LED Driver

LED Driver Prototype 1

So, what is this monster power supply going to power? LEDs, and lots of them. Some of these LEDs will always be on; some will be on under certain circumstances (e.g., on a day/night cycle); many will have special effects (e.g., traffic lights). To accomplish all of this, I have been working on a special-purpose LED driver. (It needs a name, and I’m open to suggestions.) Pictured to the left is an early prototype of this device, which combines an Atmel microcontroller with a Texas Instruments TLC5491 LED driver, lovingly hand-soldered to a breakout board. (DIP samples were unavailable, so to save money, I ordered HTSSOP samples and soldered them to an inexpensive breakout board.)

The design goals:

• Modularity: The TLC5491 supports unlimited chaining, and so too should my system. Each board will be independently powered by its own wall-wart, but indefinitely many boards can be chained together. My layout will grow over time, and so too should my lighting system.
• Fancy-Shmancy Effects: The board must be more than just a power-distribution bus. The board must be able to provide arbitrary special effects, programmed in software. My layout will include static lighting, and traffic lights, and maybe even some emergency vehicles. I have no idea what I will want in the future, and so I shouldn’t be arbitrarily limited by bad hardware decisions early on.
• Ease of Use: The board should be as simple to program as possible. I get frustrated very quickly by complex systems that are too difficult to take full advantage of.

At this point, I’ve got a nearly-finalized PCB design, just about ready to be sent off for prototyping (I’ll be using BatchPCB—slow, but so cheap!); I still need to order a few more component samples, and I have a fair amount of firmware to write. But I’m excited about what I’ll have when it’s done.

The question I have is: Is anyone else out there interested in this?