Something weirder - this is… I guess for lack of a better term, a “vape controller” I pulled out of a disposable vape. Reportedly some of these are actually microphones, so I was curious to find out how this one worked.
Plugged this into a breadboard, gave the red and black wires 3.3V, and it blinks its white LED once on power-up.
I shoved it into the end of a straw and wired an LED to what I assumed was the switched output. I had assumed this output would be active low, as N-channel MOSFETs are cheap and common. But it turned out to actually pull up to the positive input.
It is indeed just a pressure sensor, though. No amount of shouting or noise would activate it, it needed suction. And it does exactly what you’d expect. As long as there is sufficient pressure, the output (which would normally be wired to a heating coil) is turned on. There doesn’t seem to be a limit either. It stays on as long as there’s negative pressure.
The white LED has a neat fade to it, I guess meant to mimic the fade of a cigarette.
@bytex64 that sure looks like an electret
@petrillic It does! But I’m pretty sure it’s not for reasons I’ll explain in a moment.
I’m not sure what else this could be useful for. It’s probably not designed to sense a pressure differential at higher absolute pressures and there’s no way to adjust it. Maybe as an altitude switch for a homemade high altitude balloon-borne probe?
Sep 21, 2026, 7:52 AM@bytex64 suck/blow input device for when you have to program your computer using your mouth (loss of limb use).