The "Ditofono" is a simple and particular musical instrument to play with your fingers. It is a synthesizer able of generating an acoustic note reproduced by a buzzer, which can be varied tone and sound volume simply by moving two fingers in front of as many LED / photoresistor groups (and LDR2 LD1, LD2 and LDR1). Putting a finger between LD2 and LDR1 and moving it in such a way as to obscure more or less the sensitive surface of the photoresistor, we can shift the frequency and with it the hue of the generated notes. The volume control is obtained by putting the fingertip of a finger between LD1 and LDR2, according to what we obscure the photoresistor will vary the volume level.

This project comes in  kit . Some components have to be soldered to the included PCB.