WS2818 pixels lighting nodes on both sides of a joint

[Srmorgan]

Hello everyone. I built three matrices for my windows with seed pixels. They are all exactly the same except that one is traditional three wire pixels and two use WS2818 dual signal seed pixels. As part of building the matrix I wanted to keep the 2” spacing so I cut out a node at the top then soldered the wires back together so I had more wire to make the turn to go back down.The three wire matrix works great. But the 4 wire isn’t displaying correctly. I swapped the connectors to see if it was a configuration problem, but when I reattached the connector from a problem matrix to the good matrix it worked just fine. While troubleshooting I discovered that when I lit up individual pixels I would get two that would light up when I got to a pixel right before I had cut the string and soldered it back together. I didn’t do anything to the nodes on either side but now they are lighting up just like they are a single pixel. And on one of the matrices the very first pixel doesn’t light up. But when I turn on node 2 it turns on. I have the redundant data in connected to the ground at the beginning of both matrices. I switched one so the data in was connected to both data wires to see if it made a difference. It didn’t. Any ideas of what is causing this to happen. I doubt it matters but they came from Ray wu if I remember correctly.

 

[Skymaster]

Swap the data wires at the join.
4 wire seeds alternate backup and primary data lines. So you're feeding the wrong input (backup) into the primary, which contains the previous pixels' worth of data.

 

[Skymaster]

This post here explains how they work: https://auschristmaslighting.com/threads/how-to-connect-seeds-to-controller.17034/post-144012

 

[Srmorgan]

Well, that might clear a few things up because I was very confused. I’ve already replaced one pixel in it and it didn’t cause that to happen so maybe that’s why that particular joint worked. OK so to make sure I’m understanding this correctly. I am positive at all those joints I have the primary data out connected to the primary data in. But I need to cut that and add the backup data out to the inbound primary data or do I add the backup data out to the backup data in.

 

[macmanluke]

dual signal are a fair bit of extra work when cutting and splicing as you either need to test correct line for out put when wiring or keep cuts to even numbers of pixels and not loose track of which is which data line

I went back to regular 3 wire seeds as i didnt find it worth while especially for repairs.

 

[Srmorgan]

The joys of learning the Technical things on the eve of Halloween.