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.

Instead of using mechanical paddles, [Sebastian] brought his iambic key into the 21st century by using a touch sensor. An ATtiny45 measures the time it takes for a single metal plate to fully charge.

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 ...