Last week I recieved the Arduino Ethernet Shield – http://www.arduino.cc/en/Main/ArduinoEthernetShield
There were all ready complete examples provided, so it was very easy to get started.
Then I thought it would be nice to have a Ethernet DMX Controller, so i could type the IP-Adress of the Ethernet Shield in explorer, and from there control my movinghead (Stairville MV250H).
Then I found this page showing how to use an MAX485 and the Arduino as a DMX interface – http://iad.projects.zhdk.ch/physicalcomputing/hardware/arduino/dmx-shield-fur-arduino/
I tried it, and it worked – And the Arduino could communicate with my movinghead.
Then I combined the Ethernet example and the DMX example, to make a HTML Page where i could click on different buttons to change the DMX values that would be sent to my movinghead.
Try it out yourself… You need a MAX485, follow the link above on how to connect it to the Arduino. Just use pin 3 instead of pin 11, as the Ethernet shield uses Pin 9 to 13!