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.
Careful planning and a steady hand let [Leo Rampen] fit everything he needed to build a graphic equalizer display on his LED wall sign. There’s a lot of components that needed to fit on this board, and he decided not use to an etched board for the build.
The idea for the project started off as just an LED sign. After spelling out “Sweat Box” using LED rope lights, he needed a way to switch them on and off. But why stop there? He also decided to use an MSGEQ7 chip in the build since the sign adorns their party-room and adding music-based flashing lights seemed like a good idea.
He laid out the equalizer chip, ATmega328 (running the Arduino bootloader) and a series of N-channel MOSFETS for switching the LEDS out in Eagle. With design in hand he grabbed a medium-sized piece of strip board and used a drill to cut the traces where necessary. In the end he has a very flashy sign as shown in the clip after the break.
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