AVR-Chat

--- In AVR-Chat@yahoogroups.com, "Jeff Blaine AC0C" <keepwalking188@...> wrote:

> Can you expand a bit more?
> ... Because the device did not
> seem to recognize the 4.0v bandgap
> ref, I put this in to see if varying
> the Vref would be reflected in
> different ADC readings.  It does not.  

Well, the device "not recognizing" an external reference is not the problem you've asked for help with.  You've reported that the device behaves as if it has a 5.0 volt reference whatever you configure the reference to be (correct me if I'm wrong).  If you read my post of yesterday (Message #16793), you'll see that connecting the VREF pin to a voltage source and selecting an internal reference is probably a bad thing to do.  Consult the data sheet for the device you're using.  Now that you've done that, you won't be able to rely on the device working properly as some of the magic smoke has probably come out.  In other words, you may have blown up the internal references and this could explain what you're now seeing.

Graham.