100 movlw b'11111110' movwf LCDSE2 ^ 0x100 clrf LCDDATA0 ^ 0x100 ; step 9: clear segment data registers clrf LCDDATA1 ^ 0x100 clrf LCDDATA2 ^ 0x100 bsf LCDCON ^ 0x100, LCDEN ; step 10: turn on the LCD driver module bcf LCDCON ^ 0x100, SLPEN ; enable LCD in sleep mode bcf STATUS, RP1 ; back to BANK 0 movlw 10 movwf coHigh ; start alarm at this value call greenLED loop bcf PORTD, 1 ; 14 msec heating cycle movlw 14 movwf del call delay bsf PORTD, 1 ; turn heater off movlw 250 ; 981 msec waiting loop movwf del call delay movlw 250 movwf del call delay movlw 250 movwf del call delay movlw 229 movwf del call delay bsf PORTD, 3 movlw 3 ; start data reading impulse movwf del call delay bsf ADCON0, GO ; start AD conversion btfsc ADCON0, GO ; conversion done? goto $-1 ; not yet - wait (takes about 25usec) bcf PORTD, 3 ; end of data reading loop ; PROCESSING THE SENSOR DATA movf ADRESH, w ; get the ADC value for processing btfss STATUS, Z addlw -1 ; correction to display 0 normally movwf coValue call bin2bcd call displayCO movf coHigh, w subwf coValue, w btfsc STATUS, C goto alarm call greenLED goto loop alarm call buzz call redLED goto loop bin2bcd ; converts the value in Wreg into BCD clrf hundreds clrf tens clrf units dig2 ; processing hundreds incf hundreds, f addlw -100 btfsc STATUS, C goto dig2 decf hundreds, f addlw 100 dig1 ; processing tens incf tens, f addlw -10 btfsc STATUS, C goto dig1 decf tens, f addlw 10 movwf units ; processing units return displayCO clrf displayCodes clrf displayCodes+1 clrf displayCodes+2 movf hundreds, w ; displaying hundreds btfss STATUS, Z ; display 100's if it non-zero goto disp100 movf tens, w ; now the 100's are 0, check the 10's btfss STATUS, Z goto disp10 ; display non-zero tens goto disp1 ; display just units if 10's are zero disp100 call codeHundredsS iorwf displayCodes, f movf hundreds, w call codeHundredsR iorwf displayCodes+1, f movf hundreds, w call codeHundredsL iorwf displayCodes+2, f disp10 movf tens, w ; displaying tens call codeTensR iorwf displayCodes, f movf tens, w call codeTensL iorwf displayCodes+2, f disp1 movf units, w ; displaying units call codeUnitsR iorwf displayCodes, f movf units, w call codeUnitsL iorwf displayCodes+1, f bsf STATUS, RP1 ; switch to BANK 2 movf displayCodes+2, w ; update LCD movwf LCDDATA2 ^ 0x100 movf displayCodes+1, w movwf LCDDATA1 ^ 0x100 movf displayCodes, w movwf LCDDATA0 ^ 0x100 bcf STATUS, RP1 ; back to BANK 0 return greenLED ; turn LED green bcf PORTC, 1 bsf PORTD, 0 return redLED ; turn LED red bcf PORTD, 0 bsf PORTC, 1 return buzz ; turn on buzzer for 100msec movlw 250 ; buzzer freq 2400Hz (T=416usec) movwf del buzzL bsf PORTB, 5 movlw 69 ; buzzer is on for 69*3=207usec movwf buzzT decfsz buzzT, f goto $-1 bcf PORTB, 5 movlw 69 ; buzzer is off for the second half-period movwf buzzT decfsz buzzT, f goto $-1 decfsz del, f goto buzzL return delay ; a delay for del milliseconds movlw 200 movwf delTMP delL nop ; this loop takes 5us*200 = 1ms nop ; for PIC16F917 @ 4 Mhz decfsz delTMP, f goto delL decfsz del, f goto delay return END