LIST P=16F84 ;;; ;;; Clock I driver - LED clock ;;; 2/19/2000/tcy ;;; 2/29/2000/tcy updated ;;; Copyright (C) 2000, Theodore C. Yapo. All rights reserved. ;;; PORTA EQU 0x05 PORTB EQU 0x06 TRISB EQU 0x86 TRISA EQU 0x85 ; OPTREG EQU 0x81 INTCON EQU 0x0b STATUS EQU 0x03 CARRY EQU 0x00 RP0 EQU 0x05 W EQU 0x00 PCL EQU 0x02 TMR0 EQU 0x01 T0IF EQU 0x02 #define _Z STATUS, 2 #define _C STATUS, 0 ;;; ;;; configuration word ;;; ~Code Protect|~PWRT Enable|WDT enable| OSC selection 2 bits| ;;; CPD EQU 0xfff0; code protection PWRTE EQU b'1000'; code protect (inverted) WDTE EQU b'0100'; watchdog timer enable RC EQU b'0011'; external RC oscillator HS EQU b'0010'; high-speed crystal osc XT EQU b'0001'; standard crystal osc LP EQU b'0000'; low-power crystal osc __CONFIG CPD | LP CBLOCK 0x0C tick ; a tick is 1/32 second hour ; 0-11 minute_1 ; minutes mod 5 minute_5 ; minutes / 5 second_1 ; seconds mod 5 second_5 ; seconds / 5 porta_value ; accumulates lit LEDs portb_value ; accumulates lit LEDs minutes_button ; saves left button state for debounce hours_button ; saves right button state for debounce ENDC ;;; ;;; on reset, call the startup code ;;; ORG 0 ; reset vector GOTO STARTUP ;;; ;;; this ISR gets called on every TMR0 overflow interrupt (32Hz) ;;; increment the time, as appropriate ;;; display the time on the LEDs ;;; clear the TMR0 interrupt ;;; ORG 0x04 ; interrupt vector INCF tick ; incremented at 32 Hz BTFSS tick, 5 ; check if tick has exceeded 32 GOTO NO_SECOND ; nope, just display current time CLRF tick ; yes, a whole second has passed CALL INC_SECONDS ; increment to next second NO_SECOND: CLRF porta_value ; clear display CLRF portb_value ; clear display ;; if minutes are being adjusted, don't display hours ;; note that minute_button is 1 if not being pressed, > 1 if pressed DECF minutes_button, W BTFSS _Z GOTO SKIP_HOUR_DISPLAY ;; set the hour LED values into the temp registers MOVF hour, W CALL HAND_PORTA MOVWF porta_value MOVF hour, W CALL HAND_PORTB MOVWF portb_value SKIP_HOUR_DISPLAY: ;; if hours are being adjusted, don't display minutes ;; note that hour_button is 1 if not being pressed, > 1 if pressed DECF hours_button, W BTFSS _Z GOTO BLINK_MINUTE ;; if minutes are being adjusted, display minutes as solid ;; note that minute_button is 1 if not being pressed, > 1 if pressed DECF minutes_button, W BTFSS _Z GOTO SOLID_MINUTE ;; set the minute LED values only if tick bit 4 ;; this "blinks" the minute LED at 1Hz BTFSC tick, 4 GOTO BLINK_MINUTE SOLID_MINUTE: MOVF minute_5, W CALL HAND_PORTA XORWF porta_value ; XOR in the minute LED MOVF minute_5, W CALL HAND_PORTB XORWF portb_value ; XOR in the minute LED BLINK_MINUTE: ;; if minutes are being adjusted, don't display seconds ;; note that minute_button is 1 if not being pressed, > 1 if pressed DECF minutes_button, W BTFSS _Z GOTO BLINK_SECOND ;; if hours are being adjusted, don't display seconds ;; note that hour_button is 1 if not being pressed, > 1 if pressed DECF hours_button, W BTFSS _Z GOTO BLINK_SECOND ;; set the second LED values only if tick bit 2 is set ;; this "blinks" the minute LED at 4Hz BTFSC tick, 2 GOTO BLINK_SECOND MOVF second_5, W CALL HAND_PORTA XORWF porta_value ; XOR in the second LED MOVF second_5, W CALL HAND_PORTB XORWF portb_value ; XOR in the second LED BLINK_SECOND: ;; check for button press BSF STATUS, RP0 ;SELECT REGISTER BANK 1 BSF TRISB, 2 ; set RB2 to input BSF TRISA, 3 ; set RA3 to input BCF STATUS, RP0 ; select bank 0 ;; check minutes (must be pressed for at least 4 ticks) BTFSS PORTB, 2 ; test RB2 CLRF minutes_button ; button not pressed, clear count INCF minutes_button ; increment the minutes button count BTFSS minutes_button, 4; wait for press of at least 16 counts GOTO SKIP_MINUTE_INC MOVLW d'2' ; reset the count MOVWF minutes_button ; to 2 ;; increment 5_minutes CLRF second_1 ; clear seconds (1x) CLRF second_5 ; clear seconds (5x) CLRF minute_1 ; clear the 1-minute inc INCF minute_5 ; next minute (5x) MOVLW d'12' ; check for SUBWF minute_5, W BTFSS _Z ; check minutes overflow GOTO SKIP_MINUTE_INC ; minutes didn't overflow, so ripple ends CLRF minute_5 SKIP_MINUTE_INC: ;; check hours (must be pressed for at least 4 ticks) BTFSS PORTA, 3 ; test RA3 CLRF hours_button ; button not pressed, clear count INCF hours_button ; increment the hours button count BTFSS hours_button, 4 ; wait for press of at least 16 counts GOTO SKIP_HOUR_INC MOVLW d'2' ; reset the count MOVWF hours_button ; to '2' CALL INC_HOURS ; increment hour, if pressed SKIP_HOUR_INC: BSF STATUS, RP0 ;SELECT REGISTER BANK 1 BCF TRISB, 2 ; set RB2 to output BCF TRISA, 3 ; set RA3 to output BCF STATUS, RP0 ; select bank 0 ;; light the appropriate LEDs MOVF porta_value, W MOVWF PORTA MOVF portb_value, W MOVWF PORTB BCF INTCON, T0IF ; clear TMR0 interrupt RETFIE ; return from ISR ;;; ;;; INC_X routines: multiple entry points to increment seconds, minutes, hours ;;; with appropriate ripple updating INC_SECONDS: INCF second_1 ; increment to next second MOVLW d'5' SUBWF second_1, W BTFSS _Z ; check seconds overflow GOTO INC_DONE ; seconds didn't overflow, so ripple ends CLRF second_1 ; ripple continues, reset second_1 INCF second_5 ; next 5 second MOVLW d'12' SUBWF second_5, W BTFSS _Z ; check seconds overflow GOTO INC_DONE ; seconds didn't overflow, so ripple ends CLRF second_5 ; ripple continues, reset second_5 INC_MINUTES: INCF minute_1 ; next minute MOVLW d'5' SUBWF minute_1, W BTFSS _Z ; check minutes overflow GOTO INC_DONE ; minutes didn't overflow, so ripple ends INC_5MINUTES: CLRF minute_1 INCF minute_5 ; next minute MOVLW d'12' SUBWF minute_5, W BTFSS _Z ; check minutes overflow GOTO INC_DONE ; minutes didn't overflow, so ripple ends CLRF minute_5 INC_HOURS: INCF hour ; next hour MOVLW d'12' SUBWF hour, W BTFSS _Z ; check hours overflow GOTO INC_DONE ; hours didn't overflow, so ripple ends CLRF hour ; hours overflowed, so reset INC_DONE: RETURN ;;; ;;; --------------------------------------------------------------- ;;; ;;; ;;; startup code executes on reset ;;; STARTUP: CLRF PORTA ; clear port A CLRF PORTB ; clear port B BSF STATUS, RP0 ;SELECT REGISTER BANK 1 MOVLW 0x00 ; set portb to MOVWF TRISB ; all output MOVLW 0x00 ; set porta to MOVWF TRISA ; all outout MOVLW b'11001000' ; option MOVWF OPTREG BCF STATUS, RP0 ; select bank 0 MOVLW b'10100000' ; enable TMR0 interrupt MOVWF INTCON ;;; ;;; set time to 0:0:0 ;;; CLRF tick CLRF hour CLRF minute_1 CLRF minute_5 CLRF second_1 CLRF second_5 ;; clear debounce flags CLRF minutes_button CLRF hours_button ;;; ;;; the system is completely interrupt driven from the TMR0 overflow ;;; interrupt, so this loop simply spins until interrupted ;;; IDLE: GOTO IDLE ;;; ;;;----------------------------------------------------------------- ;;; ;;; ;;; return the value to output on PORTA for a specific "hand position" in W ;;; 0-11 HAND_PORTA: ADDWF PCL RETLW 0 ; 12 o'clock RETLW 0 ; 1 o'clock RETLW 0 ; 2 o'clock RETLW 0 ; 3 o'clock RETLW 0 ; 4 o'clock RETLW 0 ; 5 o'clock RETLW 0 ; 6 o'clock RETLW 0x8 ; 7 o'clock RETLW 0x4 ; 8 o'clock RETLW 0x2 ; 9 o'clock RETLW 0x1 ; 10 o'clock RETLW 0 ; 11 o'clock ;;; ;;; return the value to output on PORTB for a specific "hand position" in W ;;; 0-11 HAND_PORTB: ADDWF PCL RETLW 0x40 ; 12 o'clock RETLW 0x20 ; 1 o'clock RETLW 0x10 ; 2 o'clock RETLW 0x08 ; 3 o'clock RETLW 0x04 ; 4 o'clock RETLW 0x02 ; 5 o'clock RETLW 0x01 ; 6 o'clock RETLW 0 ; 7 o'clock RETLW 0 ; 8 o'clock RETLW 0 ; 9 o'clock RETLW 0 ; 10 o'clock RETLW 0x80 ; 11 o'clock ;;; ;;; END