; speedtrap.asm for the Microchip PIC 16C84/16F84 ; oscillator = XT 4MHz ; www.sciencezero.com - Bjørn Bæverfjord 2004-2006 ERRORLEVEL -305,-302,-224 ;Remove less than helpful warnings list p=16F84 include __config _XT_OSC & _WDT_OFF & _PWRTE_ON & _CP_OFF version equ .100 CBLOCK .12 ;Start of RAM in 16C84/16F84 cont1, cont2, cont3 disp1, disp2, disp3 temp1, temp2, temp3 shft1, shft2, shft3 key keymask cpcn ;Common Positive/Common Negative display unit trig temp dist teller frekv offset7seg dat ENDC org 0x00 ;Reset Vector call init goto main org 0x04 ;Interrupt Vector incf cont2 ;Only source of interrupts is TMR0 overflow so no need to check what caused the interrupt skpnz incf cont3 bcf INTCON,T0IF ;Clear overflow interrupt flag or we will be caught in an endless loop retfie ;**** Main program **** main movlw version ;Display program version movwf cont1 clrf cont2 clrf cont3 movlw .150 movwf temp call bin2dec wv call dispAll call pause2 decfsz temp goto wv mainL movlw .18 ;r movwf disp3 movlw .13 ;d movwf disp2 movlw .29 ;y movwf disp1 call readkey btfsc key,0 call armed ;Arm timer btfsc key,1 call prev ;Display previous measurements from EEPROM btfsc key,2 call cngUnit ;Change display unit btfsc key,3 call cngDist ;Change light gate spacing btfsc key,4 call cngTrig ;Trigger on 1 or 0 btfsc key,5 call debug ;Display state of RA3 and RA4 inputs call dispAll call pause2 goto mainL ;**** Wait for an event and time it **** armed call timer call calc movlw .32 call readEE addlw .2 ;Get next slot in EEPROM andlw .31 ;Wrap around movwf temp clrf cont3 movfw disp2 ;Store MSB movwf cont2 movwf EEDATA movfw temp movwf EEADR call writeEE movfw disp1 ;Store LSB movwf cont1 movwf EEDATA incf temp,W movwf EEADR call writeEE movfw temp ;Store Pointer movwf EEDATA movlw .32 movwf EEADR call writeEE call bin2dec ml2 call dispAll call pause2 call readkey movf key skpnz goto ml2 clrf key bsf keymask,0 ;Jump straight to Timer mode if Button 0 is pressed return ;**** Calculate **** calc movf unit skpz ;unit = uS, do nothing because our base unit is uS goto calc4 movfw cont1 movwf disp1 movfw cont2 movwf disp2 movfw cont3 movwf disp3 return calc4 movlw .1 xorwf unit,W skpz goto calc1 ;unit = mS so divide by 1000 movfw cont1 movwf disp1 movfw cont2 movwf disp2 movfw cont3 movwf disp3 movlw 0xE8 ;1000 = 03E8h movwf cont1 movlw 0x03 movwf cont2 clrf cont3 call div return calc1 movlw .2 xorwf unit,W skpz goto calc2 ;unit = U/S - s = ((100 000 * u ) / t) movlw 0xA0 ;A0h + (86h * 256) + (01h * 65536) = 100 000 movwf temp1 movlw 0x86 movwf temp2 movlw 0x01 movwf temp3 incf dist,W movwf temp call mul call div return calc2 movlw .3 xorwf unit,W skpz goto calc3 ;unit = U/H - s = ((100 000 * u ) / t) * (3600/1000) movlw 0x40 ;40h + (7Eh * 256) + (05h * 65536) = 360 000 movwf temp1 movlw 0x7E movwf temp2 movlw 0x05 movwf temp3 incf dist,W movwf temp call mul call div calc3 return ;**** 24x8 multiplication - disp3:disp2:disp1 = temp3:temp2:temp1 * temp mul clrf disp1 clrf disp2 clrf disp3 mulLoop movfw temp1 addwf disp1 movfw temp2 skpnc incfsz temp2,W addwf disp2 movfw temp3 skpnc incfsz temp3,W addwf disp3 decfsz temp goto mulLoop return ;**** 24/24 bit division - disp3:disp2:disp1 = disp3:disp2:disp1 / cont3:cont2:cont1 **** ;**** Remainder in temp3:temp2:temp1 - Original code by Tony Nixon, remainder probably buggy div movlw .24 movwf temp ;Bit count movfw disp3 movwf shft3 movfw disp2 movwf shft2 movfw disp1 movwf shft1 clrf disp3 clrf disp2 clrf disp1 clrf temp3 clrf temp2 clrf temp1 dloop clrc rlf shft1 rlf shft2 rlf shft3 rlf temp1 rlf temp2 rlf temp3 movfw cont3 subwf temp3,W skpz goto noCheck movfw cont2 subwf temp2,W skpz goto noCheck movfw cont1 subwf temp1,W noCheck skpc goto nogo movfw cont1 subwf temp1 skpc decf temp2 movfw temp2 xorlw .255 skpnz decf temp3 movfw cont2 subwf temp2 skpc decf temp3 movfw cont3 subwf temp3 setc nogo rlf disp1 rlf disp2 rlf disp3 decfsz temp goto dloop return ;**** Display previous 16 measurements **** prev movlw .32 call readEE movwf temp2 prev1 movlw .100 movwf temp call blank pw call pause2 call readkey movf key skpz goto prev3 decfsz temp goto pw prev3 movfw temp2 call readEE movwf cont2 incf temp2,W call readEE movwf cont1 clrf cont3 call bin2dec prev4 call dispAll call pause2 call readkey movf key skpnz goto prev4 btfss key,1 goto prev2 movfw temp2 addlw .254 andlw .31 movwf temp2 goto prev1 prev2 clrf key return ;**** Select trigger on 0 or 1 cngTrig movf trig skpz goto trig1 movlw .26 ;- movwf disp3 movwf disp2 movlw .27 ;L movwf disp1 goto trig2 trig1 movlw .25 ;_ movwf disp3 movwf disp2 movlw .28 ;T movwf disp1 trig2 call dispAll call pause2 call readkey movf key skpnz goto cngTrig btfss key,4 goto trig3 comf trig goto cngTrig trig3 movfw trig movwf EEDATA movlw .34 movwf EEADR call writeEE clrf key return ;**** Select display unit uS, mS, U/S, U/H cngUnit movf unit ;Microsecond uS skpz goto unit1 movlw .22 ;Blank movwf disp3 movlw .21 ;u movwf disp2 movlw .5 ;S movwf disp1 goto gotunit unit1 movlw .1 ;Milisecond mS (nnS) xorwf unit,W skpz goto unit2 movlw .20 ;n movwf disp3 movlw .20 ;n movwf disp2 movlw .5 ;S movwf disp1 goto gotunit unit2 movlw .2 ;Unit/Second xorwf unit,W skpz goto unit3 movlw .23 ;U movwf disp3 movlw .17 ;/ movwf disp2 movlw .5 ;S movwf disp1 goto gotunit unit3 movlw .23 ;U ;Unit/Hour movwf disp3 movlw .17 ;/ movwf disp2 movlw .24 ;H movwf disp1 gotunit call dispAll call pause2 call readkey movf key skpnz goto cngUnit btfss key,2 goto enduni incf unit,W andlw .3 movwf unit goto cngUnit enduni movlw .35 ;Write selected unit to EEPROM movwf EEADR movfw unit movwf EEDATA call writeEE clrf key return ;**** Select light gate spacing L01-L10 as a fraction of unit cngDist movlw .10 ;01 - 10 subwf dist,W skpc goto dist3 clrf dist goto cngDist dist3 incf dist,W movwf cont1 clrf cont2 call bin2dec movlw .27 ;L movwf disp3 gotdist call dispAll call pause2 call readkey movf key skpnz goto cngDist btfss key,3 goto enddis incf dist goto cngDist enddis movlw .36 ;Write selected spacing to EEPROM movwf EEADR movfw dist movwf EEDATA call writeEE clrf key return ;**** Read EEPROM - Address in W, data returned in W readEE banksel EEADR movwf EEADR ;Address to read banksel EECON1 bsf EECON1,RD banksel 0 movf EEDATA,W return ;**** Write EEPROM - Address inn EEADR, data in EEDATA writeEE banksel EECON1 clrf INTCON ;Disable all interrupts bsf EECON1,WREN movlw 0x55 movwf EECON2 movlw 0xAA movwf EECON2 bsf EECON1,WR waitEE btfsc EECON1,WR ;Wait for EEPROM write to complete (10ms typical) goto waitEE banksel 0 return ;**** Erase the first W bytes of EEPROM **** clearEE movwf temp clrL clrf EEDATA decf temp,W movwf EEADR call writeEE decfsz temp goto clrL return ;**** Display "Err" message and wait for keypress errMsg movlw .18 movwf disp1 movlw .18 movwf disp2 movlw .14 movwf disp3 call dispAll call pause2 call readkey movf key skpnz goto errMsg return ;**** Wait for RA3 trigger then count until RA4 triggers **** timer movf trig ;Check if trigger is to be done on 1 or 0 skpnz goto t1 btfsc PORTA,3 ;Display "Err" if not both gate inputs are low goto timeErr btfsc PORTA,4 goto timeErr goto t2 t1 btfss PORTA,3 ;Display "Err" if not both gate inputs are high goto timeErr btfss PORTA,4 goto timeErr t2 clrf TMR0 ;Clear Timer0 register clrf INTCON ;Disable interrupts and clear T0IF banksel OPTION_REG bcf OPTION_REG,T0CS ;TMR0 clock source select = Internal instruction cycle count bsf OPTION_REG,PSA ;Prescaler assignment = WDT = 1:1 banksel 0 call enDisp movlw .19 ;Display lightgate symbol [= =] call disp movlw .5 xorwf cpcn,W movwf PORTA bsf INTCON, T0IE ; Enable TMR0 interrupt bsf INTCON, GIE ; Enable all interrupts movf trig ;Check if trigger on 0 or 1 skpnz goto trgon0 movlw .2 ;Trigger on 1 tim1 btfss PORTA,3 ;Wait for gate 1 to trigger goto tim1 movwf TMR0 ;Timer0 is is disabled for 2 cycles after it is modified, so we start it at 2 (only valid for prescaler 1:1) clrf cont2 clrf cont3 tim2 btfss PORTA,4 ;Wait for gate 2 to trigger goto tim2 movfw TMR0 clrf INTCON ;Disable interrupts and clear T0IF movwf cont1 return trgon0 movlw .2 ;Trigger on 0 tim10 btfsc PORTA,3 ;Wait for gate 1 to trigger goto tim10 movwf TMR0 ;Timer0 is is disabled for 2 cycles aftere it is modified, so we start it at 2 (only valid for prescaler 1:1) clrf cont2 clrf cont3 tim20 btfsc PORTA,4 ;Wait for gate 2 to trigger goto tim20 movfw TMR0 clrf INTCON ;Disable interrupts and clear T0IF movwf cont1 call disDisp return timeErr call disDisp call errMsg return ;**** Read keypad and ignore any keys that are being held down **** readkey movlw .1 movwf temp1 keyloop xorlw .255 movwf PORTB xorlw .255 call pause8 btfss PORTB,7 goto gotkey addwf temp1,W movwf temp1 andlw .127 skpz goto keyloop clrf keymask comf keymask clrf key call blank return gotkey movwf key movwf temp1 comf temp1 movfw keymask andwf key movfw temp1 movwf keymask call blank return ;**** Wait for all keys to be released and update the display key0 call dispAll call pause2 clrf keymask comf keymask call readkey movf key skpz goto key0 return ;**** Debug - Displays the state of RA03 and RA04 **** debug clrf disp1 clrf disp3 movlw .16 movwf disp2 movlw .1 btfsc PORTA,3 movwf disp1 btfsc PORTA,4 movwf disp3 debugl call dispAll call pause2 call readkey movf key skpz return movlw .1 ;Only read input lines every 16th time so 1 and 0 does not visually merge and look like 0 on rapid changes addwf dat ;Make sure dat is not changed a in any of the functions skpdc ;Digit Carry happens on overflow of bit 3 (2^(3+1) = 16) goto debugl goto debug ;**** Convert cont2:cont1 binary to disp3:disp2:disp1 decimal **** bin2dec clrf disp1 clrf disp2 clrf disp3 movf cont1 skpnz goto doneC1 next1 incf disp1 movfw disp1 sublw .10 skpz goto doneDig clrf disp1 incf disp2 movfw disp2 sublw .10 skpz goto doneDig clrf disp2 incf disp3 movfw disp3 sublw .10 skpnz goto errCon doneDig decfsz cont1 goto next1 doneC1 movf cont2 skpnz goto doneC2 decf cont2 clrf cont1 goto next1 doneC2 return errCon movlw .16 ;Display -E- on numbers larger than 999 movwf disp1 movwf disp3 movlw 0x0E movwf disp2 return ;**** Display disp1:disp2:disp3 in turn on the 7 segment displays **** dispAll clrf PORTA movfw disp1 call disp movlw .1 xorwf cpcn,W movwf PORTA call enDisp call pause2 call disDisp clrf PORTA movfw disp2 call disp movlw .2 xorwf cpcn,W movwf PORTA call enDisp call pause2 call disDisp clrf PORTA movfw disp3 call disp movlw .4 xorwf cpcn,W movwf PORTA call enDisp call pause2 call disDisp call blank return ;**** Look up 7 segment data in the table and output it to the display disp movwf offset7seg movlw LOW ledLUT ;Get low 8 bits of address addwf offset7seg ;Do an 8-bit add operation movlw HIGH ledLUT ;Get high 5 bits of address btfsc STATUS,C ;Page crossed? addlw .1 ;Yes then increment high address movwf PCLATH ;Load high address in latch movf offset7seg,W ;Load computed offset in w reg call ledLUT xorlw .127 xorwf cpcn,W movwf PORTB return enDisp movlw B'11111000' ;Set display select lines to output to disable all display activity tris PORTA return disDisp movlw B'11111111' ;Set display select lines to input so no current can flow tris PORTA return ;**** Clear the display **** blank movfw cpcn clrf PORTA clrf PORTB return ;**** Pause for 256*3 uS **** pause2 clrf frekv wl12 nop decfsz frekv goto wl12 return pause8 nop nop nop nop nop nop nop nop return ;**** Initialise all ports and memory locations init clrf INTCON call disDisp movlw B'10000000' tris PORTB banksel OPTION_REG bcf OPTION_REG,NOT_RBPU ;Weak pullup on PORTB banksel PORTA call blank movlw .63 call readEE xorlw .197 skpz call clrAll ;Content of EE63 was not 197 so erase EEPROM and set default values movlw .33 ;Read config Common Cathode/Anode call readEE movwf cpcn movlw .34 ;Read config Trigger call readEE movwf trig movlw .35 ;Read config Display call readEE movwf unit movlw .36 ;Read config Distance call readEE movwf dist clrf keymask comf keymask call readkey btfsc key,0 call clrAll ;On startup - Button 0 - Clear everything in EEPROM btfsc key,1 call clr16 ;On startup - Button 1 - Clear previously recorded values and position byte btfsc key,2 call selDisp ;On startup - Button 2 - Select display type Common cathode or Common anode return ;**** Clear all 64 bytes of EEPROM and enter default values clrAll movlw .64 call clearEE movlw .0 ;Default value cpcn = 0 movwf EEDATA movlw .33 movwf EEADR call writeEE movlw .255 ;Default value Trig on 1 movwf EEDATA movlw .34 movwf EEADR call writeEE movlw .2 ;Default value Unit = U/S movwf EEDATA movlw .35 movwf EEADR call writeEE movlw .2 ;Default value Distance = 0.3 movwf EEDATA movlw .36 movwf EEADR call writeEE movlw .197 ;Mark EEPROM as cleared. 197 is a magic number thought not rarely arise in EEPROM by accident movwf EEDATA movlw .63 movwf EEADR call writeEE movlw 0x0C ;C movwf disp3 movlw .27 ;L movwf disp2 movlw .18 ;r movwf disp1 call key0 return ;**** Select Common Anode or Common Cathode displays selDisp clrf keymask comf keymask call readkey btfss key,2 ;Invert Common Anoded/Cathode displays goto doneSD movlw .123 movwf cont1 clrf cont2 call bin2dec call dispAll call pause2 incf dat skpnz comf cpcn goto selDisp doneSD movlw .33 movwf EEADR movfw cpcn movwf EEDATA call writeEE return ;**** Clear the 16 recorded values stored in EEPROM clr16 movlw .33 ;32 data bytes + position byte call clearEE movlw 0x0C ;C movwf disp3 movlw .1 ;1 movwf disp2 movlw .6 ;6 movwf disp1 call key0 return ;**** Table for converting a character to 7 segment display data **** org 0x300 ;The last 256 bytes of program memory belongs to the look-up table ledLUT addwf PCL ; gfedcba retlw B'0111111' ;0 retlw B'0000110' ;1 retlw B'1011011' ;2 retlw B'1001111' ;3 retlw B'1100110' ;4 retlw B'1101101' ;5 retlw B'1111101' ;6 retlw B'0000111' ;7 retlw B'1111111' ;8 retlw B'1101111' ;9 retlw B'1110111' ;A 10 retlw B'1111100' ;B 11 retlw B'0111001' ;C 12 retlw B'1011110' ;D 13 retlw B'1111001' ;E 14 retlw B'1110001' ;F 15 retlw B'1000000' ;- 16 retlw B'1010010' ;/ 17 retlw B'1010000' ;r 18 retlw B'0001001' ;= 19 light gate symbol retlw B'1010100' ;n 20 retlw B'0011100' ;u 21 retlw B'0000000' ; 22 blank retlw B'0111110' ;U 23 retlw B'1110110' ;H 24 retlw B'0001000' ;_ 25 retlw B'0000001' ;- 26 retlw B'0111000' ;L 27 retlw B'0110001' ;T 28 retlw B'1101110' ;y 29 ; gfedcba fill (retlw B'10101010'),(0x3ff-$)+1 ;Fill the rest of memory with an invalid display code end ; Segment Identification ; ; aaaaa ; f b ; f b ; ggggg ; e c ; e c ; ddddd . ; RA0(17) -> Select display 1 ; RA1(18) -> Select display 2 ; RA2(1) -> Select display 3 ; RA3(2) <- Light gate 1 ; RA4(3) <- Light gate 2 ; RB0(6) -> Display segment a ; RB1(7) -> Display segment b ; RB2(8) -> Display segment c ; RB3(9) -> Display segment d ; RB4(10) -> Display segment e ; RB5(11) -> Display segment f ; RB6(12) -> Display segment g ; RB7(13) <- Button multiplexer (RB0-RB6) ;Pin-out of a noname 7 segment display ;1 2 3 4 5 ;g f _ a b ;e d + c . ; Buttons (R0-R6 -> R7) ; 0 Arm timer ; 1 Previous reading (from eeprom) ; 2 Display unit uS, nnS, U/S, U/H ; 3 Light gate spacing d01 - d10 ; 4 Trigger on 0 or 1 ; 5 Debug (show state of gate inputs) ;EEPROM content ;0-31 - The 16 last timings (cont2:cont1) ;32 - Position of last timing value stored ;33 - cpcn ;34 - Trigger low->high or high->low ;35 - Display Unit uS, nnS, U/S, U/H ;36 - Distance d1-d10 ;63 - Run before = 197