[Mike Herr] found a grey area by mechanically interfacing an Arduino with a straight key. You can see the straight key being pressed by a hobby servo in the image above. The servo is driven by the ...

At the heart of the device is a AD9833 waveform generator; with the Arduino, rotary encoder, and 16×2 LCD providing an interface to control it over SPI. Unfortunately, the AD9833 doesn’t have ...