DMX controlling more than one RGB LED

Forum 2005-2010 (read only) General Frequently-Asked Questions
1

Hi,

I am quite new here and with the Arduino.

Currently I'm experimenting with DMX protocol on controlling the sequences of lights.

As to date, most of my search on Google I found out to only control 1 RGB led.

my questions are:

  1. is it possible for the Arduino to read/write the DMX address with the Arduino?
    what DMX chip is compatible with the arduino and how can I do
    this?

  2. is it possible for me to control more than one RGB LED using the
    DMX protocol with the Arduino? Let say, 6 RGB LED connected in a row (daisy
    chained).

As, I've only seen lots of examples that control only 1 RGB (e.g:simpleDMX ). How can I daisy chain, and program/set address?
Can anyone show how to do this?

Sorry if the question sounds too simple, thank you for the helps.
If possible, please provide any good links/ or reading materials so that I can go through.

2

The DMX protocol can support many channels. The simple way would be to just use more channels. However you could use the data passed over a single channel to control more than one LED, just look at the single RGB code (that is actually 3 LEDs) and extend it. So you might add an extra number in the DMX message that specifies the LED number. It is a simple matter of modifying the code inside the arduino to cope with this.

3

Thank you for the explanation.

I think, the programming part, is OK. As the explanation on the DMX simple regarding how to control the LED is quite detail.

But, how can I program/set/write the address on the DMX?
As what I've gone through, most of the codes are for controlling the channels, and not read/write the channel. If I've missed something here, please let me know.

How about the circuit?
Is it by using the Simple DMX circuit or the one made by the tinker.it and extend it by two, three and so on?

Thank you.

4

Have you read this:-
http://www.arduino.cc/playground/Learning/DMX
I think it addresses most questions.

But, how can I program/set/write the address on the DMX?

I am not sure what you mean. The DMX master sends out the address on the common bus. The DMX slave listens to the bus and only responds to it's own address. Therefore in the master is some number that it uses to compare with the received address to see if it is being addressed. You need to find this number in the slave software and change it.