[Tobie’s] part of the hack is to use an Arduino and a few buttons as the controller. It’s easy to set up and we think the breadboarded controller approximates the size and weight of an LCD ...

At the heart of the device is a AD9833 waveform generator; with the Arduino, rotary encoder, and 16×2 LCD providing an ... a X9C104P 100KOhm 8-bit digital potentiometer as a voltage divider ...