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Posted by surprisetalk 1 day ago

Audio Reactive LED Strips Are Diabolically Hard(scottlawsonbc.com)
168 points | 53 commentspage 3
askl 10 hours ago|
Interesting. I'm currently in the process of building something with a audio reactive LED strip but didn't come across this project yet. The WLED [1] ESP32 firmware seems to be able to do something similar or potentially more though.

[1] https://kno.wled.ge/

Edit: Oh wait, that project needs a PC or Raspberry PI for audio processing. WLED does everything on the ESP32.

turbine401 10 hours ago||
Check out the MoonModules fork/variant of WLED too, it has much better audio reactive user mods and visualisation options https://mm.kno.wled.ge/ than the main project.

And yea, I agree with the article. In my past I've also dabbled in audioreactive for LEDs and it's fiendishly difficult to make anything interesting.

Make it react too much, and it's chaos, and inversely when the algorithm reacts less the audio, it's boring.

And in all cases it's really not easy to see what the leds are doing in correspondence to all the complexity of music.

stavros 10 hours ago|||
Yeah WLED does it fine, I've built a few and it works well.
MrBuddyCasino 8 hours ago||
WLED is decent but tbh the lag is very noticeable. Did you compare to this python thing?
askl 7 hours ago||
No, haven't tried it.

For my use case I want something fully portable and battery powered anyways. So the audio stuff should happen on the ESP32. (Or on my phone, that might work too)

tensor 4 hours ago|||
It's pretty easy to run a pi on a battery.
ssl-3 3 hours ago|||
Eh, it's probably OK either way. People have been saying since day 1 that Raspberry Pis are not low-power devices and they're probably right.

Everything is relative, though. In terms of maximums, a Pi 4 (for example) can use up to about 7 Watts under load by itself, which adds up fast when operating on batteries.

But a single 1 meter string of 144 WS2812B LEDs can suck down up to around 43 Watts, and 43 is a lot more than 7. :)

Lighting rigs are thirsty. The processing (even if it's the whole Pi) is generally a small drop in the bucket.

mockbolt 8 hours ago||
[flagged]
isoprophlex 8 hours ago|
Are you using multiple accounts to post the same comment?!
kbouck 8 hours ago||
[flagged]
m3kw9 8 hours ago|
how is it hard, do a A to D, add a filter, do compute, then do D to A.
kennywinker 8 hours ago||
Not hard to do, hard to do well. Hiding all complexity with a hand wavey “do compute” doesn’t make that bit easy
m3kw9 7 hours ago||
Yeah i get it, the details are hard.
cogman10 8 hours ago||
The article covers that.

In short, audio and visual perception do not map perfectly. Humans don't have a linear perception of either so a perfect A to D then D to A conversion yields unsatisfying results.