Finally, cold cathode lights can be used for much more than illuminating the inside of your computer or making your whip look like it can hover. [James] discovered if he varied the voltage going into the inverter, only a certain amount of the tube would light up. Give a hacker an interesting observation and enough time, and eventually he’ll come up with something really cool. In this case, it’s a cold cathode audio visualizer, powered by fluorescent tubes doing unexpected things.
The build details are a little scant, but we were able to coax an imgur album of [James]’ build. He’s using these 20″ CCFL lights with the stock digital inverters replaced with TDK CCFL inverters.
The digital control of this build is provided by an Arduino Mega and a custom shield. We’re guessing the graphic EQ is provided by an MSGEQ7 chip, and the inverters themselves are powered through the Mega’s PWM pins. It’s a lot like an IN-9 Nixie graphic EQ, only much, much bigger. [James] is planning a larger version of this build, dubbed the Mega speKtrum and we can’t wait to see that build along with a proper writeup.
[Andrew] built a light box for an exhibition last year that displayed different colors statically. After showing it off, it went unchanged but future improvements remained in the back of his mind. Recently, he pulled it out again and hacked together a controller to drive the colors individually.
He’s actually reusing some of the hardware he built for a different project. At its core is a PIC 16F628 that actuates the lights using relays. In this case, only four of the eight on the board are used to control red, white, blue, and green cold cathode tubes. The video after the break shows the device randomly rotating through different patterns. This is a nice start to making the piece more interactive and we can image adding web-controlled color changes, or perhaps some Daft Punk inspired functionality.
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