;*******************************************************************************
;    Filename:	Servo206.asm                                                   *
;*******************************************************************************

	list		p=10f206
	#include	<p10f206.inc>
	
	__CONFIG   _CP_OFF & _MCLRE_OFF & _WDT_OFF & _IntRC_OSC

;***** VARIABLE DEFINITIONS ****************************************************
	cblock	0x08
		pulscntr
        loopcntr
	endc

#define	SERVO		GPIO,0

;***** INITIALIZE **************************************************************

	ORG		0x000
Init
	movwf	OSCCAL		; update register with factory calibration value
	clrf	GPIO
	clrf	CMCON0
	movlw	b'00111110'	; GP0 = output
	TRIS	GPIO
	movlw	b'11000110'	; prescaler set to 128, assigned to TMR0
	OPTION
    goto	Main

;***** SUBROUTINES *************************************************************
	
Dly
    call    Dly4us
Dly4us
	retlw	0x00

;****** MAIN LOOP **************************************************************

Main
    incf    loopcntr    ; Increase counter every loop
    bsf     SERVO       ; Start pulse
    movlw   0x60        ; Load TMR0 for 90 * 128us +/- 11ms ???
    movwf   TMR0        ;
    movlw   0x6E        ; Set left position (min 0x30)
    btfsc   loopcntr,5  ; Change position every 16 timerloops
    movlw   0x70        ; Set right position (max 0xD0)
    movwf   pulscntr
PlsLoop
    call    Dly         ; Delay 8us * cntr
    decfsz  pulscntr
    goto    PlsLoop
    bcf     SERVO       ; Stop pulse
TmrLoop
    movfw   TMR0        ; read TMR0 until 0x00
    btfss   STATUS,Z
    goto    TmrLoop
	goto	Main

;***** EPILOGUE ****************************************************************

	ORG		0x1F0
	DE		'S','e','r','v','o','2','0','6','-','0','0','2'
	END