> Another thing I tried was the piezo to the base of an NPN
> transistor, which grounded the base of a PNP transistor
> which passed a voltage out the emitter.  This worked fine
> with an LED and the multimeter, but didn't work well for the
> PIC ADC

If it can drive an LED there must be something missing from the
PIC setup. It should have worked with just the NPN and a pullup

How about this, for an F877 ?

http://tomscarff.tripod.com/8way_drm2/8way_drm2_2.htm

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