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.

Not so easy — at least until now. Trill is a family of capacitive touch sensors you can add to your projects as a linear slider, a square touchpad, or by creating your own touch surface.

The board, ‘NuMaker-UNO-M4’ has the Arduino Uno pin-out plus extra interfaces, but the processor is a 3.3V device unlike the 5V processors on Arduino Unos. Communication interfaces include Ethernet, ...