Currently, I am using the PIC16F72x series that have a built in Capacitive Sensing Module (CSM) that are designed for touch sensor applications. These chips work great. You don't need any tunning and they are 100% reliable.

The reason I first tryed Mister_E's circuit with a 16F84 is because that's one chip that I had handy at that moment. I could see a small change in voltage amplitude at the input ports when the sensors were touched, but they weren't reliable enough in the circuit I built. Maybe I needed to do some adjustments and tunning. Any ways, I think it's a great idea Mister E came out with.

I just love it to see all the smart a** comments you can find in here that do not contribute to resolve any issues and that do not provide any technical guidance at all.

Robert