***Updated on May 24th 2012***
A fun project to build a theremin with an Arduino-based system. My ultimate goal is to build it into a standalone PCB with an independent ATMega at the control. The source code is stored in the arduino-source directory and schematics are in the Eagle file format in the schematics directory.
After some work, I have found the original 4.11 MHz schematic to be sound but the source code had a lot of room for improvement. I am working on updates and they will be posted soon.
The original Arduino source code and oscillator schematics are based on:
Additionally, I am looking at using a low-pass filter and DDS technique based on: