While cool these things always make me cringe, Those outlet boxes + extension cords makes me question the safety of a setup like this.

especially if it is planned on being used outside, or inside.

If I was going to use something like this outside I would employ some type of weatherproof outlet boxes and GFCI outlets.

this may add some considerable cost to a project like this but when it comes to safety I think it is worth the extra money.

Nice build. I personally don’t like the use as the ground cable as neutral and the neutral cable being used as a hot. Should have gone to a hardware store and bought a 4 conductor wire. (black-red-white-gnd)

Also, would be cool if it supported triac-dimming.
And if the site was readable :P

Am I missing something here? DMX has 512 channels, right? So, is this even DMX? Why not run all the power separate from the controller channels? This seems a little backwards from any professional hardware I’ve used…

I don’t get it 100% either. Normally the DMX controller is the master, for instance a programmable light board or a computer.

The DMX interface itself is a serial RS485 multidrop with a slightly odd clock frequency that I can’t remember right now.

Anyway to the controller, slaves like DMX dimmer packs and other DMX controllable units would be attached, normally daisy chained, with one in and one out XLR type connector for each unit.

Since RS485 can be transmitted over some distance the DMX “slaves” can be placed where needed. The last unit will be terminated with a resistor usually inside an XLR connector.

When you are controlling lights for instance with a dimmer pack, the dimmer always lets some current through the light. That because tungsten and halogen lights don’t last long if you turn them completely off and then on repeatedly.

So I guess this should really be called a DMX relay and not a DMX controller.

There is an entire website for people who build their own Christmas light controllers.
http://doityourselfchristmas.com
DMX is one option but there are many more.

“I bet any professional hardware you have used was not built on the kitchen table either”

You’d be amazed….

I applaud the built spirit. Some of the execution, however, makes me cringe.

Get rid of the extension cord wire. As someone else already said, find some decent four-conductor cable. Most hardware stores have it.

Red and blacks are ok for hot.
White for neutral.
Green for ground ONLY. BTW, make sure you have ground continuity from your outlets all the way back to your source.

Get some waterproof outlet boxes.

I’ve been told that if you Macguyver something that is not to code, and you end up killing someone or burning your house down, your insurance may not pay up.

“Not to code”?

WTF?

No part of the NEC specifically covers strange homebuilt gadgetry that one plugs into a wall outlet.

Not that I disagree with the 4 wire and ground wire comments, but if this is strictly for Christmas lights then they tend not to have a ground anyway.

Also the colours don’t matter, who cares if ground is green, if no one else is going to look at it then you can use whatever wire you want for whatever. Just be consistant

Dmx is broken into universes. Each universe has up to 512 channels. A single fixture can use several channels. An inteli-light for example. You have channels for x and y axis, filters, and light control. The diyc site mentioned has been offering plans to build light control systems for several years. I have 96 channels built from the plans at DIYC. Each channel is designed to handle 1-2 amps of lighting. But even at that you can see that the amps can quickly add up. The switch to LEDs has helped immensely though. The systems I have built have worked incredibly well for Christmas and Halloween. A little common sense goes a long way towards keeping the systems safe.

Something else I just noticed. The relay control board and the 120VAC side are both in the same box that when closed will put them right on top of each others. That is a BAD idea. If anything shorts or a wire pulls out of a screw whatever is connected to that setup controlling it will fry.

Please change the title, as this is not a DMX controller, but only a DMX relay board.

dmx is the perfect protocol for a project like this, and those who think it’s not have no idea about professional lighting control… and should shut their little blogging fingers in the door of their car. Dmx does much more than dimming.