Stubborn WS2811 Flicker Issue

[cancolby]

Hello. I've been a LOR user for many years, just this year delving into the realm of E1.31 and "DIY" pixel-making.

 

I have a SanDevices E682 with 100 12v WS2811 RGB LEDs connected, with no issues.

 

When I solder more LEDs in, making a strand of just 200, I see a flickering / strobing issue. But when running the E682's test patterns, there is no issue.

 

If I set the grouping to 10, drastically lowering the channel count and raising the refresh rate, the problem persists.

 

The J12 jumpers are set to 12v, the power supply is ample, null pixels don't help, the strand is connected directly to the board (no extensions), and the firmware is current.

 

I don't know what else to try! Does anybody have any ideas?

 

Thanks!

Colby

[bdeditch]

Make sure LOR is completely off when testing the lights

[cancolby]

For these tests, I'm actually not using LOR yet, but a program called Lightjams.

[k6ccc]

My guess is power - or more specifically lack of it at the end of the string. How long were the strings that you are using?

[ShaggySS]

My guess is power - or more specifically lack of it at the end of the string. How long were the strings that you are using?

Yep sounds like the issue.  Inject power from the other end and see if that changes things.  Keep in mind different colors use different amounts of power.  I did lots of testing with my setup and Red, Green, and Blue were fine but when I went white which uses the most power those towards the end of the strip were red.  

[cancolby]

I've also tried running 500 pixels with power injected in six places, and 200 pixels with power injected in two places. Even with just 100 pixels I may need to add additional power? I'll give that a try soon.

[Max-Paul]

Well one of the factors why you would need to inject power at the end with just a mere 100 pixels is that you are using a small wire gauge from the controller. So what gauge wire and how long from the controller to the pixel strip(s).

[marsh28]

I agree it's probably a power injection issue

[cancolby]

Here are the pixels I'm using (but not with those connectors).

http://m.aliexpress.com/item/1603691720.html?tracelog=storedetail2mobilesitedetail

From the controller to the LEDs, there is no extension wire. They're connected right into the E682.

Thanks for the help everyone.

[k6ccc]

Part of the issue (and the reason I asked how long the strings were) is that the manufacturer of most of the pixel strings or strips assume that the wires or traces only need to carry the current for that sting. In other words, if you buy 50 pixel strings, assume that you will need to inject power if you exceed 50 pixels. So using our common strips with 30 RGB LEDs per meter on a 5 meter strip as an example, (which are typically about 36 watts) the traces on the strip can only handle the amperage required for those 36 watts. that would be a little over 7 amps if it's a 5V strip or 3 amps for a 12V strip. Since we can't generally tolerate much voltage drop or else the pixels don't work or change color somewhat, we need to be very aware of properly supplying power to the strips. I found on some 48 RGB LED per meter 12V strips that I'm using, the ends were color shifting a bit with 18 to 20 feet of strip. Injected power a little under 7 feet from each end and the problem went away.

[cancolby]

Looks like you guys were right, I just had to inject power a lot more frequently than I initially expected!

 

What is the best way to splice in extra power? My project uses 3,000 LEDs, and it looks like I'm going to need injection every 50-75 pixels… Is there a better, more efficient way than cutting the strand in two and stripping the insulation for the lights and power cable and shrink wrapping and/or soldering? This will also be outdoors. Each connection takes a few minutes to do well, there must be a better method or tool!

[k6ccc]

That's pretty much what you need to do. I would solder and then heat shrink. Don't feel too bad, I have dozens of connections on my year round landscape lighting that I knew would regularly get flooded, so I took waterproofing really serious. Never had one leak so I must have gotten it right (maybe overkill).

[ezimnow]

I used heat shrink on mine but here is another possibility ....still need heatshrink but you can use these .....www.waytekwire.com

search "waterproof"/Mizu P-25  connectors/Molex...male and female...no more soldering ....again I went with soldering and heat shrink but this may be an option

Edited October 20, 2014 by ezimnow

[saxon]

colby

 

You do not need to inject EVERY 50-75 pixel. Remember, you can power from the end of a line.

Inject power between pixel 100, 101 and 200, 201.

board-----------------50------------------100(inject)--------------------150---------------------200(inject)------------------250

 

I personal can only get about 62 pixels on white before injection is needed. This ONLY works if your power is coming from the same place, if using 2 different PS, you will have to make changes.