Hi!
Having used a week searching and reading, I find a lot of useful info in this forum (and others, like doityourselfchristmas), but not exactly what I'm looking for. What I want to do, as many other here, is control my lights (mood settings, etc etc). I'm planning in having each spotlight (currently 12VAC halogen spots, might move to LEDs later) on a separate channel. That way, only the imagination sets limits for how I can control the lights. For example, I can choose to only lit the lights over the desktop. You get the idea.
I want to use I2C, because of the cheap hardware available(example NXP's PCA9633). That way, I could build cheap dimmer modules, and wire them up with a bus cable. I'm planning to power the dimmer modules with the 12VAC the spots is running, a simple rectifier with 7805 will probably do the job(?). The I2C master will be a Arduino. This allows for a simple wiring in the ceiling. The 12VAC transformers are already there, I just need to wire up a bus cable between every 4 spotlights, and having connected the Arduino somewhere on the bus. I'm thinking to communicate with the Arduino over ethernet(so that it can communicate with OpenRemote). The arduino could be powered over ethernet. The lights will be controlled with PWM on the 12VAC side, using a power mosfet or a triac, allowing high power lights(PWM might be a problem for the transformer, especially when near to the minimum load specified).
This setup makes it possible for some 120 dimmer modules connected. Since PCA9633 supports 4 channels each, this will support 480+ separate controllable lights in ideal environment(bus length, etc). If the length of the bus become a problem, I could use buffers (PCA9600), shielded cable, lower bus speed..
And so, to the question. I have seen many things that looks like this (high power led shield, TLC5940 solutions, ++), but not quite this. Have this been done before?
I'll attach some sketches I quickly drew.
