> ;------------------------- READ IN ANALOGUE SIGNALS ROUTINE
> -------------------
> ; THIS ROUTINE READS IN THE  ANALOGUE VOLTAGES,
>
> Read_analouge                   ; ENTER WITH CHANNEL NUMBBER 0-4 IN W
>         CLRC                    ; CLEAR CARRY BEFORE COMMENCING
>         ANDLW   B'00000111'     ; ENSURE NO ERRORS
>         MOVWF   GP1             ; TEMP STORE
>         RLF     GP1,F
>         RLF     GP1,F
>         RLF     GP1,W           ; SPIN TO PUT THE CHANELS IN THE RIGHT
> PLACE
>         ADDLW   B'11000001'     ; SET ADCON0 TO CONVERSION TIME 0F RC
> 2-6us
>         Gie_off                 ; disable int's
>         MOVWF   ADCON0          ; DO IT
>         BCF     PIR1,ADIF       ; clear intrupt flag
>         MOVLW   .23             ; 69 us wait for channel sel to register
>         CALL    SHORT           ; SETTLING DELAY FOR A/D
>         BSF     ADCON0,2        ; START THE CONVERSION
>         btfsc   ADCON0,2        ; test for finished
>         goto    $-1             ; no then retest
>         Gie_on                  ; enable int's
>         RETLW   0               ; EXIT
>
>
>
> Try this it works enter with rreqd channel in w exit with result in
> adres h,l

Why do you need to disable interrupts around the acquisition and
conversion?  A longer acquisition time does no harm, and the converted
value stays around after a conversion until you start another one.
Generally I don't like doing "long" things with interrupts disabled.

This routine requires the direct register bank to be set to 0, although
there is no mention of that requirement.  A better strategy is probably to
allow any bank on entry and set it as required.

As an aside, I've found it useful to read the A/D often based on an
interrupt.  There can be a separate interrupt for starting a conversion
and getting the result.  I usually switch to the next channel as soon as
the conversion for the previous channel is complete.  This background A/D
reading code can perform a little optional filtering on the values, then
update a software value that is always kept live.  When the foreground
code needs the current A/D value, it just reads it immediately from the
live software value.  Note that interrupts must be disabled around this
read if it is more than one byte in size.


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