Multichannel Touch Sensors

A versatile, modular and scalable multi-channel touch sensor system is demonstrated. The touch sensors are constructed using the Qprox QT1103 10 channel capacitive touch sensor IC. A working 100 channel touch sensitive keyboard using five of the sensor boards is detailed. Device integration is enabled using a dsPIC (dsPIC33FJ128GP706) controller board. A stand alone 20 channel device incorporating Bluetooth wireless communications is also demonstrated. This incorporates a LM3658B battery management IC circuit with a rechargeable lithium battery. Correct device operation is verified using a novel port expander arrangement based on the MCP23S17 port expander IC