ATEMGA168 TLC5940 PWM RGB Led Cylinder

95 pieces made ​​using RGB LEDs Led cylinder project quite professional printed circuit board, software quality circuit that is used quite ATEMGA168 microcontroller with integrated LEDs TLC5940 LED driver plowed. Installation was very difficult olmasy RGB LEDs makes the circuit very nice effect, but I made ​​certain to be very puzzling. Also prepared with eagle pcb source, schema tlc5940.lb source C library and ATmega168, given java code.

This is a little art project I made with 95 RGB LEDs arranged in a 3D cylinder sitting on a microcontroller-based driver circuit. The LEDs are individually addressable, and when you turn it on, the software cycles through a series of animations, such as various animated rainbow patterns, “rain,” “fireworks,” etc. It doesn’t really serve a purpose, but it’s pretty cool to look at. The hardware and software are open source, so feel free to use/copy/extend what you find here (subject to the CC/GPL license terms).

The LEDs are wired in a 5-way multiplexed grid. The anodes of the 19 LEDs on each plane are connected to each other. The cathodes of each LED are connected to the cathodes of the other four LEDs in the same vertical column. So the LED matrix has five anodes and 57 cathodes (19 LEDs per plane * 3 cathodes per LED). The driver circuit uses five IRLU3715PBF N channel mosfets to switch the +5 volts to the anode rails and four TLC5940NT 16 channel PWM constant current LED driver chips to switch the cathodes to ground.

Since I am using the N channel mosfets as the high side switches, I need to generate a higher gate voltage than Vdd. I use a simple charge pump to double the +5v from my power supply and drive it to the mosfet gates using three TC4427ACPAs. The mosfet drivers are in series IRL (i.e. logic level), so they are fully turned on with +5v Vgs. Rds-on is in the 15-20 milliohms range. The TLC5940s are set to sink about 20ma per channel.

Source: Dave Clausen alternative link: