24x16 RGB LED Display - Spectrum Analyzer

Here is my most recent work, definitely the most impressive. Microprocessors are all written in Arduino and the laptop is running Processing.

This is actually three different pieces of code running on a total of 8 processors: the 'slave' code running each 8x8 LED matrices' backpack, the 'master' code running on a dedicated arduino which sends out data to the 6 backpacks, and some 'analyzer' code running on the laptop which does the playback and FFT frequency analysis which is sent to the 'master.'

This was a bear beyond belief to debug. The 'slave' code has been on a stable build for a while, so at least I had to debug on only two processors, except on two software platforms. Normally, Arduino debugging is done via printing to the serial interface, but I had to use the serial to communicate with the computer for the FFT data. Luckily Processing runs it's own 'print' box, so I mostly did server side debugging. Learned a lot more about OOP (object oriented programming) and event based code than I thought I would need, but I guess that's all for the better.

I curse modern languages (ie Processing) for no longer supporting unsigned variables. Do you have any idea how much of a headache and how much wasted time there was because my variables from PC to Arduino weren't consistent? and since when does mapping from 0 to X return negative numbers? It was mostly stuff like that that held me up.

The eagle eared (and those who've followed my other videos) will be able to figure out the purpose for my display from the music. Good Luck!

Category:

Science & Technology

Tags:

• rainbowduino
• RGB
• LED
• spectrum analyzer
• spectrum visualizer
• visualizer
• analyzer
• spectrum
• arduino

[cskiwi69]

Awesome stuff !

Is it possible to get the source code of this?

[ThreeFN]

@cskiwi69 It's largely ripped straight from the minim library FFT example code. The rest is all purpose built, and since replaced with properly written code for the rainbow and my particular setup, but basically it was just passing 16 values from the Processing sketch to the display, which the display figures out.

[chuckguy55]

Where did you get the LED matrices you're using?

[ThreeFN]

@chuckguy55 Both the actual matrices and the LED driver "backpacks" are from Seeed Studio.

[chuckguy55]

@ThreeFN Do you have a link to them on the website? I can't seem to find them. I'm trying to do a similar project and I already bought one matrix/backpack through sparkfun. I'm interested in the ones you are using however. Do they interface through SPI?

[ThreeFN]

@chuckguy55 They're called rainbowduino's (can't post links, search the Seeed depot for them). They are based on atmega168's, so they can be programmed in arduino if you have a serial/uart/FTDI board handy.

They can be interfaced through the UART or through I2C (two wire). I use that interface since it's broken out on both sides of the board for easy daising. Have a read through all my descriptions for lots of info on my setup.

[cskiwi69]

@ThreeFN

Ow, ok thanks anyway

[MattyHild]

What a fantastic project. I'm actually building something similar at the moment (albeit smaller).

[NoqturnePL]

Cool project and very fitting music :P

[ThreeFN]

@ThreeFN

Keep in mind, everything has to be 'wearable' so the fewer components I need, the smaller the enclosure can be, and the more portable everything gets. If I can do software instead of hardware, so much the better.