DMX in light multiplexing

Projects General Guidance
1

hello.

I plan to start an arduino project to let You take inputs from potentiometers,handle the inputs and output them to one branch of 32 intelligent DMX light devices.

Before I start this,I wonder if anyone else has worked with this and if one of the Arduino uC is capable of handling such a project?

Thank You

regards

2

I've never used DMX, but if you google "Arduino DMX", you'll get some good hits. This should be no problem once you understand the DMX protocol.

There are basically 4 issues to deal with:

  1. The electrical DMX interface. You need an RS-485 driver chip.
  2. The DMX serial protocol. (I assume someone has already written a software library for this.)
  3. Your Arduino program (sketch) and it's interaction with the devices (DMX lights).
  4. Your hardware (pots, etc.) and their interaction with your software (sketch).

I'd work on these in that order... Build DMX hardware interface, and get the protocol working with a simple program that blinks the lights on & off. Then, start adding features to your program for dimming the lights, moving them if they are motorized, or whatever DMX features they have, etc... Finally, add the input-hardware to "drive" your program.

3

DVDdoug:
I've never used DMX, but if you google "Arduino DMX", you'll get some good hits. This should be no problem once you understand the DMX protocol.

There are basically 4 issues to deal with:

  1. The electrical DMX interface. You need an RS-485 driver chip.
  2. The DMX serial protocol. (I assume someone has already written a software library for this.)
  3. Your Arduino program (sketch) and it's interaction with the devices (DMX lights).
  4. Your hardware (pots, etc.) and their interaction with your software (sketch).

I'd work on these in that order... Build DMX hardware interface, and get the protocol working with a simple program that blinks the lights on & off. Then, start adding features to your program for dimming the lights, moving them if they are motorized, or whatever DMX features they have, etc... Finally, add the input-hardware to "drive" your program.

hello, thanks for answer.

The rs485 communication speed is some of my conserns regarding one arduino handling both the readings of analog outputs from control panels, perhaps handling input informations in some way and then outputting them to the dmx cable where the lights are connected.

What I currently trying to understand is how to include the device-adressing in the information sent to the lightdevices. I hope to get an understanding of that when jumping into the protocol.

regards

4

Looking at the DMX 512, shows me the sequence of bytes is assigned to the number of channels. i.e. 1st byte is for the 1st channel. Some devices uses more than 1 channel.
The protocoll seemes to be stright forward. Now Ill have to find a rs-485 transmitter. I think I only need transmitter trying out the dmx dimmer at first (?)

Anyone aware of the needment of tranceiver regarding dmx devices in general?

thanks

5

here is a link to a dmx library: Google Code Archive - Long-term storage for Google Code Project Hosting.

to convert the serial to rs485 you need a converter ic like sn75176 or max485.

you connect i like this.