Thread: DMX questions

There is an abundant level of information on how to sequence christmas lights in the sequencer. However there seems to be a serious tech black hole when it comes to DMX. Lots of terms, like lynx, and dongles, dip switches etc. Yet no definitive information about setting up the DMX system in ones Christmas display.

My hope in this post is that knowledgeable ppl with chime in, and help decode this bit of information.

I personally have gone this into this train of thought due to making the setup on the roof a lot easier. One RGB LED rope light can represent, up to four individual light string strands. This helps in simplifying the setup of lights on the house.

I know the 512 controllers have the Ethernet through point connections making them chain-able, whereas the little white 3 channel controllers that can be found for 3 bucks don't. So they would have to be on the end of said chain as the last element.

The white controllers have been argued as not being addressable. Well I have found this making the claim it can make them addressable.
http://www.holidaycoro.com/docs/DMXProgrammer.pdf

This of course does not make the white controllers chain-able (without additional wiring DIY). However, this could make them like I had mentioned the last item in your daisy chain of DMX controllers, like a flood lamp, or last RGB LED string.

How does the DMX system get setup? I know the sequencer has to know what items is what to properly issue commands to them. Im sure there are things that must be taken into consideration when using DMX and controller boards.

Here is a video on setting up a simple RGB flood lamp that helped me a lot. Perhaps it might help others too.
DIY DMX RGB FLOODLIGHT FOR HOME HAUNTS - YouTube

What are the dip switches for? How are they configured? What do they do?

It would be nice if the controller boards were able to communicate natively to the DMX system, and you didn't need a dongle (whatever that is) to control them.
This way we could just continue the daisy chain from the controller boards, directly into the DMX stuff. It would make life a lot easier.

What does the DMX control look like in the sequencer?
How do you sequence the RGB effects in it?
How do you address the controller?
What is a DMX universe, and how does that work in the sequencer?
Why does DMX have to run on a dongle, and not just hook in line in the daisy chain?

My personal hope is to be able to use DMX, and RGB LED light strips to outline my roof on the house and detached garage, as well as outline the 7 windows across the front of my home. While still using normal controller boards to control all the rest of the 80 to 96 channels in my yard.

Here is a picture I have of the daisy chain on the 512 controllers. Again these are only for the RGB LED strips, not the 24 million color ones with a thousand effects.

Maybe this attachment will help some.

Attached is a Link to DMX Channel Addressing.
http://www.look4ideas.com/techstuff/dmxchart.pdf

Also Information on DMX

DMX

Thanks, anything helps.

Does anyone have a wiring schematic of Ethernet cable ends? So I can make drops along a single long cable to control everything.

Originally Posted by ydeardorff

Thanks, anything helps.

Does anyone have a wiring schematic of Ethernet cable ends? So I can make drops along a single long cable to control everything.

Isn't it in the attachment I sent?

oops my bad.
Thanks

I haven't gotten through it all yet.

Also ot would not hurt to run an extra 16 gauge 1 pair ( I use red and black) of 12 volts dc of your running 12 volts lights. It will avoid power drop out over longer runs. to quote a manufacturer " its ohms "law" For a reason. it is a LAW not an approximation., Also your DMX cable should be shielded

Nothing special about the RJ45 cables. You can use off the shelf standard ethernet cables.

DMX is just how the computer communicates with the controllers. The 1st difference is you need a DMX interface dongle instead of a LOR/d-light dongle.

There are 2 different RJ45 wiring schemes. One was started by the LOR manufacturer and the other was started by the DIY community. As long as you use equipment from the same source there isn't a need for cable adapters but if you use a LYNX dongle with a LOR/d-light controller configured for DMX you have to have a cable with wires crossed for the LYNX dongle to talk to the LOR/d-light controller.

DMX addressing is simple, unit 0 to 512 (channels) per domain (network). The switched on commercial DMX equipment is for setting the address for that unit.

If you have commercial DMX equipment you have to have an adapter for the industry standard 3pin DMX connector to the DIY communitys RJ45 cabling system.

Beyond the physical connection of the DMX protocol equipment the sequenceing is the same. Actually it's simpler because you don't have to worry about controller addressing just channel addressing.

One thing cool about DMX is that you can have multiple controllers with the same DMX channel addressing and they will all respond to the same commands.

Hope that helps.

OK thanks that was a good read.

It referred to a terminator. Is that required for this application? Or is the cable just ended at the last controller?

It also stated the system cannot be reliably just T'ed to make connections (making drops). Which is what I had planned myself, since others are doing this with what seems like success. I was just going to hack splitters, and modify them so they will transmit through them, rather than an end point. This would just make a single cable with a female connection about every foot.

It also refers to pin usage. I don't know the correlation to what pin is what on the Ethernet cable. But I read that most people are using the blue pair, and then a data ground. Hell Ive never pinned an Ethernet cable before, but wires that small, are bound to cause cussing. Especially with fat fingers like mine. LOL



As far as the 12VDC power, yes, I will not run the 12VDC power through such tiny wires, even twisted together and expect good results. I will be making the power directly to each of the controllers.

It also stated that each color effect is one channel. Now does that mean on/off/dim on and off are all one channel per color, or does that soak up three channels per color?

So the dongle as its called is only a pin-verter so to speak.

What I don't understand, is why is it that the controllers whether they be LOR, or teensy lights, do not work with this protocol. Seems if the talk is a different language, it would just be ignored. And the common language to the controller would be heard. Like standing in a room with both English and foreign languages being spoken. You'll naturally key into what your able to understand. Cant the dongle just be placed on the end of the daisy chained controller boxes? I'd like to have a data port mounted on the outside of the house. I'm hoping for a single Ethernet cord connection to make setup in future years as simple as possible.

How many lights can the 3 channel DMX controller actually control? My home is 62 feet long along the eaves, and if I could run 4 - 15 feet strips with one controller that would be great.

Also, What is Lynx?


So:
I buy a large roll of Ethernet cord, wire in several drops using the blue pair and the green as the data ground.
Buy as many 3 channel controllers as I have RGB LED light strings to cover the items I want.
Apparently make, or buy a dongle (Any Links?). I just eBay'ed a dongle and Im up for the DIY if possible. 279 bucks is steep.
I found this, but dont know if its any good
Address each controller individually leaving at least a 3 channel gap between each.
Mount all the RGB strips in lexan P channels, and screw into the eaves of the house.
Then of course, power supplies (what Wattage/Amperage?) per DMX controller
lots of extension cords, a laptop and sequence like crazy!

Anything Im missing?

What do you think of this adapter AKA Dongle?

Module USB - DMX 512 | Light control | SOH.cz