Some more information....

after reading thru the posts.....seems to be a couple of avenues to go down.

The first is increase the setup time. Second is to add a capacitor to ground
on the pin.  Haven't tried this, as it seems to be in discussion if this is
even a correct approach.

There is two problems still...accuracy and multiple channel reads.

I changed the code to read in just a single input,and modified the setup
delay values.  I started with 255, ranged down to 10.

; xtal is 4.194 Mhz

AD_read
        movwf   ADCON0
        call    ADSetup
        bsf     ADCON0,GO       ; Start first A/D conversion
        btfsc   ADCON0,GO
        goto    $-1
        movf    ADRESH,W        ; Get A/D value and put in W reg
        return                  ; return with value in W


ADSetup
        movlw   d'5'
        movwf   DelayAD
        decfsz  DelayAD,f
        goto    $-1

I put in a breakpoint right after the call to read, and a watch window to
look at the data.

The first time thru, after being reprogrammed, from an expected value of
d'178' for a voltage of 3.5V, the value is 178 with a delay of 10, or if the
value is '255' for the delay, the first read is 186.  The second time and
all reads after that, read '187'.  The interesting thing is from a range of
1.5V up to 3.5V, the expected value vs the final stable value all have a
difference of 7 bits.  Someone mentioned the leakage current could produce
such an offset.  I can deal with an offset if I knew it was constant, but
why the initial reading be closer to the actual value and the readings after
that be stable.

So, as a result, the setup delay doesn't seem to have a large difference,
although I would expect it to actually. Is there another delay that I didnt
account for?

And this still hasn't looked at the multiple channel reads either.




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