Our own Theramin!

Theramin is a musical instrument which seems to be controlled by hand movement of the user. It works on the principles of proximity sensors like hall effect sensor and the photoresistor to name a couple. To the uninformed, this device has a mystic charm about it!

All our tasks in this laboratory were built up so that we could finally make our own Theramin! Initial task of checking each sensor proved instrumental in choice of sensors for the musical device. We understood the working of each of the sensors and made a note of their capacity to produce a change in signal. After these inspection, it was decided by common consensus that we use a photoresistor and a force sensing resistance in our device. The former would control the pitch of the device while the latter provides volume control. We chose these over others as they seemed to provide the maximum range of output.

A rough circuit was built to begin with and we got on the task of writing appropriate code to control the sound of the device. Simultaneous experiments on the device provided us with immediate feedback on the code which would then be modified to incorporate stuff/music which we found missing. Final circuit was built neatly when we were satisfied with the quality of output music.

Now it was the time to work on the packaging of the device and also thinking about the human interface. A cardboard box which would be just big enough to hold Arduino board and the bread board was luckily found and we made some subtractions on it to make way for the speakers, switch and the sensors!

The design is such that the user can control the switch and the volume contol (i.e. Force sensing resistor) with one hand while the other one can be used to control the pitch of the instrument (i.e. Photoresistor).

The device was tested in the ambiance of the lab and seemed to work great! The accompanying code on the Arduino is such that it gives the user a feedback as to which note is being played and we could see the various notes by covering the light on the photoresistor. (See attached video)