Automatic Pneumatic Harmonica

A wise man once said “If all you’ve got is a cute desktop compressor and some solenoid valves, everything looks like a robotic harmonica.” Or maybe we’re paraphrasing. Regardless, [Fabien-Chouteau] built a pneumatic, automatic harmonica music machine.

It’s actually an offshoot of his other project, a high-speed candy sorting machine. There, he’s trying to outdo the more common color-sensor-and-servo style contraptions by using computer vision for the color detection and a number of compressed-air jets to blow the candy off of a conveyor belt into the proper bins.

But before that gets rolling, a test of the computer-controlled pneumatic setup is in order. And that’s where the harmonica entered the picture. The “build” is really just him putting the tubes from the candy sorter into a harmonica. There’s an ARM processor spinning its high-powered wheels, and some MOSFET drivers to open and close the valves. But that’s it. Watch it play a “tune” in the video below.

We love wacky instruments, robot anythings, and serendipitous spin-offs. What’s the coolest project that you’ve made that wasn’t the main project, but just a step along the way? Did you plan it in advance or did it just happen? Did you have the guts to post it like [Fabien]? Can we encourage you?

17 thoughts on “Automatic Pneumatic Harmonica

  1. lol k…

    i had an idea for something like this,… but with a slide whistle… a servo controlling the whistle length and air pressure to the whistle with a solenoid valve

    had it working with tests but no air compressor,.. maybe i’ll try again

    1. I might go with something like a hard drive voice coil rather than a gearmotor servo. It should be able to produce a much smoother transition with less added noise to the result. Maybe a spring loaded solenoid would work, just use driver with controllable current and you should be able to position it.

      1. That is a brilliant idea with the hard drive voice coil! I think it would work quite well attached to a plunger or syringe with a spring added to bring the actuator back on its own. A little less gaudy than the air compressor lol. I could imagine a calliope / organ could be also made in a similar manner.

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