The theremin is just one of those instruments that nerds can't stop digging and modding. This newest iteration, the Squaremin, resembles the much-loved instrument in that you don't touch it to play it -- rather you move your hands about to control the octave and output of notes. The Squaremin was made using an ATmega168 chip, and boasts two infrared sensors to measure proximity -- one to control the note played, the other to control the octave which is played out of the front speaker of the instrument. Check out the video after the break.

[Via Make]

We see all sorts of instrument-mods around this part, but most of them are trying as hard as they might to look like regular, every day instruments. That's why the Arduinocaster is so fascinating -- it's got no interest in looking normal -- just like us! An Arduino-based MIDI instrument that makes use of switches and LEDs to control the "strings," and an opto reflective switch for strumming. Hit the read link for further details and check the video of it in action after the break.