how to split data (and power?) to RGB arches

bernard

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I would like to connect my 3 arches in a Y configuration instead of one next to another. The controller would be located in the center. Is it possible to split the data (and power) cable after the controller to go to each of the 3 branches and not have to be linear? Are they splitters for that? and how does it work?
 

fasteddy

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You can get away with data splitting but mileage will vary depending on many factors so I would say test and see what you can get away with. But what will happen is that all the elements will do the same thing as they will be seeing the same data.
The only data splitter I know of is Minleons smart Ts and that requires a controller that supports the splitter
 

kane

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With the layout you've specified, with the controller in the middle, if you choose a controller with at least 3 outputs (pretty much everything except a j1sys P2 which only has 2 outputs), then this would work perfectly - no splitting required. You just stick the controller in the middle, and each arch is connected to one output..

If instead, for example, you wanted the controller to be at the top of your diagram, then you could attempt what Eddy has suggested, and connect the inputs of Arch 2 and Arch 3 to the output of Arch 1 (Arch 2 and Arch 3 are therefore in parallel to each other).. The issue with doing this, is exactly as Eddy mentioned - Arch 2 and Arch 3 act the same. If each arch was 50 pixels, then you'd only be controlling 100 pixels - the first 50 pixels control Arch 1, and the second 50 pixels control both Arch 2 and Arch 3.

As mentioned, always try hooking things up as a test run to make sure it works as you expect - don't wait to the last minute!
 

bernard

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Those are great answers, Thanks! I want each arch to be independent of each others so the splitter option is definitely out. I guess one option could also be to get 3 small controllers, one for each arch. just need to find the right controller now!
 

fasteddy

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Why not just have the arches connected together even if you have them 5 metres apart and if you have them a good distance apart you could use a dummy pixel in between to regenerate the data signal. This way you may only need to inject power only between the arches
 

Habbosrus

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Are you using pixels? What software are you using? I ask this because I was planning something similar. It has been put on the back burner til next year now. I use HLS and e6804's. I still toyed around with ways to do it and HLS made it very easy. Is there a reason the controller needs to be in the centre?
I was quite perplexed with how's things work in the Xmas lighting world at the start of this year. Now I'm finding things much easier. I was definitely over-thinking things way too much. Everybody on ACL helped me think a little more laterally and things became much easier.
 

bernard

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Is the attached drawing a correct representation how the arches should be connected together if the controller does not have 3 dmx output? Still a little confused about the power injection and how to do it.
As far as software, I use Vixen 2.1. and Xlights. I started to look at Vixen+ which as Xlights as a tab for nutcracker but truly I have no idea how to use nutcracker.
The controller does not have to be in the center anymore since the splitter option is out but if the controller is on the outside of arch 1, thus the end of arch one now would be in the center but I think I would need to connect it to the outside of arch 2 (same between arch 2 and arch 3) otherwise the pixels will be out of order.
I read about the dummy pixel to regenerate the data signal but that is another thing I need to go back to better understand. If the drawing is correct, would I need dummy pixels?
Thanks for the help!
 

kane

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Yes, that will work. The only couple things:

1. The cable distance between the end of Arch 1, and the start of Arch 2 (and between Arches 2 & 3) should be as short as you can make it, so I would go for Option 2. If it's 6ft, then you will be fine, but when you start getting larger distances, you can get signal loss, and find things don't work too well - requiring null pixels to regenerate the signal for you.

2. When you say "3 dmx output", the output from a pixel controller is not actually DMX, it's SPI (not trying to nit pick, just making as clear as possible for you!)

3. How you have denoted power injection is all correct - obviously the power has +ve and -ve, so you run two wires..
 

bernard

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Kane,

Option 2 had my preference too as it will be easier to put together. Not exactly sure about the distance but 6 ft should not be too far off...and I got the message and will keep the distance as short as possible!
It is important to eliminate all source of confusion and I appreciate the correction about SPI versus DMX.
Still have to determine what kind of cables and connections I am going to need for both data and power.
 

kane

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Out of the 2801, 2811 and 1804 pixel types I have, the 2811 seems to be the most forgiving with distance. 6-8 ft (and potentially even longer) will be fine.. You should always hook it up as a test run first though, don't rely on theory, because for various reasons, things can vary.


In terms of connectors, most of us use the waterproof connectors from ray, as they are pretty inexpensive and do the job well. Makes things pretty easy to hook up if you've pre-made cables and pre-connected connectors.. The wire colours can vary a bit, but I've found myself that I've been able to use Brown or red for +VE, Blue or Black for -Ve and yellow or green for data.. I myself use both 2-core and 3-core, so that I can see at a glance which cable is for which (2-core always just used for power injection)


There's always multiple options to hook up the cabling - for example, between Controller->Arch1, Arch1->Arch2 and Arch2->Arch3 you could just run a single wire for the data. But it wouldn't hurt to run a 3-core cable, with +ve and -ve as well.


Here's one way of hooking it up:

1. At the start of each Arch, connect a Male 2-core and a Male 3-core. +ve of the strip would go to the red/brown wire of both connectors. -ve of the strip would go to the blue wire of both connectors, and the Data line will go to the yellow/green wire of the 3-core.

2. At the end of Arch 1 & Arch 2, get a 6-8ft length of 3-core cable (depending on how long you need), and connect this to the +ve, -ve and data out from the end of the strip. Then, at the other end of this cable, connect a 3-core female connector.

3. Get a 3-core cable the length required from the controller to the start of Arch 1. Connect the 3 wires directly into the green pixel connectors at the controller, and on the other end, connect a 3-core female connector.

4. Make three 3-core cables of sufficient length to go from your power supply to each of the arches. Connect a 2-core female connector to one end of each one, and connect the other end into your power supply.

You should then just be able to connect everything up...
 

kane

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And some variations, which will create more work (more soldering), but would give you more flexibility.

#2 requires having the 6-8ft cable connected to the strips permanently... Instead, you could connect a 3-core female connector directly to the end of Arch 1 and Arch 2. Then, create a 6-8ft 3-core cable with male connector at the start, and female connector at the end (or you could do what I do, and get Ray to make some custom cables for you!)

#3 requires wiring your cable into the green connectors on your pixel controller, which may not be ideal, depending on what type of enclosure you are using. In my situation, I connect a female connector to the green connectors on the controller, and a male connector to my cable, to allow easy disconnection.

#4 requires running 3 separate runs to your power supply, which may be overkill. You might be able to instead do it in a Y arrangement as per your diagram, it would just depend on the cable size and current draw of your lights.
 

bernard

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Kane,

That is a nice detailed description you gave me, thanks! I tried to draw in the attached sketch what you have described. Is it correct? (I used the colors that are shown on the picture for the RGBs I am getting, that is the reason it does not match yours http://www.aliexpress.com/item/12mm-WS2811-pixel-module-IP68-DC5V-input-full-color-note-we-updated-WS2801-to-WS2811-which/404056686.html)


Kane said:
4. Make three 3-core cables of sufficient length to go from your power supply to each of the arches. Connect a 2-core female connector to one end of each one, and connect the other end into your power supply.
Is there a reason you suggested a 3 core cable for power with a 2 core connector other than consistency with wires used?

I like the added flexibility you suggested by using more connectors and may end up doing that (not represented on the drawing).

Thanks again for your explanations.
 

kane

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Your diagram is absolutely spot on.

And yes, that was my mistake - only 2-core cable required for power injection, well picked up.

Biggest tip I'd give is be wary of wire colours (and even PCB markings), we've all had horror stories of colours being different across batches (and even in the same batches). I even had one huge batch of strips where not only the CLK and DAT were around the wrong way, but I had waterproof connectors pre-connected, but they'd used the female for the input and male for the output.. Took me a long time to work out why things weren't working!
 

bernard

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I'll be careful with the color for the wires!
I ordered some 3-core connectors but not 2-core ones so I need to find some locally (not worth shipping cost from china I guess). I did not get cables either so I think I will use alarm wire or something like that instead.

On the last arch, is there a need to "terminate" the wire? I would imagine water proofing at a minimum.
 

kane

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If you've got plenty of 3-core connectors, you could simply use those (just use the two wires), it's personal preference, and many people do that - I just prefer to be able to distinguish them.

Yeah, most people source cable locally - not too cost-effective to ship from China in small orders. That being said, I have had several cables pre-made for me in various lengths to save me making them up.. Not too cheap with shipping, but saves me the time!

With your cabling, you just want to be wary of wire gauge (thickness) to ensure that the current draw you are expecting to put through it is within it's capability. Shouldn't be an issue with the amount you're using for the arches, but always worth calculating the total current and ensuring that you won't run into issues.

(you also want to be aware of the current you're drawing so that you can ensure you don't overload power supplies)


There's no need electronically to terminate the end (not like DMX which you should terminate with a 120ohm resister).. But ideally it should be waterproofed in some way, yeah.
 
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