alzymologist

Moomin vibes?

I’d think it’ll work even better with egg whites? That’s the microbiology cleaning trick based on the same idea or forming protein coacervates, except the eggs are pure protein so they are probably cleaner way to do it.

coconut milk is so much different from regular milk though, it’s fat (somewhat soluble in alcohol, but it still could extract liophilic stuff, if you can separate it, for example, by chilling)

just make random files with notes and then grep, the most efficient approach for crazy chaotic homelab imho lol

some day llms will be able to parse your homelab notes

Ok, I’ve done experiment myself; it was a dumb idea. Sure I can see the bass beat on smarthone hall sensor as sharp periodic spikes… from few cm away of the coil.

Thing is, any measurable signal outside of coupled system is essentially power loss, which industrial made speakers are, obviously, optimized against. The field loops back into the magnetic drive through the shortest achievable path. Then, it’s not your typical radiative EM system, it’s low frequency near field transmission - field drops exponentially as you move away from the coil.

Most probably, you’d need to measure long periodic signal, do lots of oversampling, etc. to gen anything. Or build a high fidelity resonator to steal the field from the speaker - essentially, same thing, except the resonator will probably start singing, too.

So I’d give up on magnetic approach; why go for counteroptimized signal when you have optimized acoustic field? Just analyze it - look for sustained harmonic vibrations, fat envelopes so different from human voice barking and foorsteps; EDM are full of those nice sounds.

Could be doable with just a hall sensor chip, you have one in your phone, just check it out quickly. Large coil will probably catch slow vibrations too. Also try just filtering audio signal, like get only sustained bass sound, footsteps and voice have short lived low frequency components compared to most music except for percussion I suppose.

hell yeah, I’ve made a whole useless product like that! In lab, we had OLED display powered by NFC too, and touchscreen e-ink tetris device, and spot welder lol. Nobody believed me it’s possible, even engineers who worked with me, might be I was the first one to come up with this hack.

This is a fine approach too. Just be aware that most modern mcu would be a hell to mount on DIY. Also, this works on literally any paper with super bold print setting.

I would recommend trying copper-based etch, it’s easier to work with than FeCl3 (it’s transparent, to begin with, and not as corrosive to other stuff). Edit: remember to wear goggles, all these things really destroy eyes on splash. Wash eyes for at least 15 minutes with running water if got it there.

Also, I’ve heard some dudes made really nice stencils for paste with some cheap hobby blade CNC tools on cardboard, there are models that have orders of mad higher precision than advertized. Never tried this myself though, lazer cut stainless steel plates from factory are just soooo good (and also a source of high quality steel in a workshop when you don’t need them anymore, they make perfect wood scrapers and such)

oh, and do not be afraid of surface mount. It’s actually easier than it looks, especially if you were smart and did order a stencil (otherwise it’s a toothpick and paste, nothing too hard, just… so slow that paste will dry out).

paste recommendation: ChipQuick. Surprisingly, stuff from hobby shop works better than many professional products, even in professional settings. I had my team leaving spatula on stencil printer for months, just warm it up a but and it’s like new. Magic.

Eagle is dead. KiCAD is certainly the choice, both from starting hobbyists and for high level professionals. Order you PCBs somewhere, order stencil. Buy components yourself, solder yourself, make stencil holder from cardboard. Do not mess with assembly orders unless you’ve learned how it works at home. Get a fan and soldering iron, relly good tweezers (I recommend Tweezerman not made in China, absolutely best gear even though it’s made for other purpose, works for electronics and electron microscopy sample handling).

Really weird fact: AI is useful for converting datasheets into kicad models, sometimes even 3D. Finally some dumb menial task worth of AI - format conversion. That’s that those damn things should be used for.

Altium is nonfree shittyalternative for kicad by now. Don’t. Especially for hobby.