Grey code to decimal sketch

[Corey Renner]

Anyone got an arduino sketch to convert gray code to decimal?  This seems like it would be a common thing to do, but I haven't found anything.

cheers,

c

Blog:

http://coreyrenner.tumblr.com/

 

YouTube Channel:

http://www.youtube.com/user/vandal968

[Robert Bell]

http://bildr.org/2012/08/rotary-encoder-arduino/

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[Corey Renner]

Very helpful, thanks Robert.

cheers,

c

Blog:

http://coreyrenner.tumblr.com/

 

YouTube Channel:

http://www.youtube.com/user/vandal968

[Lee Studley]

Ignore the examples I gave. I don't know what I was thinking,but they aren't gray codes.

[Lee Studley]

Actually it did work: I was putting in the binary when I should have been putting in the gray code
Here's the example combined with bin2gry  then  gry2bin
this is using Microchip's mplab simulator.
==================================

 list      p=12c509A        ; list directive to define processor
    #include <p12c509A.inc>    ; processor specific variable definitions

    __CONFIG   _CP_OFF & _WDT_OFF & _MCLRE_OFF & _IntRC_OSC


    cblock 0x10
     gry_in
     bin_out
     count
     temp
    endc

    ORG     0x000           ; coding begins here
reset   movwf   OSCCAL          ; update register with factory cal value
    goto    init

init       clrf    STATUS            ;
    clrf    GPIO            ;
    movlw    b'00101001'     ;
    OPTION                ;
    movlw   0x10        ;
    TRIS    GPIO            ;

    clrf    GPIO            ; initialize the output bits on GPIO

;=====above is just pic setup=====================

    ; setup for conversion
    movlw 0x76 ;  0x76(hex)-->0x4D(gray) expected result

;================================
; Binary to Gray Code routine
; entry: with binary in w
; exit with Grey result: in w
; trashes gry_in contents during conversion
; uses: gry_in,temp
; ie 2 ram locations
;================================

bin2Gry
    movwf gry_in  ;
    movwf temp
    bcf STATUS,C
    rrf temp
    movf temp,w
    xorwf gry_in,w
;==end bin2gry===================



   ;setup for reverse conversion
   movwf gry_in
   nop ; place to set break point



;================================
; Gray Code to binary routine
; entry: with grey code in: gry_in
; exit with binary result:  in bin_out
; trashes gry_in contents during conversion
; uses: gry_in,bin_out,count,temp
; ie 4 ram locations
;================================

gry2bin
    movlw 0x08    ;set counter
    movwf count   
    clrf  temp
    clrf  bin_out
g_loop
    movf gry_in,w ; get gray code in w
    xorwf temp    ; xor msb w/ 0
    rlf temp,w    ; rotate into carry
    rlf bin_out   ; carry rot's into bin_out
    rlf gry_in    ; shift gry_in for next bit
    decfsz count  ; chk if 8 bits done
    goto g_loop   ; else gloop
;==end gry2bin===================


    nop ; place to set break point


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

    end     ; directive 'end of program'

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