another way to get a keyboard matrix to work off 1 adc pin

[wdmagic]

Another way to run the keypad might be to use a series of capacitors instead of resistors, and have the oputput tied to a 555 timer with fixed resistors so that the kaypad actually changes the frequency which could be a large range and output to the PIC, then instead of using the ADC IN, use PULSE IN, so that instead of counting milivolts from a adc, you could count a large range of pulses.
Just an idea.

Add On: not sure if it would work though, might have to ad a cap in parallel with entire pad since the 555 would need a cap even if the keys are being pressed