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Wednesday, May 9, 2012

Video Beats - Make your own Hardware-based music visualizer!

Written by Nicholas McClanahan

Tuesday, 08 May 2012 11:13

Make your own Hardware-based music visualizer!

Video Beats is a music visualizer - it uses a microcontroller to read audio input and generate a visualization, and it displays it on any standard TV set. Here's a little demo (skip to 27 seconds to see the visualization);

The principle of using an analog signal to change a video display can be used for all kinds of projects, too - I'll give you some ideas on how to customize it in this tutorial.

What You'll Need;

Your favorite Propeller board or breadboard (I'm using Quickstart w/Quick Proto).
Two 100k resistors (Available at Radio Shack, Fry's, or online).
A copy of the Propeller Tool, and
The sourcecode.

I built Video Beats because I saw a similar project in Make Magazine and thought I could improve on the concept. It was also a fun exercise in converting analog signals into digital values. Continue to the next step and I'll answer a few questions, then I'll show you how to make your own!

FAQ

How's it Work?
Video Beats uses a Propeller QuickStart board and a Quick Proto to sample line-level audio (like from your MP3 player) and generate video graphics. As the audio input changes, new graphics are generated to match the audio. Video is output in composite, a.k.a., the yellow RCA jack.

Seven visualizations are built-in, they will change automatically, or you can switch them manually by using the buttons on the QuickStart. You can also customize the visualizations to change colors or shapes.

How long do the batteries last?
A really long time, I'd estimate about 30 hours on 3x AA batteries. You could also power it with a USB cell phone charger or a regular Wall-wart style power adapter.

Looks great, can I use it to do <<Something_else>>?
Of course! Everything is open source, you can download the sourcecode and modify to your heart's content.

Assembly

To make Video Beats, here's your shopping list;

1x QuickStart and 1x Quick Proto
2x 100k ohm resistors (source)

First, start by assembling the Quick Proto, assembly instructions are here. A few small changes to the assembly are required to make our visualizer;

Bridge C2 - this will allow us to use the Audio RCA jack as an input.
Jumper R8, as shown in the photo, to go to a 100k resistor. The other end of that resistor will go to P24.
Connect P24 to P25 through the second 100k resistor.

Here's a video walkthrough of the assembly;

Read more and see more Videos...
http://www.gadgetgangster.com/news/46-builder-news/539-video-beats.html

I like the idea of building an inexpensive device that can change a Video Display with Music. Good one's for Pro Light Shows for Concerts, use to be very expensive, back when I mixed Sound for Concerts in the 90's. I would definitely want something better looking (to me) that the Demo Shapes and Colors though. What about using the music notes to make, Fractals or mixing and blending another Video in over the original? I have to admit, that I have now idea how hard this would be to program (I'm not a Coder) or how much hardware power it wold require. But, I do know that I used a little Video Switcher, back in the 90's. That could do allot types and shapes of Video Overlay and Switching Transitions, than see here. And it couldn't have had any more CPU Power than these new Proto-Boards. I wonder if Processing could be used to make the Fractals? Processing is an open source programming language and environment for people who want to create images, animations, and interactions. I figured out how to edit and merge a couple of the example apps. It was easy enough for me, with my limited knowledge of editing Linux Config files. Well, that and I did just take an Online Class on Programming in Python (which I didn't finish, it went to fast for me). But, it did help me to know just enough to be able to edit my own Processing App (http://bishopco.homeip.net/applet/). It basically produces a Fractal animation image. I bet that if Processing would run on the Hardware. That it could be used to automatically change the Video Overlay Image with the changes in the Music.

There's a cool Fractal making App called, Gnofract. Gnofract 4D is a free, open source program which allows anyone to create beautiful images called fractals. The images are automatically created by the computer based on mathematical principles. These include the Mandelbrot and Julia sets and many more. You don't need to do any math: you can explore a universe of images just using a mouse. It runs on Unix-based systems such as Linux and FreeBSD and can also be run on Mac OS X.

Here's something like, what I was thinking about, with the Video Overlay idea...

Chroma running

Chroma is done! I got it mounted in a frame over the Christmas break, and it's working rather well. It will probably still need some more tweaks and debugging for a little while, but it's starting to work pretty reliably. I plan to hang it up at work so people can admire my work. :)

More pictures and videos of the project.

Don