Hi Dwayne again,


> You have a nice little 60 uSec delay there that does no good whatsoever
> where you have it.  Move that delay between the 'select channel RA0' and
> 'start conversion'.
>
> This is what I mean:
>
> > START           SCHRA0                  ; SELECT CHANNEL RA0
> >
> >                 MOVLF   .20,TEMP        ; THIS LINE IS 20
> >                 DECFSZ  TEMP,F          ; WAIT A WHILE
> >                 GOTO    $-1
>

if I am wrong I tried with out the delay did not work properly.
I do not know.


> >
> >                 BSF     ADCON0,GO       ; START CONVERSION
> >
> >                 BTFSC   ADCON0,GO       ; TEST FOR END OF CONVERSION
> >                 GOTO    $-1
>
> Try it!
>
> 2)  You may have a misunderstanding of how W is used.  You do the following:
>

I am not sure what do you mean?

> >>                 MOVF    ADRES,W         ; LOAD A/D RESULT INTO W
> >>                 COMF    ADRES,W         ; COMPLIMENT IT
> >>
> >>                 MOVWF   ADC_RESULT      ; STORE IT
> >>                 MOVWF   PORTB
>
> The first instruction 'movf adres,w' copies the value stored in adres into W.
>

yes

> The next instruction 'comf adres,w' takes the value stored in adres,
> compliments it, and stores the result in W.  Notice that what was in W from
> the first instruction is now overwritten by the result of the second
> instruction.

yes

>  The first instruction (movf adres,w) is not necessary.
>

     this code wasn't done when  I posted to pic list
    seeing extra instruction specially this one "above" doesn't even bother
    I do not thing you should even worry about it.

   Hope this helps.

> dwayne
>
> Dwayne Reid   <dwayner@planet.eon.net>
> Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
> (403) 489-3199 voice     (403) 487-6397 fax

  Andre