I have an interest in capacitive touch at the moment – I have no particular project in mind but I wanted to see the current state of cap-touch solutions so that I could use it in a future project.
To test it out I made a board with a single touch pixel. I can use this board in other projects as a drop in touch solution. I decided to go with Microchip’s (formerly Atmel’s) qTouch library with their Peripheral Touch Controller (PTC).
The simplest chip containing a PTC is the Atmega328PB which comes in a 32-pin TQFP. The only other components on the board are a 3.3V regulator, the programming port and the other necessary passive components.
It is nothing too complex. But it works.
Atmel offer a web tool called Atmel Start which walks through configuring the PTC and then generating a code template.