The Open.Theremin is a modular theremin system. There are three modules, the Open.Theremin.RC, the Open.Theremin.LC and the Open.Theremin.UP. The modules RC and LC are discrete, digital theremin circuits. The two modules are very similar. The RC module uses a resistor-capacitor resonator for the hand sensitive resonator. The LC module uses a coil-capacitor resonator. Both modules can be used and tested as simple standalone (pitch only) theremins.
The Open.Theremin.UP module consists of a micro-controller, interface and supply circuits. It can be combined with either one or two LC or RC modules to form a much more performant and versatile theremin with pitch and volume control as well as improved antenna characteristics. In the micro-controller the antenna signals of the two connected theremin modules can be read and process independently to implement advanced features like curve correction, digital filtering, control voltage output and waveform generation.