; This generates code for 4 digits output (HH:MM) ; Replace #UNDEFINE with #DEFINE for 6 digits output (HH:MM:SS) #UNDEFINE _6_digits ; The magic wand! V3.1 ; clock frequency = 32768Hz ; INT, TMR0 interrupts used. ; TMR0 is free running ; display triggered on INT (TB0) input low ; 9/2/2003 - Alex Lambardi ; Developped and assembled with MPLAB ; ############################################################################ ; 12/2006 ; Released under Creative Commons (CC) license ; Attribution-Noncommercial-Share Alike 2.5 License ; ; ############################################################################ include "p16f84.inc" LIST p=16F84 ; no copy protection, crystal type is XT, no power up delay timer, ; turn off watchdog timer __CONFIG (_CP_OFF & _XT_OSC & _PWRTE_OFF & _WDT_OFF) hour equ 0x0C ; hours min equ 0x0D ; minutes sec equ 0x0E ; seconds column equ 0x10 ; current column to display index equ 0x11 ; index to column table of beginning of chr to display w_temp equ 0x12 ; variable used for context saving status_temp equ 0x13 ; variable used for context saving ;; constants wand equ 0 ; wand button is at PORTB, bit 0 min_butt equ 0 ; minutes set button is at PORTA,0 hour_butt equ 1 ; hours set button is at PORTA,1 org 0x00 clrf PCLATH ; reset page bits call _initialize goto loop ISR org 0x04 ; interrupt service routine movwf w_temp ; save off current W register contents movf STATUS,w ; move status register into W register movwf status_temp ; save off contents of STATUS register bcf STATUS,RP0 ; Bank 0 btfss INTCON,T0IF ; TMR0 overflow ? goto ISR_INT ; no, must be button press call _inc_sec ; yes, increment seconds bcf INTCON,T0IF ; clear flag goto ISR_end ISR_INT btfss INTCON,INTF ; Button pressed ? goto ISR_end ; no, but should never get to here... call is_pressed ; yes, wand! bcf INTCON,INTF ; clear flag ISR_end movf status_temp,w ; retrieve copy of STATUS register movwf STATUS ; restore pre-isr STATUS register contents swapf w_temp,f swapf w_temp,w ; restore pre-isr W register contents retfie loop goto loop ; Just loop. Wait for interrupts is_pressed IFDEF _6_digits movf sec,W ; do units of seconds andlw 0x0F ; mask high nibble call do_digit swapf sec,W ; do tens of seconds andlw 0x0F ; mask high nibble call do_digit movlw 0x0A ; do colon call do_digit ENDIF movf min,W ; do units of minutes andlw 0x0F ; mask high nibble call do_digit swapf min,W ; do tens of minutes andlw 0x0F ; mask high nibble call do_digit movlw 0x0A ; do colon call do_digit movf hour,W ; do units of hours andlw 0x0F ; mask high nibble call do_digit swapf hour,W ; do tens of hours andlw 0x0F ; mask high nibble call do_digit return ; done ; do_digit ; Enter with W = the digit to display ; (0 to 9, 10 is colon) eval the index into ; the char table at 'get_clm' movwf index ; Save W bcf STATUS,C rlf index,F ; W = W*2 rlf index,F ; W = W*4 addwf index,W ; W = W*5 movwf index movlw 0x05 ; Each digit is 5 column movwf column ; column counter (5-1) do_digit_l ; Do 5 times movf index,W clrf PORTB ; Clear display at end of each column to 'visually' ; separate columns of LEDs call get_clm ; Get the LED pattern to display movwf PORTB incf index decfsz column goto do_digit_l clrf PORTB ; clear display at end of each digit return radix dec ; indirect addressing needs the table to be in the ; same 256 bytes block get_clm addwf PCL,F ; Enter with W equal x and ; will return the x-th value ; of the table in W DT 124,138,146,162,124 ; "0" DT 0,0,254,0,0 ; "1" DT 140,146,146,162,196 ; "2" DT 98,150,154,146,130 ; "3" DT 32,248,34,44,48 ; "4" DT 98,146,146,146,142 ; "5" DT 96,146,146,146,124 ; "6" DT 14,18,34,66,130 ; "7" DT 108,146,146,146,108 ; "8" DT 108,146,146,146,12 ; "9" DT 0,0,108,108,0 ; ":" radix hex _inc_sec btfss PORTA,hour_butt call _inc_hour btfss PORTA,min_butt call _inc_min incf sec,f ; now, increment seconds movf sec,W ; seconds->W andlw 0x0F ; mask most significant nibble of W sublw 0x0A ; units of sec == 10? btfss STATUS,Z ; return movf sec,W ; seconds->W andlw 0xF0 ; resets units of seconds and addlw 0x10 ; increment tens of seconds movwf sec ; store seconds movf sec,W ; seconds->W sublw 0x60 btfss STATUS,Z ; seconds == 60? return ; no, return clrf sec ; yes call _inc_min return _inc_min clrf sec ; clear seconds incf min,f movf min,W ; minutes->W andlw 0x0F ; mask most significant nibble of W sublw 0x0A ; units of sec == 10? btfss STATUS,Z return ; no, return movf min,W ; yes, minutes->W andlw 0xF0 ; resets units of minutes and addlw 0x10 ; increment tens of minutes movwf min ; store minutes movf min,W ; minutes->W sublw 0x60 ; minutes == 60? btfss STATUS,Z return ; no, return clrf min ; yes, reset minutes call _inc_hour return _inc_hour incf hour,f movf hour,W ; hours->W andlw 0x0F ; mask most significant nibble of W sublw 0x0A btfss STATUS,Z ; units of hour == 10? goto _ck_24 ; No, check if hour == 24 movf hour,W ; Yes, hours->W andlw 0xF0 ; resets units of minutes and addlw 0x10 ; increment tens of minutes movwf hour return _ck_24 movf hour,W ; hours->W sublw 0x24 ; hour == 24? btfsc STATUS,Z clrf hour ; yes, reset hours and return return ; no, simply return _initialize bcf STATUS, RP1 bsf STATUS, RP0 ; Select Bank 1 movlw 0x01 movwf TRISB ; PORTB[1..7] is output ; PORTB[0] is input movlw 0x03 movwf TRISA ; PORTA 0-1 are inputs movlw b'00000100' ; RBPU=0 (pull-ups on portB enabled), ; INTEDG=0 (falling edge INT on RB0), ; T0CS=0 (TMR0 uses internal clk source), ; T0SE=x (edge direction if T0CS set), ; PSA=0 (prescaler assigned to TMR0), ; prescaler=32 (TMR0 overflows once per sec) movwf OPTION_REG ; bcf STATUS,RP0 ; select bank 0 clrf TMR0 clrf sec clrf min clrf hour clrf INTCON ; zero interrupt control register bsf INTCON, T0IE ; enable TMR0 interrupt generation bsf INTCON, INTE ; enable INT(RB0) interrupt generation bsf INTCON, GIE ; global interrupt enable return ; fill remaining memory with "goto 0x00"s: in case ; the micro gets lost (!) it will meet one of these ; gotos eventually and synch again. fill (goto 0x000), (0x400-$) ; 0x400 is mem size, $ is current addr. END