Current electronics project- wall flood lighting

Recently, I've been looking for a some colored mood lighting for a couple of my rooms. I've thought that there has to be some kind of a LED powered programmable lighting solution, but in what I've seen, there really isn't much that is affordable on the market. There are some LED DMX lights and stuff, but nothing small or intended for the consumer. So, I've started looking into doing things myself.

Here's what I intend to get- a programmable color lighting source to do wall flooding behind my TV. It's really that simple. Since I've realized that I'm going to be either partially or totally designing my solution, I've added a few more requirements- cheap power supply, programmable color and brightness, and exstensibility (ability to add more/remote lighting modules). I really am disappointed that there aren't more solutions available!

Design details: I've about settled on a two part design. The first component would be a microcontroller on a board (control board), and lighting boards with LEDs on them. The control board will a USB port for programmability (and optionally, power), as well as ports to be used to connect multiple remote lighting boards, probably in the form of two pin headers (easy to do) or something witty like an RJ11 (people already have the hookup cables). The lighting boards will simply some LEDs, driving circuitry, power circuitry, and the two wire control interface. I'm currently envisioning each lighting board only having one color of LED on it.

LED selection and driver selection have been the main focuses so far, since they are by far the most difficult elements. I thought for a while that I was just going to get one of each of the brightest affordable LEDs I could find- OSRAM W5 series, 1.4A apiece, but they were a bit expensive and require quite large current drivers. I bought a TI evaluation board that has three W5SMs (350ma, RGB SMT) on it with a microcontroller. The board is actually an eval board for a power regulator (TPS62260), but I'm finding that the current regulators, despite being very efficient (96%?) buck regulators, they are more than is needed cost-wise. I've basically settled on Allegro LED driver ICs for now.

The LEDs have really been the harder thing to narrow down. I'm down to two options:

* Kingbright Superflux. These are the ones that Garrett uses for the ShiftBrite. They are 7000mcd (7kmcd? 7cd?), 20ma with RGB all in one package and Zeners for each one so you can feed them excess voltage if necessary. He is using an Allegro chip with built in PWM, which is nice on the processing end (you don't have to program PWM..), but means that it requires a bit more sophisticated interface (for the shift register). I would probably use a similar chip, maybe without built in PWM. If i went with this option, i would need a bunch of LEDs per board, as they can't be near as bright as option two. These are available for under 50c per.

* OSRAM W5SM/SN. This is what the TI eval board has, and what I suspect that I will end up with. They have a lot higher current draw, and have heat dissipation challeneges, but are a bit simpler. They are really bright, and a bit more expensive at around $3-5 per 1. I would have the capability of putting several of these on each light board.

I've got some of the OSRAM parts on the TI board, and I ordered a couple of Shiftbrites to evaluate that part. I'm anticipating making a bunch of boards for this project, and selling a good deal of them to try to finance the manufacture of the project.

Software details: 

* LED boards: none.

* Controller board: microcontroller firmware. Interfaces with a PC (optionally connected) via FTDI USB interface chip. Provides dimming functionality to connected boards. On startup, it cycles through RGB colors on all connected boards. Allows for other firmwares to be loaded via JTAG.

* Computer: I will probably write a demo application that will allow a user to set the color of LEDS and such so that the full functionality is available to people that don't have the ability or know-how to program the microcontroller. I'll likely post the project up on Gamedev.net just in case anybody there is interested in buying one/developing software.

Microcontroller details:

I haven't picked one yet, but it will probably be a PIC, ATmega, or a MSP with built in PWM, an ADC or two (for more functionality that I haven't described :D), and small size/power requirements.

Feel free to comment on the design- I haven't bought parts yet! I hope to update on the LED selection once the ShiftBrites get here, and maybe post up comparison pictures.