> Solutions:
>
> - Reverse biased Schottky diodes to either supply from pin.
> - 2 resistors in series for input resistor with 1N4148 type diodes at mid
> point of resistors to supply and ground (back biased usually).
> - More complex systems.

What about R, 4.7 V Zener to ground, R from zener to PIC pin, R from pic
pin to +5?