The sensor forms an image and OpenCV detects the actual touch configuration. It appears you can use the raw data from the Arduino, too, but it might be a little harder. We imagine aluminum foil ...

The sensor shown here is essentially two plates mounted side-by-side, attached to an Arduino Nano using the Capacitor library which uses just two pins, one digital and one analog.

And the Touch Board from Bare Conductive wants you to combine your DIY spirit with the ability to turn practically any surface into a sensor. At the heart is an Arduino compatible microcontroller ...