Microchip IO Dev Motor Esc-js_files 1.ASM

; ****************************************************************************
;* Inställningar
;****************************************************************************

	include 	"P16f873.inc"
	include 	"inkl.inc"

	__CONFIG	_WDT_OFF & _XT_OSC & _CP_OFF & _PWRTE_OFF
	__IDLOCS	0x1234

;****************************************************************************
;* Här startar programmet
;****************************************************************************

;--->Huvudprogrammet:

	ORG     0x000		; processor reset position
	GOTO    ProgramStart	; start

	cblock H'20'
	TMP1
	TMP2
	PULSLÄNGD
	endc

;****************************************************************************
;* interupt
;****************************************************************************
	org 0x0004
	RETFIE

;****************************************************************************
;* ProgramStart och huvudloop
;****************************************************************************

ProgramStart


	BANK1
	MOVLW	0x06
	MOVWF	ADCON1
	CLRF	TRISA
	MOVLW	B'00000011'
	MOVWF	TRISB
	BSF	OPTION_REG, 7
	CLRF	TRISC

	BANK0
	
	;PWM:
	; osc / 4 * Fpwm *  4 - 1
	; 1000000 / 5000 = fpwm = 2000 hz
	BSF	STATUS,RP0
	MOVLW	D'125'
	MOVWF	PR2
	BCF	STATUS,RP0

	;ställer in duty cycle:
	;01111101 = 125 * 0.00000025  * 4 
	;01000000 = 64
	MOVLW	B'01000000'
	MOVWF	CCPR1L
	BCF	CCP1CON,CCP1X
	BCF	CCP1CON,CCP1Y

	MOVLW	b'00000101'  ; prescaler = 4
	MOVWF	T2CON

	MOVF	CCP1CON, W
	ANDLW	b'00110000' 
	IORLW	b'00001111' 
	MOVWF	CCP1CON


HL	

	CLRF	PULSLÄNGD
	BTFSS	PORTB, 0	;Wait for a pulse to arrive
	GOTO	$-1		; Waiting...

	CALL	PAUS1MS		;Wait 1 ms before counting

	BTFSS	PORTB, 0	;Count as long as the pulse is active
	GOTO	PULSKLAR	; pulse has stopped, goto "pulsklar"
	INCF	PULSLÄNGD, F	; counting...
	GOTO	$-3		; 

PULSKLAR

	MOVF	PULSLÄNGD, W
	ADDLW	D'60'
	MOVLW	D'255'
	BTFSC	STATUS, C
	MOVWF	PULSLÄNGD

	MOVF	PULSLÄNGD, W	;SET PWM DUTY CYCLE!
	MOVWF	CCPR1L		

				
	BTFSC	STATUS, Z	;BRAKE IF DUTY CYCLE = 0%
	BSF	PORTC, 6
	BTFSS	STATUS, Z
	BCF	PORTC, 6

	
	GOTO	HL



;****************************************************************************
;* PAUS1MS
;****************************************************************************

PAUS1MS

	MOVLW	0xDB
	MOVWF	TMP1
	MOVLW	0x01
	MOVWF	TMP2
PAUS1MS_0
	DECFSZ	TMP1, f
	GOTO	$+2
	DECFSZ	TMP2, f
	GOTO	PAUS1MS_0

	RETURN

	END