I have no way to program bunch of PICs (i have to make pic programmer yet) but i have mighty atmega-based Teensy board. So i give it a try. Half an hour and IT WORKED.
The only external parts used are a piece of enameled wire and breadboard.
Here is the code:
ADC-Touch.py is a python script which controls teensy via usb and draws touch sensing data in graphical form on pc.
picfavr.s is a gnu assembler code for my usb interface to avr capable of reading byte from memory and writing byte to memory. Python script sends commands to it. This way i make it easy to experiment without wasting flash cycles.
cli.c is a linux-only (sorry) program which python uses to actually send commands to teensy.
If you are interested how to do that without all my mess with C just read ADC-Touch.py it's pretty straightforward what's going on on atmega side.
AN1298: http://www.microchip.com/stellent/idcpl ... e=en545264