Problem Joining WS2811 Pixel strings

[chris@itsgone.com]

Anyone know if you can join and address WS2811 Pixel strings? Got some DC5V 40 Node pixel light strings, but having problems addressing extended/joined strings with a 12s. Have tried joining the strings to extend beyond 40 pixels/nodes but only an initial few nodes light up. Also get strange results if I adjust the Pixel count in 12s. Are the 40 pixel strings fixed address length? Anyone had an experience with this?

 

[kane]

Anyone know if you can join and address WS2811 Pixel strings? Got some DC5V 40 Node pixel light strings, but having problems addressing extended/joined strings with a 12s. Have tried joining the strings to extend beyond 40 pixels/nodes but only an initial few nodes light up. Also get strange results if I adjust the Pixel count in 12s. Are the 40 pixel strings fixed address length? Anyone had an experience with this?

Yes, you definately should be able to extend the length, ensuring that you have them wired in the correct direction (ie, "data in" connected to "data out" of the first length). Each 2811 chip doesn't know where it is in the string - it basically considers itself the first item, stripping the first bit of data for itself, sending the rest of the data onwards

I'd recommend having a look at FastEddy's 101 guide (which is on the site here somewhere), as a good primer for all of this stuff - will help you a lot.

In terms of the issue you're having, it's potentially an issue with one of the pixels in the string (eg if only the first 5 light up on the second strip, something may be wrong with your 4th or 5th pixel).. As a test, I would connect the second string up as the first string and see if you get the same result.

Cheers

Kane

 

[AAH]

Pixels don't have any sort of addressing in them. All they do is grab 3 channels worth of data and pass along all the rest to the pixel stream. What you may be having issues with is a lack of power as you can quite happily run 40 pixels without needing to inject power but once you add more to the mix you will get strange results that can affect both the pixels before and after that join point as the extra load on the pixel string drops the voltage below where the pixel logic will work.

 

[chris@itsgone.com]

Hi Guys,

Thanks for your comments. Fixed the issue. It was a bad data connection on an extension and got the pixel lengths muddled up in 12s configurator. Now that I got the string lengths correctly configured all is running great!