; $Id: clock.asm,v 1.13 2001/05/13 21:45:11 dogcow Exp dogcow $ ; ; General notes: this is dervied from the 99 minute timer code, but I've ; whacked close to every single line of code there, so it's MINE! MINE! ; ; The "check 8 seconds" doesn't get triggered on second 00; this reduces the ; maximum number of ticks/minute to 7. (This can be fixed by moving the ; incf halfseconds, f to 'chkforminute' instead of right at 'checkseconds'.) ; list p=16f84a, r=dec include "p16f84a.inc" org 0 goto init ;power-on-reset goto start ;interrupt vector (shouldn't be called) numticksperminute equ 6 ; how many ticks occur in a minute? regbase equ 0ch ; vars start at 0ch on the 16C84. oldkey equ regbase+0 newkey equ regbase+1 counter_4ms equ regbase+2 ;incremented every 4 msec counter_100ms equ regbase+3 ;incremented every 100 msec halfseconds equ regbase+4 minutes equ regbase+5 hours equ regbase+6 minuteticks equ regbase+7 hourticks equ regbase+8 tmr_comp equ regbase+9 ;tmr0 comparator register scrtch0 equ regbase+10 led1 equ regbase+11 led2 equ regbase+12 ; pin assignments: ; output: ; ra1,2,3 - minute/hour/ageofman outputs (to power Q's/solenoids) ; rb0,1,2,3 - minute/tenminute/hour/resettozero inputs (from pushbuttons) ; rb4,5,6 - strobe,clock,data outputs (to 4094s) ; ra0, rb7: unused ; ; bit positions inside digit_inc and newkey minute_inc equ 0 ;aka rb0 tenminute_inc equ 1 ;aka rb1 XXX NOT CURRENTLY IMPLEMENTED XXX hour_inc equ 2 ;aka rb2 reset_minutes equ 3 ;aka rb3 button_PORT equ PORTB keymask equ 0fh ; mask for lower keys ; the 4094 8-bit shift registers strobe_4094 equ 4 ;aka rb4 clock_4094 equ 5 ;aka rb5 data_4094 equ 6 ;aka rb6 shiftreg_PORT equ PORTB ; the solenoids that kick the escapements ; note that since the output solenoids are on their own PORT, we can do ; bcf/bsfs without hitting a read latch we care about. minute_sol equ 1 ;aka ra1 hour_sol equ 2 ;aka ra2 aom_sol equ 3 ;aka ra3 (age of man relay) solenoid_PORT equ PORTA ;7 segments decoded data. lo is segment on & hi is segment off get_seg addwf PCL, f ; ABCDEFGPb retlw 00000011b ;0 retlw 10011111b ;1 retlw 00100101b ;2 retlw 00001101b ;3 retlw 10011001b ;4 retlw 01001001b ;5 retlw 01000001b ;6 retlw 00011111b ;7 retlw 00000001b ;8 retlw 00011001b ;9 retlw 00010001b ;A retlw 11000001b ;b retlw 01100011b ;C retlw 10000101b ;d retlw 01100001b ;E retlw 01111001b ;F dec_pt equ 11111110b ;decimal point bit getticksperhour movf hours, w addwf PCL, f retlw 5 ;00 retlw 4 ;01 retlw 3 ;02 retlw 4 ;03 retlw 2 ;04 retlw 2 ;05 retlw 2 ;06 retlw 2 ;07 retlw 2 ;08 retlw 2 ;09 retlw 4 ;10 retlw 4 ;11 retlw 4 ;12 retlw 3 ;13 retlw 3 ;14 retlw 1 ;15 retlw 2 ;16 retlw 2 ;17 retlw 3 ;18 retlw 3 ;19 retlw 2 ;20 retlw 4 ;21 retlw 4 ;22 retlw 5 ;23 ; clear vars, ; set the ports to the proper impedence/io states, ; and frob prescaler to make timer0 run more slowly. ; init clrf hours clrf minutes clrf halfseconds start clrf oldkey clrf newkey clrf counter_4ms clrf counter_100ms ; set up the TRIS flags properly - have to bank-switch to proper region bsf STATUS, RP0 ; clrf TRISA ;lazy way "all ports are out" movlw 00001111b ;ports 0-3 are pb input movwf TRISB ; movlw 11000011b ;tmr0 enable with 1:16 prescaler movwf OPTION_REG ;see 2.2.2.2 in 16f84a datasheet clrf INTCON ;we don't want no steenking interrupts! ; bcf STATUS, RP0 ;bank-switch back ; and now, the timer bits clrf TMR0 ; why 250? each isn takes 4 cycles, so with a 4mhz processor, 1m isn/sec. ; with 1:16 prescaler, 16 * 250 / 1e6 Hz = 4e-3 seconds movlw 250 movwf tmr_comp goto resetticks ;have to populate ticks/hour&min ; ; and now, the main main time-wasting loop ; main movf tmr_comp, w ;is tmr0 = tmr_comp (4 msec over?) xorwf TMR0, w btfss STATUS, Z ;skip if = 250 goto main movlw 250 addwf tmr_comp, f ;update 4 msec compare register incf counter_4ms, f movlw 25 xorwf counter_4ms, w ;is 4ms * 25 = 100ms over ? btfss STATUS, Z ;skip if = 100ms goto main clrf counter_4ms ; 100ms over - time to check the status of the buttons! ; ; in order for a button to register, the key has to have been pressed ; for two successive 100ms intervals. We invert the active-low ; bits to positive so we can just AND oldkey and newkey together. ; check_buttons movf newkey, w movwf oldkey ; save old key comf button_PORT, w ; invert keys, since active low movwf newkey ; save now active-high key ; clrf keyaction andwf oldkey, f ; and AND'em to oldkey in place ; movlw keymask ; andwf oldkey, f ; just in case we pick up spurious bits ; (I hope this ain't really needed) ; ; and back to the horribly important business of keeping the counters up incf counter_100ms, f movlw 5 xorwf counter_100ms, w ;is 500ms done? btfss STATUS, Z goto main ;nope, 500ms ain't done. ; ; huzzah! welcome to 500ms. ; all sorts of crap gets done here: ; turn off solenoids if it's an odd halfsecond; ; do clock ticks on multiples of 8 seconds ; ; do minute->hour rollover and stuff if needed; ; and finally, display the time on the LEDs. ; clrf counter_100ms ;half a second over! movf oldkey, w ;have buttons been pressed? btfsc STATUS, Z goto checkseconds ; nope. ; so, we got button presses. buttons are active high. btfss oldkey, minute_inc goto chkhourbutton ; advance the minute! clrf halfseconds incf minutes, f goto chkminuterollover chkhourbutton btfss oldkey, hour_inc goto chkresetbutton incf hours, f ; inc hours, don't reset minute/hsec goto chkhourrollover chkresetbutton btfss oldkey, reset_minutes goto checkseconds clrf halfseconds clrf minutes goto chkhourrollover ; and this'll fall into checkseconds incf halfseconds, f ; if it's a odd half-second, turn off solenoids movlw 1 andwf halfseconds, w btfsc STATUS,Z goto check8secs ; actually turn off the solenoids bcf solenoid_PORT, minute_sol bcf solenoid_PORT, hour_sol ; check and see if a multiple of 8 seconds has elapsed check8secs movlw 15 andwf halfseconds, w btfss STATUS, Z goto chkforminute ; nope, don't worry about tocking ; tick if need be... movf minuteticks, f btfsc STATUS, Z goto checkhourticks ;nope, no minute ticks needed bsf solenoid_PORT, minute_sol decf minuteticks, f checkhourticks movf hourticks, f btfsc STATUS, Z goto chkforminute ;nope, no hour ticks needed bsf solenoid_PORT, hour_sol decf hourticks, f ; chkforminute movlw 120 xorwf halfseconds, w ;is 1 minute over ? btfss STATUS, Z goto displaytime ;nope. ; roll over minutes, and possibly hours clrf halfseconds incf minutes, f chkminuterollover movlw 60 xorwf minutes, w ;is 60 minutes over? btfss STATUS, Z goto resetticks ;reset minutetick & hourtick ; update hours incf hours, f chkhourrollover movlw 24 xorwf hours, w btfsc STATUS, Z clrf hours resetticks call getticksperhour movwf hourticks movlw numticksperminute movwf minuteticks ; and fall through to "display the time on the LEDs" displaytime movlw 255 ;all segs off movwf led1 movf hours, w call get_seg movwf led2 movlw 1 andwf halfseconds, w btfss STATUS,Z goto xmittoleds movlw 15 andwf minutes, w call get_seg movwf led2 swapf minutes, w andlw 15 call get_seg movwf led1 ;transmit data from scrtch1 thr scrtch1 to display circuit (msb first). xmittoleds movlw 16 ;no of bit to tx movwf scrtch0 xmitloop rlf led2, f rlf led1, f btfsc STATUS, C ;data hi if cy=1 else lo goto toggle_hi bcf shiftreg_PORT, data_4094 goto toggle_clock toggle_hi bsf shiftreg_PORT, data_4094 toggle_clock nop ;delay nop bsf shiftreg_PORT, clock_4094 nop nop bcf shiftreg_PORT, clock_4094 nop nop decfsz scrtch0, f ;next bit goto xmitloop bsf shiftreg_PORT, strobe_4094 nop bcf shiftreg_PORT, strobe_4094 bcf shiftreg_PORT, data_4094 goto main ; __CONFIG _RC_OSC & _WDT_OFF & _PWRTE_ON & _CP_OFF end