Instructables
Picture of LED Cube Spectrum Analyzer
In this project we’ll create a small add-on PCB containing the a MSGEQ7 spectrum analyzer circuit and show how it can drive the RGB LED cube kit from Freetronics. This allows the cube to display the seven bands over four horizontal planes.

There is a small amount of assumed knowledge for this project - To save repeating myself, please familiarise yourself with the MSGEQ7 spectrum analyzer IC tutorial in Chapter 48 of our Arduino tutorials. And learn more about the LED cube from our review and the product page.

The circuit
You can get the bare MSGEQ7 ICs from Sparkfun and the other usual suspects. It never hurts to have a spare one, so order two and matching IC sockets. Finally you should be able to translate a simple circuit to prototyping board.
 
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Step 1: The circuit

Picture of The circuit
MSGEQ7_pinouts.jpg
MSGEQ7_LED_cube.jpg.JPG
The LED cube already has an Arduino Leonardo-compatible built in to the main PCB, so all you need to do is build a small circuit that contains the spectrum analyzer which connects to the I/O pins on the cube PCB and also has audio input and output connections. First, consider the schematic in this step.

For the purposes of this project our spectrum analyzer will only display the results from one channel of audio – if you want stereo, you’ll need two! And note that the strobe, reset and DCOUT pins on the MSGEQ7 are labelled with the connections to the cube PCB. Furthermore the pinouts for the MSGEQ7 don’t match the physical reality, so compare them against the pinouts in the second image.

The circuit itself will be quite small and fit on a small amount of stripboard or veroboard. There is plenty of room underneath the cube to fit the circuit if so desired.

here's mine:
http://www.youtube.com/watch?v=qUHPLnYpxyQ

alcurb1 year ago
Interesting videos, but the LED action look a bit chaotic with music. For illustrations purposes, can you run a frequency sweep though it to better see how it works?
msminhas931 year ago
Thank you for introducing me to a new IC. I'll definitely try to use it.
moldypizza1 year ago
cool! Nice job.