Capacitive touch switches work by sensing the capacitance you add to a circuit when touched. If the circuit is an RC oscillator you can see that its frequency changes quite a lot and so the circuit can sense when a metal part is touched or not.
While building my last hexapod robot i thought it would be nice to make it sensible to human interactions, so i designed this. I think i will make a small RC oscillator and monitor its frequency with the onboard stm32f103vet6.
-nik
