Maximum distance between WS2811 pixel nodes

hastings

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Oct 18, 2013
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Hi, I am planning to line my my house eves with the technicolor intelligent WS2811 RGB LED strings (12V 3 wire) with the C9 covers. I have searched and never found the max distance between pixel nodes allowed. I have some nested "A" frame eves so I need to cut some strings to run wire to where the lights will begin again.


I plan to inject power for each full length string. Where can I find the max length of wire for data between nodes so I can complete my design? Thank you in advance for any direction you can offer.


K
 

fasteddy

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The 10 metres is really a giude as some will get that and others wont, some may even get a lot more distnace as there are many things that can determine the maximum distance, like the cable used and local interferance. Another thing that also seems to play a part with Rays lights is sometimes the quality of the chip because these are copies and not originals.

You also need to remember that voltage drop is also a consideration and at 10 metres using 5vdc or even 12vdc lights may be an issue with voltage depending on the guage of the cable used and the load.

You need to test and see what works for you and also test in situ because what may work on the bench may not in fact work in the field

you can use coax cable to extend the distance as some guys here have had success with running over 50 metres without signal amplification or using dummy pixels, so thats also an option.

So test test and test some more
 

gerry

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hello K,

Welcome . I don't think you can get 10 m. I think that you would be lucky if you got 5 metres without an issue on full white. Personally I don't go over 3 metres without planning for null pixels which I do right from the start (though 4 metres has worked quite well).

I also inject power at least every 5m of pixels (if using 12V strip) which is what I had last year.
 

hastings

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Thank you. Good to know the length for reliability is less than 3 meters. Just to clarify, is 4 meters still reliable without a null pixel?
 

fasteddy

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hastings said:
Thank you. Good to know the length for reliability is less than 3 meters. Just to clarify, is 4 meters still reliable without a null pixel?
I have used up to 6 to 7 metres reliably in the past, so each situation is different so what may work for you may not work for others and vise versa. I have also had issues with 1 or 2 metre due to weak pixels
 

AussiePhil

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My personal experience with 2811 strip at least (same 2811 chip) is that 3.5M has never been an issue, over that you have to test your setup in situ and with each controller you plan to use.

Like Eddy said, what works on the bench doesn't always work in the yard.

Most people will also quote controller to first pixel, not the pixel to pixel distance, I try and keep all pixel to pixel connections under 4M were possible.

whatever you do TEST it, what works for me/us may not work for you.
 

logandc99

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I have several sets of 2811 strips and nodes where 6m works fine but I make 6m my limit.
 

fmt1962

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I have just completed a major series of tests on my new display and one of the key features I wanted to check was to make sure everything works reliably, in particular, to make sure I don't get problems with data feed and determine the maximum distance between pixel nodes.

So I undertook a whole day of testing with both WS2811 pixels and WS2812B strips... and well... I ran out of data leads at 40 meters and could not get any pixels to fault! I ran my fastest sequences for over 30 minutes at a time and could not see one pixel dropped anywhere!!! Wow, and I was so worried when everyone is talking about 3-6 meters.

I must be doing something right :)

So what is my set up?..... all LED's are 5V so voltage drop was my first challenge.

Strips
http://www.aliexpress.com/store/product/BLACK-PCB-5m-DC5V-WS2812B-led-pixel-srip-IP68-30pcs-WS2812B-M-with-30pixels-waterproof-in/701799_1846623152.html

Pixels
http://www.aliexpress.com/store/product/DC5V-50nodes-WS2811-addreable-LED-pixel-module-pixel-string-IP68-rated-RGB-full-color-256-gray/701799_32225918892.html

To avoid having huge thick power feed cables, which would cost a fortune and I would still get voltage drop problems, I purchased 20 x buck converters
http://www.aliexpress.com/item/waterproof-DC-DC-buck-convertor-DC-12V-24V-8-5V-40V-input-5V-25A-125W-output/1675239768.html

So each element has a buck converter right at the first LED. The feed from the controller box is 24V and my data/power feed cables are ordinary domestic 10amp 3 core extension leads. So power feed is easy, power supplies are all with the controllers and I don't care much about the voltage drop as it is regulated at the first LED by the buck converter, sweet!

Has anyone else tried this combination, buck converters at the LEDs and 3 core extension leads for power+data? It is working a treat for me :)
 

Goliath

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Wouldn't there be some legality/risk using 240v cabling for this low voltage? Or do you change the ends?
 

AAH

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I should imagine that he is swapping out the ends as it is reasonably unsafe using them and they are also a bit unwieldy. The 3 core and 4 core extension leads that Ray Wu sells are actually made from mains cable. I can't remember what is in them but I suspect that it may be 0.75mm2 cable.

Goliath said:
Wouldn't there be some legality/risk using 240v cabling for this low voltage? Or do you change the ends?
 

fmt1962

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Hi all,

Yes I cut the plugs off and replaced them with the 3 pin ones from Ray Wu, that way people cannot accidentally plug them into 240v.

I found it was cheaper to buy the ready made leads and cut the ends off, rather than to buy the cable off the roll.

Anyway did some more testing on Thursday night and found I started to get pixel drops at around 45mtr, so running out to 20-30m appears quite ok with this cable.

The buck converters are right at the first pixel of the strings, I just put a 3pin Ray Wu socket on the output of the converter and a matching plug on the LED/strip end and that is it, so the 5V is as close as I can get... works a treat.
 

fmt1962

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Wow, what a surprise....

As I posted previously, I was able to get some great distances between pixels using this 5v strip....

http://www.aliexpress.com/store/product/BLACK-PCB-5m-DC5V-WS2812B-led-pixel-srip-IP68-30pcs-WS2812B-M-with-30pixels-waterproof-in/701799_1846623152.html] [url]http://www.aliexpress.com/store/product/BLACK-PCB-5m-DC5V-WS2812B-led-pixel-srip-IP68-30pcs-WS2812B-M-with-30pixels-waterproof-in/701799_1846623152.html
[/url]

However I have just finished the roof and I have been using this 12v strip.....

http://www.aliexpress.com/store/product/BLACK-PCB-WS2811-LED-digital-strip-30-48-60-leds-m-10-16-20-pixels-m/701799_32250015130.html] [url]http://www.aliexpress.com/store/product/BLACK-PCB-WS2811-LED-digital-strip-30-48-60-leds-m-10-16-20-pixels-m/701799_32250015130.html
[/url]

And wow... I was getting major problems with a cable run of 4 meters!!! Lights would flicker and go out of control.

Put a null pixel in the middle breaking it into 2x 2m cables and all is perfectly well.

It goes to show that the strip itself can have a HUGE impact on the cable length you can use... I was stunned at the difference.

I am running 16 mini trees with 5-15m feed cables on the 5v strips without any problems. But 4m pulls up the 12v strip!
 
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