It’s a fairly simple project, too: just hook an Arduino Uno up to a motion sensor and an electronic switch called a relay, then plug in your fan, and you’re good to go.

Each one of the switches can detect pressure or vacuum, so one switch set to each is fed though a Y and up to the mouthpiece, since everything is sealed this has the advantage of only needing ...

Of course it ended up getting a bit more complicated than that, as tends to happen with these kinds of projects. For one, the sound doesn’t directly control the solid state relay used in the fan ...