"M. Adam Davis" wrote:

> Another option you may have is that on some PICs the A/D converter has a Vref.
> Once you find the expected voltage level (say, 0-2.7v) you can input 2.7v into
> Vref+ and 2.7v will read full scale on the A/D.  This will also eliminate the
> noise an opamp would introduce.

How low (Voltage) can you set Vref. to?

>
> -Adam

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