>Does anyone have any good clues as to how to impliment touch switches? Alan, Drive a sensor pad with a square wave through a series resistor. Connect the sensor to one input of a CMOS XOR gate. Connect the other XOR input to the same square wave source through an equal resistance. The XOR output is a series of narrow spikes that get wider due to capacitive loading when you touch (or come near) the sensor. Adjust frequency and R values for best results. If the sensor is remote, add balancing capacitance at the second XOR input to minimize pulse width when the sensor is unloaded. You could integrate this signal with a simple R/C network and, if necessary, use a comparator to insure perfect logic output. Or, you could measure pulse width with a PIC timer. The XOR gate could even be eliminated, at lower operating frequencies, if you're willing to use another PIC I/O pin and do that function in software. RF emissions are minimized because the sensor is fed through enough resistance that most high-frequency harmonics from the square wave source are removed by stray capacitance. You could do something similar using the PIC for a signal source, much like the canonical R/C measuring technique. Unfortunately, with any of these methods, the sensor can still bring destructive ESD jolts into your system. It's difficult to balance sensitivity against multi-KV insulation. You may be compelled to add protection circuitry... Mike Hardwick, for Decade Engineering -- Manufacturer of the famous BOB-II Serial Video Text Display Module! -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.