[Stephen Carey] wanted to spruce up his car with sound reactive LEDs but couldn’t quite find the right project online. Instead, he wound up assembling a custom bass reactive LED display using an ESP32.
The entirety of the build is minimal, consisting of a GY-MAX4466 electret microphone module, a KY-040 encoder for some user control and an ESP32 attached to a Neopixel strip. The only additional electronic parts are some passive resistors to limit current on the data lines and a capacitor for power line noise suppression. [Stephen] uses various enclosures from Thingiverse for the microphone, rotary encoder and ESP32 box to make sure all the modules are protected and accessible.
The magic, of course, is in the software, with the CircuitPythyon ulab library used to do the heavy lifting of creating the spectrogram and frequency filtering. [Stephen] has made the code is available on GitHub for those wanting to take a closer look.
It wasn’t very long ago that sound reactive LEDs used to be a heavy lift, requiring optimized FFT libraries or specialized components to do the spectrogram. With faster and cheaper microcontroller boards, we’re seeing many great projects, like the sensory bridge or Raspberry Pi driven LED spectrogram, that can now take spectrograms and Fourier transform calculations as basic infrastructure to build on top of them. We’re happy to see [Stephen] leverage the ESP32’s speed and various circuit Python libraries to create a very cool LED car hack.
Video after the break!
30 thoughts on “Bass Reactive LEDs For Your Car”
… because everyone needs a distracting visual light show at their feet while they’re driving.
I get everyone’s not the same, and many concentrate better with some music going than in total silence (I fit into this camp). However not sure adding a whole heap of in-sync flashing LEDs does a whole lot of good here.
I agree. If anything, the light’s aren’t even tastefully integrated into the car. I would rather use LED filaments between panels, just to add a soft glow like how some car manufacturers do it.
Yea, it’s a real shame the software and hardware shared here can’t be used anywhere else music might be found. Maybe that will be added in v1.1
Late 90’s called, they want their audio mod back.
Saw this crap everywhere in the late 90’s when people put huge subs in the trunk. In the early 2000’s people started to put them outside of the car.
“go build something”
“Not a hack”
“Lol, did this 20 years ago, useless.”
I have GOT to see the amazing projects you’re working on!
I support your attitude.
Someone had an idea for a personal project, and followed it through to completion. That’s enough for me.
It’s not like HaD doesn’t post a bunch about people recreating obsolete technology purely out of fascination.
Great work. I will build one for my home. Thanks for sharing.
Thanks. I’m also planning to add one near my home stereo. I’ll have to see if I can get WiFi enabled and integrated with MQTT for configuration and ditch the rotary encoder.
I’m thinking of some stereo setup too. Maybe sneak some strobe lights in there too… I really like this project, I can see so many uses.
You could have it mounted in plexiglass with a logo illuminating. Or plexiglass with a smoked section and a non smoked part for the logo to show.
Or maybe illuminate the lounge discreetely somehow.
Maybe even make the circuit connect into a lighbulb fitting so it can replace a bulb…. hmm…….
The “Bass Bulb”. I like it.
Why does it seem that everywhere one looks, one finds – more often than not – a greater number of negative, destructive comments?
Ever think that just maybe, Stephen Carey:
* Is a regular at car shows, where this kind of thing is seen all the time, while the car is parked?
* Participates in SPL contests and just wanted something extra to wow the crowd?
* Wants the install to be semi-permanent and/or readily serviceable without tearing the car apart?
* Typically doesn’t stare into the footwells whilst driving?
* Felt (as previously stated) that this could be applied in places other than inside a car?
* Was proud of his work and wanted to share his joy with the community?
You’re entitled to your opinion, but think before you post. This is akin to bullying and I’d like to think we’re all better than that.
What you’d like to think, and reality, are very different. I’d always like to follow the “ïf you’ve nothing nice to say, don’t say anything” rule but there’s a very fine line between a) not saying anything nasty, b) sugar coating nasty responses with feedback sandwich style platitudes and c) saying nasty things in a nice way which is very obvious also. Is positive-only feedback a good thing for a technical channel to have? Probably not. Is pointlessly pointing out all the negatives only a good thing? No, for sure not. But one sensitive person’s bullying is another’s challenge to do better. The big question is does the original author get a choice about whether they get negative feedback or not – if you’ve posted it online, probably no.
Too many people here (and generally in the comments) criticize the “why” and the premise of the hack instead of the “how”, or irrelevant things like security and legal problems on hobby personal projects made for fun and giggles.
If you are ready these replies, check on your email subscription notification routine on your web site. Looks like you have a small bug.
Thanks Chris. That should be fixed now.
It should really really be fixed now :)
Back in the 70’s I thought music-sensitive lights were cool too. At that time triac light dimmers were getting cheap, so I whipped up a 3-channel dimmer with audio bandpass filters for red (bass), green (midrange) and blue (treble). Worked great. Nary a microcontroller in sight. No LEDs either — it was all incandescents and theater gels (I worked as a theater lighting tech at the time).
I will never forget the acrid stink of a burning gel sheet. Turns out you can’t just throw any old piece of transparent colored plastic in front of a spot light that can heat a cup of coffee from across the room. Its been 20 years and I can still pick up that smell when I stand where that light was mounted.
That’s why you pay Lee and Rosco the big bucks.
It’s just not the same experience with the modern LED fixtures. No smoke, no 1st-degree burns, a lot less work on the catwalk (mostly no gels, for one!). Somehow they are even a lot cleaner.
Oof, memories. We had a pair of Comet follow spots (https://picclick.com/Atlas-Comet-Theatrical-Follow-Spot-light-255930872298.html). I had a real love hate relationship with those things. Burnt, shocked, small fires, stuck handles, loose shutters, melted components… but I was rarely bored or cold.
Some of us drove a precious few watts of audio into a reverse 6 volt to line voltage transformer and lit up florescent or neon lights. We had fast response light effects. Psychedelic! Not even a Triac. I’ve saw it in movies and TV at the time. The Robot in Lost in Space with it’s breastplate blinkenlights. The dialogue of a non human actor required visualization to add belief. Arm waving helps too. Danger!
I was in that camp. Also (in the car) used small audio transformers to drive the base of 2n3055 NPNs directly from the stereo. They could drive a handful of Christmas light incandescents under the dash
Bunch of gatekeeping lames here. Can’t even enjoy a hack without passing judgement on its utility.
Anyway, I wonder if the same effect can be achieved by using the microphone as a resistor with a low pass filter.
That would be simpler, more efficient, and less fun :)
Before you reinvent the wheel, have a look at WLED. There is a sound reactive version and it comes with many many other features. https://kno.wled.ge/
Thanks for the tip, I like WLED. For the sound reactive options it looks like you need a PC to handle the processing of the more interesting effects. And the small box that’s option 1 is probably just reacting to the volume. What I’ve done here is a fancier option 1 that uses software on the ESP32 to react only to the bass.
just another over engineering stuff… just use lm3915
It doesn’t look like that can react to specific frequencies like this can.
That’s the reason bandpass filters exist.
I agree a filter is a simple and efficient way to make this happen. I was interested in seeing if it could be done in software. An all software solution may have some advantages? Remotely adjusting the crossover maybe.
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