DMX Interface - Anyone build one?

[mliptack]

So this isn't for anything laser related... but rather for LED control.

I have a project that I am working on that requires me to control an RGB LED with DMX protocol.

I have NEVER built any DMX interface before and I need to figure out where to start.

Here are my requirements:
I need to control an RGB LED Strip (I believe they run at 12v per Color Channel).
So I need to build a controller card which will take DMX from a lighting console and dim the particular control channel.

The interface will be 3 channels set via a dipswitch. The DMX must also have a passthru to continue the data link to other lights or other equipment.

Do you guys have any ideas where to start? I started searching for DMX forums, but I figured, why not start here where I know there are some people who have done stuff like this before.

Any help would be greatly appreciated.

Thanks everyone,
Max

[flecom]

http://cgi.ebay.com/DMX-512-Common-C...item53df1bd8e2

[Pitts]

Hi Max

Also worth checking out Dave here on PL.. (LaserShowparts - Australia) he makes up DMX relay boards.
See their website..

Cheers
Ray
NZ

[FLoWLASER]

Hi Max,

Last year I've build such a controller with an AtMega8 microcontroller.

I've used some of the code posted on http://www.avrfreaks.net/
and add some of my own code. I've got a video of the result on youtube.

http://www.youtube.com/watch?v=5zULWFefiPE

It uses 5 dmx-channels:
channel 1: Red (0-255)
channel 2: Green (0-255)
channel 3: Blue (0-255)
channel 4: Special functions (fade etc)
channel 5: Strobe function

If you want to know more, let me know, I'll find the code and schematics for you

- Floris

[mliptack]

Thanks everyone I appreciate the fast response!

Flecom - I wanted to stick to DIY, but I might have to buy one of those anyway for the heck of it

Ray - A DMX relay board is on the right track, but FloWLaser is right on target. I needed 0-255 control of each channel to achieve millions of colors

Floris, I would love to see more of your schematics. If you wouldn't mind posting them that would be great. Otherwise I'm about to send you my email address. Honestly, I'd prefer if you emailed it to me since forums have been blocked at work during business hours (along with many other websites about 3 weeks ago).

Thanks again everyone!

I'll have to post some pictures of the results once I get there

[FLoWLASER]

Hi Max,

Please PM me your e-mail address! I'll try to find the schematics & code for you, it's somewhere on my laptop.

-Floris

[Things]

I'm going to be doing the same thing but with 20 3W RGB LED's, for a 60W RGB array

I'm going to be using an ATMega also.

[FLoWLASER]

I'm going to be doing the same thing but with 20 3W RGB LED's, for a 60W RGB array

I'm going to be using an ATMega also.

Cool project!

Just 2 questions....

How do you intend to drive the LEDS, since they require quite big current ?

And how about the cooling ? I've used some 3W Leds, and they get really hot !

[Things]

I have the LED's running fine from an ATMega328 at the moment. I am using 3 FETs, 1 for each colour.

As for cooling, everything is mounted on a ~7mm thick plate of alu, and they only just start getting warm after a few minutes of use. However, this array was calculated to draw 21A, but my current power supply is only capable of 18A on the 3.3V rail, so I may be under driving them at the moment too.

I intend to either add some heatsinking, or some forced air cooling.

[flecom]

Flecom - I wanted to stick to DIY, but I might have to buy one of those anyway for the heck of it

its $17 + $15 shipping, you cant really go wrong lol

I enjoy DIY as much as the next guy but just finding a nice enclosure would cost you almost as much as buying that thing lol