On Wed, 29 Mar 2000, Dan Michaels wrote:

> Scott wrote:
> >
> >First, here's Tom's circuit (modified somewhat)
> >
> >                     O +5v
> >                     |
> >                     |
> >                     \
> >                     / 10k
> >              1uf    \
> >                     /
> >               ||    |
> >AC Input >-----||----*-------> To Pic I/O
> >               ||    |
> >                     |
> >                     \
> >                     / 3.3k or 4.7k
> >                     \
> >                     /
> >                     |
> >                     |
> >                     O Ground
> >
>
> In this ckt, you might also want a 10K resistor from the
> junction point to the PIC - for overvoltage protection. It
> shouldn't otherwise adversely affect operation, due to hi-Z
> into the pin.
>
> Also, what is your or anyone else's opinion about connecting
> an analog voltage at a digital pin, viz-a-viz positioning
> the input voltage into the "no man's" range of operation
> of the gate?
>

It causes the pic to consume more current - otherwise it's no problem.

Scott