Chunhee Song wrote:
>
>   Thank you, Tony for giving me an idea how to receive two byte data. I
> hope anyone has time to look at my code and point out what's wrong with
> it.
> I would like to receive 3 bytes. First two bytes are for duty cycle and the
> third one is for direction. I looked at my PIC book and piclist but
> couldn't find how to process input data. 7f+ is transferred from PC to
> pic. 7f is duty cycle and + is clockwise. Pic doesn't seem to take f as
> binary "1111" for sure.


        btfss pir1,rcif   ; got a char?
        goto noChar       ; no
;
; Data for duty cycle
; Eg. 7F = 127dec -> PC sends chr(127) not '7' + 'F'
;
        movf RCREG,W
        movwf DutyCycle
;
; Now get direction, should be following DutyCycle data
; 0 = Anti-clockwise, non zero = Clockwise
;
CharWt  btfss pir1,rcif    ; wait for next char
        goto CharWt

        movf RCREG,W       ; get direction byte
        btfss STATUS,Z
        goto ClockWise
;
; 0 = AntiClockwise move
;
        ....
;
; non 0 = Clockwise move
;
ClockWise
        ....


--
Best regards

Tony

http://www.picnpoke.com
mailto:sales@picnpoke.com