PIC newbie - took ages to program and i still have bugs

[Trickae]

Heres the error log

Clean: Deleting intermediary and output files. 
Clean: Deleted file "C:\Documents and Settings\\My Documents\speedtemp.mcs". 
Clean: Done. 
Executing: "C:\Program Files\Microchip\MPASM Suite\MPAsmWin.exe" /q /p16F84 "SPEED254.ASM" /l"SPEED254.lst" /e"SPEED254.err" 
Warning[207] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 140 : Found label after column 1. (SVNSEG) Warning[207] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 167 : Found label after column 1. (INTER) Error[113]   C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 319 : Symbol not previously defined (z) Error[113]   
C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 323 : Symbol not previously defined (z) Error[113]   
C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 362 : Symbol not previously defined (c) Error[113]   
C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 373 : Symbol not previously defined (c) Message[302] 
C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 501 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 503 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 505 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 707 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 709 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Error[113]   C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 729 : Symbol not previously defined (z) Error[113]   C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 732 : Symbol not previously defined (z) Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 953 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 955 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 957 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 958 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 960 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 961 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 963 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 968 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Message[302] C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 970 : Register in operand not in bank 0.  Ensure that bank bits are correct. 
Error[113]   C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 975 : Symbol not previously defined (z) Error[113]   C:\DOCUMENTS AND SETTINGS\\MY DOCUMENTS\SPEED254.ASM 1045 : Symbol not previously defined (c) Halting build on first failure as requested. 
BUILD FAILED: Tue Sep 25 12:53:21 2007

and my code's attached

Programming language: ASM PIC instruction set
PIC: PIC16F84

Any help would be greatly appreciated

[Archangel]

Hi Trickae,
Welcome, looks like you just joined today, Not too many people will open a zip file from someone they do not know well, so how about you break up that program and let us look at it in pieces if you cannot post it all in one without zipping it.
JS

[paul borgmeier]

>>took ages to program and i still have bugs

Interesting .... I found your code here with google

http://www.siliconchip.com.au/cms/at...month=November

[Trickae]

you've got me -

the code is legit no malware

the code is available with current kit based speed alert devices but I need to modify it for a personal project. I just Downloaded MPLAB today and ran the first couple of instructions and found a list of errors. I was expecting everything to be in order:

Heres the code in full:

part 1:

; File SPEED254.ASM changes from SPEED.ASM to allow speed readings up to 254km/h
; Uses assembly code for PIC16F84 microcontroller
; This program is for a car speed alarm. It utilises three 7-segment displays
; which show the set speed. The speed setting can be altered with up and down pushbutton 
; switches from 0 to 255km/h in 5km/h steps. When the speed of the vehicle reaches the set speed,
; the alarm sounds and an LED lights up. The alarm is a short beep beep sound while the LED 
; remains lit until the speed is reduced below the alarm speed or the alarm speed is increased 
; above the vehicles speed.
;
; A rotating magnet or magnets installed on the vehicles tail shaft or drive shaft
; trigger an inductive (coil) sensor to detect vehicle speed and this signal is detected via
; an interrupt in the processor.
;
; Calibration can be made by setting an alarm speed on the display and then bringing the 
; vehicle speed up to the alarm speed as shown on the vehicles speedometer. 
; The Calibrate switch is then pressed. The display will show CAL until
; calibrated. Display will show Err (error) if too few pulses or none are present while calibrating.  
; No calibration allowed in speedometer mode. 
;
; Each pressing the Mode switch will cycle between alarm speed indication, speedometer
; and off which disables the speed alarm. 
;
; Alarm indication occurs for speedometer and alarm speed modes. 
;
; Pressing the Up switch at power up will set the speed alarm for either a
; repeat warning of overspeed or single alarm. The repeat alarm will produce a tone every 
; 10-seconds until the speed goes below the setting or the speed setting is increased above
; the speed.
; 
; When pressing the Up switch at power up, a 'r' on the right display indicates repeat 
; alarm and a '-' indicates no-repeat alarm option.
;
; Pressing the Mode switch at power up will toggle the speed alarm with the speedometer on or off
; If the display shows an 'S' then the speedometer function will operate and a '-' indicates that
; the speedometer is off.
;
; Pressing the Down switch at power up will set the speed alarm threshold point either high or
; low. The low threshold means that the alarm will sound at the set speed and switch off
; when the speed goes 1km/h or less below this speed. The high threshold will set the alarm 
; when the speed is 1km/h or more above the set speed and go off for speeds at or below the 
; set speed. A high setting will be indicated by an 'H' and a low setting by an 'L'as shown during
; power up with the down switch pressed.
;  
; Processor pin allocations are as follows:
; RA0 Output disp1 driving transistor for common anode display
; RA1 Output disp2
; RA2 Output disp3
; RA3 Output for alarm
; RA4 Input from switches

; RB0 Input for wheel sensor (interrupt)
; RB1 c segment drive for seven segment LED display
; RB2 d segment drive
; RB3 e segment drive
; RB4 f segment drive
; RB5 a segment drive
; RB6 b segment drive
; RB7 g segment drive

; CPU configuration
; 	
	list P=16F84
	#include "p16f84.inc"
	__config _XT_OSC & _WDT_OFF & _PWRTE_ON

; Define variables at memory locations

; EEPROM DATA

EEPROM1		equ	H'00'	; non-volatile storage for display1
EEPROM2		equ	H'01'	; non-volatile storage for display2
EEPROM3		equ	H'02'	; non-volatile storage for display3
EEPROM4		equ	H'03'	; non-volatile storage to toggle repeat alarm feature and mode
EEPROM5		equ	H'04'	; non-volatile storage of LS byte of calibration number
EEPROM6		equ	H'05'	; non-volatile storage of MS byte of calibration number

; RAM

DISP1		equ	H'0C'	; working storage for Display1 value alarm speed mode
DISP2		equ	H'0D'	; working storage for Display2 value alarm speed mode
DISP3		equ	H'0E'	; working storage for Display3 value alarm speed mode
STATUS_TMP 	equ H'0F'	; temp storage for status during interrupt
W_TMP		equ	H'10'	; temporary storage for w during interrupt
VALUE_1		equ H'11'	; delay value storage			
VALUE_2		equ	H'12'	; delay value storage
FLAG_1		equ	H'13'	; flag, bit 0 = flag for closed switch, bit 1 for interrupt indicator
						; bit 2 for alarm tone required, bit 3 for tone duty cycle,
						; bit 4 alarm off, bit 5 overspeed, bit 6 EEPROM 
						; write repeat number, bit 7 for calibrate flag
FLAG_2		equ	H'14'	; alarm tone period settable from 00-FE 
FLAG_3		equ	H'15'	; alarm tone sequence 00000000=on,00000001=off,00000010=on >=00000011 off, 
						; use a more significant bit to set reocurrence, bit 6 or 7
REPEAT		equ	H'16'	; bit 0 working store repeat alarm flag stored in EEPROM4, bit 1 on/off flag
						; bit 1 on/off flag, bit 2 speedo/alarm select flag, bit 3 speedo on/off flag
						; bit 4 alarm threshold 
SPEED_EQV	equ	H'17'	; storage for speed equivalent (value of 5 per 5km/h) 160km/h=160
TEMP_1		equ	H'18'	; temporary working storage
TEMP_2		equ	H'19'	; temp storage
TIME_CNT1	equ	H'1A'	; counter for pulse count period
TIME_CNT2	equ	H'1B'	; counter for pulse count period
TIME_CNT3	equ	H'1C'	; working lsb calibration number stored in EEPROM5
TIME_CNT4	equ	H'1D'	; working msd calibration number stored in EEPROM6
PULSE_CNT	equ	H'1E'   ; counter for speed pulses compared with speed_eqv 
ERR_FLG		equ	H'1F'	; bit 0 is error flag for counter overrange during calibration
SPEEDO		equ	H'20'	; latched value for speedometer obtained from PULSE_CNT
SPEED1		equ	H'21'	; display1 value during speedometer mode
SPEED2		equ	H'22'	; display2 value during speedometer mode
SPEED3		equ	H'23'	; display3 value during speedometer mode
TEMP		equ	H'24'	; temporary register for BCD conversion
BCD_0		equ	H'25'	; decimal value MSD
BCD_1		equ	H'26'	; decimal packed BCD LS digits
BIN_0		equ	H'27'	; binary value for BCD conversion
CNT_8		equ	H'28'   ; counter for BCD conversion
TEMP_X		equ	H'29'	; temporary register for speed equivalent calculation
 
; preprogram EEPROM DATA
	
	ORG     2100
	DE	0x00, 0x06, 0x00	; preset EEPROM1-EEPROM3 ( initial speed setting is 60)
		DE	0x03			; set EEPROM4 (repeat alarm on bit 0 and set to on/off bit 1)
							; bit 2 speedo/set bit to set alarm mode, bit 3 speedo on
							; bit 4 alarm threshold low
		DE	0xB3, 0x11		; set calibration EEPROM5 & EEPROM6 (set to 100Hz = 160km/h
; calibration calculated out at 1.6s update time 160km/h = 160 pulses counted.
; 3.579545MHz/4/2/(256-100+2) = 353.1175us and require 4531Decimal for 1.6 sec or 11B3Hex 

; Program begins

; define reset and interrupt vector start addresses

	org	0			  	; start at address 0000h
	goto	MAIN		; normal service routines from Reset vector
	org     4			; interrupt vector 0004h, start interrupt routine here
	goto	INTER		; go to start of interrupt routine, bypass subroutines

; subroutine to get seven segment display data. (This is placed at front of programm to prevent computed
; goto crossing 256 bit boundary. *PCL control only over least significant 8-bits*) 
 
	SVNSEG	andlw	0x0F; remove most significant bits if present prevents value >16h
	addwf	PCL,f		; add value of display to program counter
	retlw 	B'10000000'	; 7-segment code 0 
	retlw 	B'10111100'	; 7-segment code 1
	retlw 	B'00010010'	; 7-segment code 2
	retlw 	B'00011000'	; 7-segment code 3
	retlw 	B'00101100'	; 7-segment code 4
	retlw 	B'01001000'	; 7-segment code 5
	retlw 	B'01000000'	; 7-segment code 6
	retlw 	B'10011100'	; 7-segment code 7
	retlw 	B'00000000'	; 7-segment code 8
	retlw 	B'00001000'	; 7-segment code 9

;*******************************************************************************************

- if need be i'll contact the developers website on why their code is ridden with bugs. Thanks for look at it.

[Trickae]

Part 2

; INTERRUPT
; interrupt from counter used to multiplex display
; this sucessively switches on Disp1, Disp2, Disp3 in sequence plus 
; blanking leading zeros on display for Disp2 and Disp3 for either 
; speedometer or set alarm speed modes
; uses internal timer to initiate display update
; also updates time period counters which set period of speed pulse counting
; checks speed against alarm setting
; speed sensor update

; start interrupt by saving w and status registers before altered by interrupt routine

	INTER	movwf	W_TMP	; w to w_tmp storage
	swapf	STATUS,w		; status to w
	movwf	STATUS_TMP		; status in status_tmp  

; which interrupt (INT or TMRO)

	btfsc	INTCON,T0IF		; TMRO overflow interrupt flag then goto litchk
	goto	LITCHK			; TMRO overflow so multiplex display
SENSOR	btfsc	INTCON,INTF	; INT interrupt flag set then goto speed
	goto	SPEED			; speed sensor signal update 
	goto	RECLAIM			; end of interrupt reclaim w and status

; multiplex display routine

LITCHK	btfsc	REPEAT,1	; check if speed alarm unit on or off
	goto	ALM_BY			; on so skip resetting alarm (alarm bypass)

; reset alarm function

	clrf	PULSE_CNT	; clear pulse counter so no alarm
	clrf	TIME_CNT1	; clear time counter 1
	clrf	TIME_CNT2	; clear time counter 2 	
ALM_BY	bcf	STATUS,RP0	; select bank 0
	movlw	D'100'		; speed up multiplex rate for suitable tone in piezo alarm (100
						; is used in calibration number calculation and for output freq)	
						; freq is 3.579545MHz/2/4/(256-100+2)/2 = 1.4159kHz
	addwf	TMR0,f		; add to timer registerand takes 2 cycles to start counting
	bcf	INTCON,T0IF		; clear TMRO interrupt flag
	bsf	FLAG_1,0		; indicate another interrupt has occurred
	btfsc	REPEAT,2	; check if speedometer or alarm speed mode
	goto 	SPD_LTE		; display update in speedometer mode 
	btfss	PORTA,0		; skip if display 1 not lit
	goto	LIT1		; display 1 lit
	btfss	PORTA,1		; skip if display 2 not lit
	goto	LIT2		; display 2 lit
	btfss	PORTA,2		; skip if display 3 not lit				
	goto	LIT3		; display 3 lit
	movlw	B'11111110'	; seven segments off
	movwf	PORTB
	bcf	PORTA,2			; no displays lit so set disp3 (used if error in output)
	goto 	LITCHK		; goto check which is lit now
LIT1	bsf	PORTA,0		; disp1 off
	movf	DISP3,w		; look at display3
	xorlw	0x00		; compare display3 with 0
	btfss	STATUS,Z	; skip if zero
	goto	NOBLNK		; do not blank display2
	movf	DISP2,w		; look at display2
	xorlw	0x00		; compare disp2 with 0
	btfss	STATUS,Z	; skip if 0
	goto	NOBLNK		; do not blank disp2
	movlw	B'11111110'	; 7-segment display off
	goto	BLANK		; blank disp2 when disp2 and disp3 = 0
NOBLNK	movf	DISP2,w		; disp2 to w
	call 	SVNSEG		; goto subroutine to get seven segment code 
BLANK	btfss	ERR_FLG,0	; calibrate error
	goto	CAL_M		; mid display
	movlw	B'10000110'	; set display for 'r' (Err)
	goto	LIT_r		; light an r
CAL_M	btfsc	FLAG_1,7	; calibrate flag skip if clear
	movlw	B'00000100'	; set display to show an A (for CAL) 
	btfss	REPEAT,1	; is speed alarm unit on or off, 1 is on 0 is off
	movlw	B'01111110'	; set 'g' segment on display 
LIT_r	movwf	PORTB		; seven segment value to portB
	bcf	PORTA,1		; disp2 powered
	goto	TIMECNT		; end of multiplex
LIT2	bsf	PORTA,1		; disp2 off
	movf	DISP3,w		; disp3 to w
	xorlw	0x00		; compare with 0
	btfss	STATUS,Z	; skip if zero
	goto 	SHOW		; show digit on disp3
	movlw	B'11111110'	; 7-segment display off
	goto	BLNK		; value to blank display
SHOW	movf	DISP3,w		; look at display3
	call	SVNSEG		; get 7-segment value
BLNK	btfss	ERR_FLG,0	; calibrate error
	goto	CAL_L		; Left display
	movlw	B'01000010'	; set display for 'E' (Err)
	goto	LIT_E		; light an E
CAL_L	btfsc	FLAG_1,7	; calibrate flag skip if clear
	movlw	B'11000010'	; set display to show a C (for CAL) 
	btfss	REPEAT,1	; is speed alarm unit on or off, 1 is on 0 is off
	movlw	B'01111110'	; set 'g' segment on display 
LIT_E	movwf	PORTB		; portB has seven-segment code 
	bcf	PORTA,2		; disp3 powered
	goto	TIMECNT		; end of multiplex
LIT3	bsf	PORTA,2		; disp3 off
	movf	DISP1,w		; disp1 to w
	call	SVNSEG
	btfss	ERR_FLG,0	; calibrate error
	goto	CAL_R		; Right display
	movlw	B'10000110'	; set display for 'r' (Err)
	goto	LIT_rr		; light an r
CAL_R	btfsc	FLAG_1,7	; calibrate flag skip if clear
	movlw	B'11100010'	; set display to show an L (for CAL) 
	btfss	REPEAT,1	; is speed alarm unit on or off, 1 is on 0 is off
	movlw	B'01111110'	; set 'g' segment on display 
LIT_rr	movwf 	PORTB
	bcf	PORTA,0		; disp1 powered
	goto	TIMECNT

; display update for speedometer mode

SPD_LTE btfss	PORTA,0	; skip if display 1 not lit
	goto	SPD_LT1		; display 1 lit
	btfss	PORTA,1		; skip if display 2 not lit
	goto	SPD_LT2		; display 2 lit
	btfss	PORTA,2		; skip if display 3 not lit				
	goto	SPD_LT3		; display 3 lit
	movlw	B'11111110'	; seven segments off
	movwf	PORTB
	bcf	PORTA,2			; no displays lit so set disp3 (used if error in output)
	goto 	SPD_LTE		; goto check which is lit now
SPD_LT1	bsf	PORTA,0		; disp1 off
	movf	SPEED3,w	; look at display3
	xorlw	0x00		; compare display3 with 0
	btfss	STATUS,Z	; skip if zero
	goto	NOBLNK1		; do not blank display2
	movf	SPEED2,w	; look at display2
	xorlw	0x00		; compare disp2 with 0
	btfss	STATUS,Z	; skip if 0
	goto	NOBLNK1		; do not blank disp2
	movlw	B'11111110'	; 7-segment display off
	goto	BLANK1		; blank disp2 when disp2 and disp3 = 0
NOBLNK1	movf	SPEED2,w	; disp2 to w
	call 	SVNSEG		; goto subroutine to get seven segment code 
BLANK1	movwf	PORTB		; seven segment value to portB
	bcf	PORTA,1		; disp2 powered
	goto	TIMECNT		; end of multiplex
SPD_LT2	bsf	PORTA,1		; disp2 off
	movf	SPEED3,w	; disp3 to w
	xorlw	0x00		; compare with 0
	btfss	STATUS,Z	; skip if zero
	goto 	SHOW1		; show digit on disp3
	movlw	B'11111110'	; 7-segment display off
	goto	BLNK1		; value to blank display
SHOW1	movf	SPEED3,w	; look at display3
	call	SVNSEG		; get 7-segment value
BLNK1	movwf	PORTB		; portB has seven-segment code 
	bcf	PORTA,2		; disp3 powered
	goto	TIMECNT		; end of multiplex
SPD_LT3	bsf	PORTA,2		; disp3 off
	movf	SPEED1,w	; disp1 to w
	call	SVNSEG
	movwf 	PORTB
	bcf	PORTA,0		; disp1 powered

; update time period counters for speed pulse counter

TIMECNT	btfsc	FLAG_1,7	; calibrate flag skip if clear (no calibrate)
	goto	CALBRAT		; calibrate switch pressed so do calibration
	movf	TIME_CNT4,w	; MS Byte of calibration value to w
	xorwf	TIME_CNT2,w	; compare MS Byte counter with calibration
	btfss	STATUS,z	; skip if equal
	goto	INC_CT1		; 
	movf	TIME_CNT3,w	; LS Byte of calibration value
	xorwf	TIME_CNT1,w	; compare LS byte counter with calibration
	btfss	STATUS,z	; skip if equal
	goto	INC_CT1		; 
	clrf	TIME_CNT1	; clear timer counter 1
	clrf	TIME_CNT2	; and timer 2
	movf	PULSE_CNT,w	; look at pulse counter value
	movwf	SPEEDO		; speedometer value latched pulse counter value

[Trickae]

part 3

; routine to convert speedo memory to speed 1, 2 & 3 display memory
	
	sublw	0xFF		; compare with maximum value (255km/h)
	btfsc	STATUS,Z	; is it at maximum
	goto	LIMIT		; maximum of 255 on display 

; convert speedo to BCD place in Speed 3,Speed 2 and Speed1	

	movf	SPEEDO,w	; look at speedo value
	movwf	BIN_0		; to binary register
	call	BCD		; convert to BCD
	movf	BCD_0,w		; ms digit
	movwf	SPEED3		; display MSD
	movf	BCD_1,w		; LS Digits
	andlw	0x0F		; mask bits 7-4
	movwf	SPEED1		; ls digit
	swapf	BCD_1,w		; look at ms nibble
	andlw	0x0F
	movwf	SPEED2		; middle digit
	goto	CK_SPD

LIMIT	movlw	0x08		; place 8 in speed1-3 memory so display -
	movwf	SPEED1		; - shows 888 for overrange speedometer
	movwf	SPEED2
	movwf	SPEED3
	
; check speed against alarm setting

CK_SPD	movf	SPEED_EQV,w	; speed equivalent value to w 
	btfsc	REPEAT,4	; skip if alarm threshold low
	addlw	0x01		; increase speed equiv by hysteresis value
	subwf	PULSE_CNT,w	; subtract speed equivalent from pulse counter	
	btfsc	STATUS,c	; if positive or zero (c=1) then sound overspeed alarm	
	goto 	SETALM
	
; add hysteresis (addition of 1 to pulse counter gives 1km/h hysteresis)

	movf	PULSE_CNT,w	; pulse counter value
	btfss	REPEAT,4	; skip if alarm threshold high
	addlw	0x01		; increase by factor for hysteresis (on to off alarm speed)
	movwf	PULSE_CNT
	movf	SPEED_EQV,w
	subwf	PULSE_CNT,w	; subtract speed equivalent from new pulse counter value
	btfsc	STATUS,c	; if positive or zero (c=1) then leave set alarm on
	goto	ALM_CL		; continue alarm
	goto	CLRALM		; clear alarm as below overspeed 
	
INC_CT1 incfsz	TIME_CNT1,f	; increase counter 1 skip if overflowed
	goto 	ALARM
	incf	TIME_CNT2,f	; increase counter 2 when counter 1 overflows
	goto 	ALARM

; calibrate time counters

CALBRAT	incfsz	TIME_CNT1,f	; increase counter 1 skip if overflowed
	goto	CMP_PLS
	incfsz	TIME_CNT2,f	; increase counter 2 on overflow skip if overflowed
	goto	CMP_PLS		; not overrange so compare pulse count with speed equiv
	bsf	ERR_FLG,0	; error flag set as counter 2 has overranged
	bcf	FLAG_1,7	; calibrate off flag
	goto	C_ALM
CMP_PLS	movf	PULSE_CNT,w	; pulse counter to w
	xorwf	SPEED_EQV,w	; compare pulse counter with speed equivalent (display value)	
	btfss	STATUS,Z	; skip if equal
	goto 	C_ALM
	
; store time counters TIME_CNT1 & 2 into TIME_CNT3 & 4 and into EEPROM5 & 6 - new calibration 

	movf	TIME_CNT1,w	; time counter 1 to w
	movwf	TIME_CNT3	; time counter 3 = 1
	movf	TIME_CNT2,w	; time counter 2 to w
	movwf	TIME_CNT4	; time counter 2 = 4
	bcf	FLAG_1,7	; calibrate flag clear, calibrate off
	
; clear alarm
	
CLRALM	clrf	PULSE_CNT	; clear pulse counter for recount
	clrf	TIME_CNT1	; clear time counter 1
	clrf	TIME_CNT2	; clear time counter 2 	
C_ALM	bcf	FLAG_1,5	; overspeed flag
	bcf	FLAG_1,4	; clear alarm off flag
	bsf	PORTA,3		; alarm output high 
	goto	ALARM		; continue program

; set alarm

SETALM	clrf	PULSE_CNT	; clear pulse counter for recount
	clrf	TIME_CNT1	; clear time counter 1
	clrf	TIME_CNT2	; clear time counter 2 	
	btfsc	FLAG_1,5	; is overspeed flag set. Skip if not
	goto	ALARM		; set so skip setting alarm again, wait till cleared
	bsf	FLAG_1,5	; overspeed flag
	bsf	FLAG_1,2	; set alarm tone flag
	bsf	FLAG_1,4	; set alarm off flag
	clrf	FLAG_2		; alarm tone period
	bcf	FLAG_1,3	; clear on off flag
	clrf	FLAG_3		; alarm tone sequence

; alarm tone routine generates a beep beep tone for over-speed 	

ALM_CL	clrf	PULSE_CNT
	clrf	TIME_CNT1	; clear time counter 1
	clrf	TIME_CNT2	; clear time counter 2 	
ALARM	btfss	FLAG_1,4	; alarm off flag
	goto	SENSOR		; alarm not required 
	incf	FLAG_2,f	; alarm tone period
	btfss	FLAG_1,2	; skip if alarm tone required	
	goto	RDFLG_2		; no alarm go to check sensor interrupt
	btfsc	FLAG_1,3	; alternate on and off flag for tone 
	goto	SET_OUT		; if flag set then stop tone on RA3 output
	btfsc	PORTA,3		; is alarm out low 
	goto	SET_OUT
	bsf	PORTA,3		; alarm out pin high 
	goto	CNT_SEQ
SET_OUT	bcf	PORTA,3		; alarm out pin low 
CNT_SEQ	bcf 	FLAG_1,3
	btfss	FLAG_3,0	; read alarm tone sequence (bit 0 low then alarm tone)
	goto	RDFLG_2	
	bsf	FLAG_1,3	; no tone
	bsf	PORTA,3		; alarm output high
	btfss	FLAG_3,1	; check count
	goto 	RDFLG_2
	bcf	FLAG_1,2	; alarm off
	bcf	PORTA,3		; alarm out low 
	goto 	SENSOR	
RDFLG_2	movf	FLAG_2,w	; read alarm tone period counter
	sublw	0xFE		; alarm tone on-time (FE = max) (00 = min)
	btfss	STATUS,C	; skip if less than on-time
	goto	SET_FLG
	goto 	SENSOR	
SET_FLG incf	FLAG_3,f	; next sequence
	clrf	FLAG_2		; start period count
	btfss	FLAG_3,7	; look at bit for repeat tone period, 7 is longest interval, 6 half the period etc
	goto	SENSOR		; if bit set then repeat alarm
	btfss	REPEAT,0	; skip if repeat flag set
	goto	SENSOR
	bsf	FLAG_1,2	; allow alarm again
	clrf	FLAG_3		; clear repeat bit 
	goto	SENSOR

; speed sensor update

SPEED	bcf	INTCON,INTF	; clear INT flag
	incfsz	PULSE_CNT,f	; increase pulse counter value for each speed sensor input
	goto	RECLAIM
	movlw	0xFF		; max value
	movwf	PULSE_CNT	; place max count in pulse counter do not allow overrange	
	
; end of interrupt reclaim w and status 

RECLAIM	swapf	STATUS_TMP,w	; status temp storage to w
	movwf	STATUS		; w to status register
	swapf	W_TMP,f		; swap upper and lower 4-bits in w_tmp
	swapf   W_TMP,w		; swap bits and into w register
	retfie			; return from interrupt