14 January 2012

DMX Spot project

The aim of this project is to build a small PCB board for RGB LED installations and to use the DMX protocol for controlling.

I build this board because I want to have a permanent and robust solution for light installations and I like to release my Arduino board for other projects.

Also, when using a standard Arduino board there are many components built in that are not used at all. For a simple DMX solution the ATMEGA 168 that was used in older Arduino versions is powerful enough and still provides enough memory for complex programs. So all you can find on this board are the minimum components for a 3 channel DMX receiver and the components to drive LEDs with a voltage around 12 volts or higher.

Because I started with an Arduino board many characteristics of the Arduino design remain:

  • The processor can be a Atmel ATMEGA168 or ATMEGA328.
  • The clock speed is 16 MHz.
  • The surrounding elements like the capacitors have the same values.
  • The software implementation uses the Arduino environment.
  • I can reuse all the source code I have written so far for my Arduino.

The additional parts compared to the Arduino board are the chips of the communication interface that is able to receive DMX signals including an isolation and 3 Mosfet chips for driving LEDs.

The board uses only standard through-hole soldering components allowing an easy building for hobbyists like me.

Here are some pictures of the Arduino assembly and from my first prototype.

There where several problems with the first version so I had to patch some wires and add some components on the back. Not good enough to be published.