### Open Source Theremin based on the Arduino Platform
Open.Theremin is an arduino shield to build the legendary music instrument invented by Leon Theremin back in 1920. The theremin is played with two antennas, one to control the pitch and one for volume. The electronic shield with two ports to connect those antennas comprises two heterodyne oscillators to measure the distance of the hand to the antenna when playing the instrument. The resulting signal is fed into the arduino. After linearization and filtering the arduino generates the instruments sound that is then played through a high quality digital analog audio converter on the board. The characteristics of the sound can be determined by a wave table on the arduino.
For more info on the open source project and on availability of ready made shield see:
3. In "Application.cpp", take care of selecting MIDI mode that correponds to your cituation (put "//" in front off inadequate line - MIDI through serial is selected by default here):
//Serial.begin(31250); // Baudrate for real midi. Use din connection https://www.arduino.cc/en/Tutorial/Midi or HIDUINO https://github.com/ddiakopoulos/hiduino
Default configuration is: Register = Lowest Register, Timbre = 1st Waveform, Channel = MIDI Channel 1, Rod antenna mode = Legato on/Pitch Bend on, Pitch bend range = 2 Semitones, Volume trigger = 0, Rod antenna cc = None, Loop antenna cc = 7-Volume.
When legato mode is activated, if you trigger a note (with volume loop) and go in one direction (with pitch antenna) a new note will be triggered at the limit of pitch bend range.
Legato mode is used as a workaround for a limitation of midi (max 24 semitones pitch bend). Maybe some synth can perform pitch bend on more that 2 octaves but none of mine does...