> Yup, you can read multiple keys, but you can't quite do it in the manner
> Mike is suggesting. Mike is close, but has to change his resistor
> ladder to R, 2R, 4R.... to catch multiple keypresses and I wouldn't
> recommend going more than 5 buttons on a plain PIC pin (using the
> method kRC = T), or 7 buttons on an analog input since by the 7th
> button you're at 64R (getting close to 1% tolerance values) .


How about just going R, 2R like an R-2R D/A? It's simplest if your
switches are SPDT and switching between +5 and ground. You could use
resistor networks where the matching between resistors is much better than
the absolute tolernance.

Harold


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