There’s a lot of cool stuff brewing on the Hackaday forums. [igor_b] posted a project he’s been working on that uses a servo, motor, wine glass, and a balloon to create a one-glass armonica.
A glass harmonica is a series of nested bowls turned on a spindle that is played by running your finger along the rims of the glasses. They’re very unique sounding instruments and something [igor] decided to emulate using only one glass.
Because the note produced from a wine glass varies with the volume of liquid, [igor]‘s first thought was to use a pump to change the level of the water. He discarded this idea when he realized he could displace water by tying a balloon to a servo.
The rest of the build is a simple 555-based motor driver, a phone app written with GoOSC, and a Teensy dev board. To change the pitch of his instrument, [igor]‘s phone sends a command via WiFi to his computer, which in turn controls the Teensy, servo, and ultimately the level of water in the glass.
It’s a very cool build, but there is a small change in timbre as the water balloon displaces more liquid in the glass. [igor] tried a few other objects – a peach and a plum – but using a balloon filled with water produced the clearest tone.
Now to make a few more of these and connect them to a MIDI keyboard…