TLCDrive485

Here's one of my latest litlle projects... It started from... well I had 3W RGB Leds (from DX.com), some TLC5940 and plenty of little MSP430. I thought I'd do something cool with all that stuff, and I remembered of a really cool project featured on HackADay: ACRIS. I didn't want to make something as complicated, but the main idea is the same.

I also bought some MAX485, and one USB > RS485 dongle, so the boards can be chained on long lengths without much problems. Aaaaannnnd here it is :

Well, not much to say about it. There's a python Script on the computer that manages the colors. The board hosts one MSP430G2231 (or MSP430G2211) and one TLC5940 which outputs are configured so you can draw 100 mA on 5 outputs.

Since the ┬ÁC is cheap and small, the TLC5940 management is bit-banged, and the TImerA is used for the Serial communication. I hoped I'd be able to use the Timer to drive the TLC5940 but my first tries were unsuccessfull and bitbanging works quite well =)

Serial communication is Half-Duplex (using a software UART, it's easier this way). It's not a real problem since the board acts as a slave and the RS485 communication is half-duplex with one MAX485. I tried t o keep most of the processing load on the computer so the communication protocol is pretty rough... See main.h for more infos, and open the source of the Python file to find out how to use it.

 

  

It's not perfect but it's a cool quick project (from idea to the populated board, it took me one afternoon, and two days to complete the code)  and I finally used some of those tiny MSP430s I had laying around. They're really neat, even if the ones I have are quite limited, I think the bigger ones can be really cool =)

Code, Schematics, ... can be found here: SVN TLCDrive485