Martin SchŠfer wrote:

> Hi Thomas,
>
> I have seen that the TRIS is OK, but here are some questions to you:
>
> 1.  What is your VDD doing? (VDD = 4.06V?)

VDD is 5.05 Volts with less than 5 mv noise.
(The processor stops when the A-D input voltage risies above 4.14 volts.)

> 2. Change the PIC. It may be corrupt because of an prior latchup.

I've programmed 4 new ones so far...

> 3. Wouldn't it be better to set the TRIS-Bits before you start the AD-Module? This
> might not have an effect on the solution of your problem. But better you exclude
> any doubts.

I can try this.

> 4. Let the sample time be at least 40us.

I have tried much longer times, with no improvement.

> 6. What is your Clk-Freq? At 20MHz you will have problems with 8Tosc.

It's 1 Mhz.

> 7. You enable PIE1,ADIE. Why? And why do you clear the ADIR. You dont use it.

Left overs from other things I tried...

> 8. IMHO the input filter is not so essential as it is discussed here. More
> essential is the value of the resistor, what was discussed before.

Changing the value lower did nothing either!

> I hope something is working. Point 4 is the most important!!!

--
Thomas C. Sefranek  WA1RHP
ARRL Instructor, Technical Specialist, VE Contact.
http://www.harvardrepeater.org
http://hamradio.cmcorp.com/inventory/Inventory.html