Trying to build a frequency-sensitive LED milk crate wall in lieu of a drummer.

Hi all, this is my first time on this forum, any help would be MASSIVELY appreciated. I play in a live music duo https://soundcloud.com/venom-elite and currently gig without a drummer as we prefer electronic drum tones and the ability to throw in samples without the hassle of activation pads etc.

The only problem is, the energy of the live set suffers due to the absence of a live drummer. I've become kinda obsessed lately with the idea of building a wall out of 16 milk crates and filling each crate with a sheet of LED lights. These lights would then be fed to a laptop which breaks our drum track down into low, medium and high frequencies. These frequencies would then trigger different LED-rigged milk crates to create an energetic wall of light that syncs to the music.

In it's most basic form, the lower row of crates would represent the kick drum/floor toms/low frequency samples, medium row would be the snare/high toms/mid-range samples and the top row cymbals/high frequency samples. I'd be so freaking grateful for any help or suggestions on how I might go about building this thing. I've already started nicking milk crates from the local grocery store. :sweat_smile:

I've drawn up a crude diagram here - http://i.imgur.com/9XtXdbV.jpg . Thanks again for any help!

Hi,

There is a little chip, the MSGEQ7 that might come in handy for what you're wanting to do. With it you can create a 7 band spectrum analyser (use two for stereo). John Boxall at TronixStuff has thiswrite-up on the chip and how to use it with Arduino which includes software examples too. There's also a library for Arduino and if you google about you'll find there are Arduino shields using them if you don't feel comfortable or have the time to build yourself a circuit from scratch.

All the best with your project, Geoff

The only problem is, the energy of the live set suffers due to the absence of a live drummer.

Yes, let’s hear it for live drummers!

I came across this the other day. It seems to be exactly what you want to do:-

And this: http://learn.adafruit.com/piccolo/overview - if you rework the LED array driver then the FFT part could be useful.

For this sort of music visualization FFTs and DCTs aren't great as they split the spectrum up linearly - you really want to pick out each note or octave which takes something a bit more sophisticated (probably beyond an Arduino alone, laptop or RaspPi needed perhaps).

An Arduino could easily drive LED strips via an array of MOSFETs or Darlingtons, and could for instance be controlled in real time via USB-serial connection.

Simple FFT or DCT can be done on the Uno / Mega, but don't expect 1024 point resultion or a bandwidth beyond 5kHz...

The Due is more capable and can handle full range audio at 12 bit resolution, and has a lot more pins for controlling LED channels, but is 3.3V and would need careful interfacing (voltage too low for most MOSFETs, current low too, but enough for Darlingtons)