LIST   P=PIC12F683
	INCLUDE  P12F683.INC
     __CONFIG	_HS_OSC & _MCLRE_OFF & _WDT_OFF 


;***********************************************************
; Definition of valuables
;***********************************************************

COUNT	EQU 20H
COUNT1	EQU 21H
COUNT2	EQU 22H
COUNT3	EQU 23H
COUNT4	EQU 24H
ADCRES	EQU	25H
TEMP	EQU 26H
W_TEMP	EQU 27H
S_TEMP	EQU 28H
PWMVAL	EQU 29H
INT_DIV	EQU	2AH
PWM_AIM	EQU	2BH
AIM_SEL	EQU 2CH




	ORG 0
	goto INIT

	org 4

INTERRUPT
	movwf	W_TEMP
	movf	STATUS,W
	movwf	S_TEMP
	BSF		STATUS,RP0  
	movlw	0fbh
	ANDWF	INTCON,F
	bcf		STATUS,RP0  
	
	CALL	ADCONV

	INCF	INT_DIV,F
	movf	INT_DIV,W
	sublw	01h
	btfsc	STATUS,Z
	GOTO	INT_MAIN
	
	movf	S_TEMP,W
	movwf	STATUS		
	movf	W_TEMP,W
	retfie

INT_MAIN
	CLRF	INT_DIV
	movf	ADCRES,W

	CALL	ADCONV

	movf	ADCRES,W
	subwf	PWM_AIM,W
	btfsc	STATUS,Z
	GOTO	OK_PWM

	movf	ADCRES,W
	subwf	PWM_AIM,W
	btfsc	STATUS,C
	GOTO	DEC_PWM
	GOTO	INC_PWM
;850mA->76, 700mA->61, 500mA->46, 200mA->1C

PWM_ADJ_END
	movf	S_TEMP,W
	movwf	STATUS		
	movf	W_TEMP,W
	retfie
	
INC_PWM					;Decrease PWM Duty
	INCF	PWMVAL,F
	btfsc	STATUS,Z
	DECF	PWMVAL,F
	CALL	SETPWM
	BSF		GPIO,0
	GOTO	PWM_ADJ_END
DEC_PWM	 				;Increase PWM Duty
	DECF	PWMVAL,F
	BTFSC	STATUS,Z
	INCF	PWMVAL,F
	CALL	SETPWM
	BCF		GPIO,0
	GOTO	PWM_ADJ_END

OK_PWM
	GOTO	PWM_ADJ_END
	BTFSS	GPIO,0
	GOTO	OK_PWM2
	BCF		GPIO,0
	GOTO	PWM_ADJ_END
OK_PWM2
	BSF		GPIO,0
	GOTO	PWM_ADJ_END
	

SHUTDOWN
	movlw	0ffh
	movwf	PWMVAL
	movlw	3fh
	movwf	CCPR1L
	movlw	3fh
	movwf	CCP1CON
	return

SETPWM
	movf	PWMVAL,W
	movwf	TEMP
	rrf		TEMP,F
	bcf		STATUS,C	
	rrf		TEMP,W
	andlw	3fh
	movwf	CCPR1L
	movf	PWMVAL,W
	movwf	TEMP
	SWAPF	TEMP,W
	andlw	30h
	iorlw	0fh
	movwf	CCP1CON
	return

ADCONV
	movlw	85h
	movwf	ADCON0
	CALL	TIME100
	BSF		ADCON0,GO
ADC_LOOP
	btfsc	ADCON0,GO
	goto	ADC_LOOP
	BSF		STATUS,RP0  
	movf	ADRESL,W
	BCF		STATUS,RP0  
	movwf	ADCRES

	movf	ADCRES,W
	sublw	07dh
	btfss	STATUS,C
	CALL	SHUTDOWN
	movf	ADRESH,W
	addlw	0
	btfss	STATUS,Z
	CALL	SHUTDOWN
	
	return

;***********************************************************
; I/O pins Initialize
;***********************************************************
INIT

	movlw	04h
	movwf	T2CON
	movlw	3fh		;PWM mode
	movwf	CCP1CON
	movlw	0ffh
	movwf	CCPR1L
	CLRF	PWMVAL
	movlw	04h
	movwf	ADCON0
	clrf	CMCON0

	BSF		STATUS,RP0  
	movlw	b'11111010'
	movwf	TRISIO
	movlw	03fh
	movwf	PR2
	movlw	043h
	movwf	OPTION_REG
	movlw	0a0h
	movwf	INTCON
	movlw	62h
	movwf	ANSEL
	bcf		STATUS,RP0  		


;***********************************************************
; MAIN program
;***********************************************************
	
;900mA->7D, 850mA->76, 700mA->61, 500mA->46, 200mA->1C, 150mA->11
	movlw	11h
	movwf	PWM_AIM
		
MAIN
	BTFSS	GPIO,3
	GOTO	HI_MODE
	GOTO	LO_MODE
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	

HI_MODE
	movlw	61h
	movwf	PWM_AIM
	goto 	MAIN	
LO_MODE
	movlw	11h
	movwf	PWM_AIM
	goto 	MAIN	


	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	goto 	MAIN	
	



;***********************************************************
;	Timer Sub routines
;***********************************************************

TIME100
     MOVLW  0AH
     MOVWF  COUNT
     NOP
     NOP
LOOP
     DECFSZ COUNT,F
     GOTO  LOOP
     RETURN

TIME10M
     MOVLW  0F4H
     MOVWF  COUNT1
     NOP
     NOP
LOOP1
     CALL   TIME100
     DECFSZ  COUNT1,F
     GOTO   LOOP1
     RETURN

TIME1S
     MOVLW  0FFH
     MOVWF  COUNT2
     MOVLW  24H
     MOVWF  COUNT3
     MOVLW  03H
     MOVWF  COUNT4
     NOP
LOOP2
     CALL  TIME10M
     DECFSZ COUNT2,F
     GOTO  LOOP2
LOOP3
     CALL  TIME100
     DECFSZ COUNT3,F
     GOTO  LOOP3
LOOP4
     DECFSZ COUNT4,F
     GOTO  LOOP4
     RETURN



end