Circuit Lake

Electronic Project and Circuit Collection

DIY Mini IR Theremin

07/08/2011 Category: Audio, Miscellaneous, PIC, Project

The purpose of this project is to build a simple Theremin that can play the base notes (no sharps or flats) from one octave to another, specifically C4 to C5. Instead of using antennas, it uses infrared proximity to sense the position. The device will produce a specific pitch after IR proximity sensor detects the distance between your hand or an object from it. The project uses PIC 18F452 as main processor and Sharp 2Y0A21 or GP2D120 IR Package for the sensor.

How to build theremin using microcontroller

Chris, the project designer, said that PIC’s internal Analog-to-Digital converter will be in charge of translating the IR proximity sensor feedback data which the PIC will translate into a usable distance number. A fast timer interrupt circuit will be created inside the PIC to constantly be playing the tone for the last distance detected. If nothing is within the ‘playing field’ of this IR Theremin, no note should be played.

IR Theremin
Project Firmware, Schematic and Documentation