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guitar detuner that uses accelerometer instead of microphone, it doesn't really work, but amazing to see how sensitive they are.
It also shows that it can leak all kinds of other information.
It really is crazy. Placing my phone on my chest lying down i can clearly see my heartbeat on the graph
Fun idea and also I didn't know that websites could get access to my accelerometer data. However for me the sample frequency is 50 Hz which is way too low to measure even the lowest string pitch (E2, about 82 Hz).
Anyone got a handle on the algorithm required to do this? I've got a pocketable accelerometer-enabled device I'd like to try to implement this on..
The neat bit is that it doesn't necessarily need to sample 82 Hz directly. If the sample rate is known and the target is one of a few guitar strings, the aliased peak can still be useful. The tricky part is probably rejecting the wrong alias once the vibration signal gets messy.
I mean yeah, that's cool as a fun project. And I've also heard about a project that used accelerometers as microphones for surveillance. And while it's doable, even the cheapest crappiest mic would do a much better job at recording sounds for whatever is your goal.
This sounds neat, but I think I owned a tuner for about 6 weeks before I could do it by ear... EADGBe isn't that hard.
The very clear and succinct description on the landing page makes me miss the bizarre antisocial charming quirk that people who made things like this used to be stuck with for their copy rather than AI generated language. Our cacophony of experience is quieting.
This has some very interesting privacy and security risks. If the tech can do more complex frequency analysis, then couldn't it essentially be used as a microphone for a device that doesn't need permission.
This is why grapheneos creates 'sensors' as a permission. On android all apps can spy on you this way.
My accelerometer apparently reads at 200Hz, but due to a lack of instrument at the ready I had to "pluck" the handle of the office fußball table.

When the right defender is near the center I'm reading ~24.74Hz, so slightly above G.

Cool. It worked for E and A but it failed for string 1-4. I was surprised that it worked at all.
The more reliable guitar tuners do something like this. You clip them on the neck, and they detect vibrations in the wood rather than from sound in the air.
Can an accelerometer determine when a car is having issues? Can it do the same for a human user's body?