DMX-512 module in development2010/05/04
In response to a question on answers.hackaday (this one) about an open-source DMX-512 platform, I figured I’d post something about what I’ve got under development as part of a larger project. The long-term goal is to develop a wall-mounted control panel (e.g. in the standard light-switch box) for lighting scenes. A number of these would be installed at key places in our church sanctuary, allowing the DMX-controlled lights to be operated without having to trudge upstairs and find the light board.
The module in question would be the brains of such a beast, having a microcontroller and the necessary DMX interfacing. An ATXmega would form the core, given that it’s the most versatile MCU I’ve used so far. DMX interfacing uses a pair of MAX13430’s, which are dual-voltage transceivers allowing me to run the DMX ports at the proper 5V yet interface cleanly to the ATXmega running at 3.3V. A soft-USB port is present for configuration, though that depends on either porting or rewriting the AVR-USB stack to run at 32MHz, or just running the whole module at say 20MHz (the max current speed for AVR-USB).
The module takes the physical form of a 40-pin 600mil DIP, for which sockets are easily available anywhere and everywhere. All the pins not used by the DMX interfaces are brought out on pins for use by whatever you want to drop this thing into. DMX and power connections are made via screw terminals, which could be routed to standard 5-pin DMX connectors on whatever chassis you have.
This module is still under development, as in I was modifying and cleaning up the PCB just a few minutes ago. The DIP power pins are yet to be routed, and there’s more cleanup to be done. However, I’m waiting to turn the actual boards until I get my baseline Xmega adapters populated and can start developing some of the software so I know I’m not smoking something. I expect to turn these boards in 2-3mo, and shortly make them available for purchase.