> Do I have to be concerned about connecting the output of the
> op-amp directly to the PIC ?

Not really, but I'd pass the signal through a resistor (few hundred
ohms) and limit the PIC pin with a 5V1 zener, just in case. Add a
reverse-biased Schottky too, anode to 0V, cathode to PIC pin, to
catch any negative excursions. Analogue inputs are wont to frizz

The LM324 would be OK as its output can go to 0V

Microchip do have recommended impedances for the signal. I
think there are two, 2k5 and 5k. It is possible to exceed that
with a greater or less effect on the result. An opamp would be
pretty low impedance. The resistors you choose for the divider
depend on the value of the pot. If the linearity of it is affected
you might buffer the pot and have the didvider after that

Joe

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