Random flickering issue on Digquad with added new string

Issues
1

I have a random flickering issue with a third pixel string I added to my DigQuad. I’m using 12V seed pixels purchased from AliExpress. Strings are all good, I know, because I used them with a previous setup with no issues.

With my DigQuad (running WLED 15.2beta, downloaded from quindor github), first string has 103 pixels, connected to GPIO1 (LED2 on the DigQuad), second string has 134 pixels, connected to GPIO3 (LED3 on the DigQuad). Both of these have fairly long run from control box to first pixel (about 25 ft first string, and 12 feet second), using three wire conductor, and switching the resisitors on the DigQuad to 33ohm. These have been working fine, with no issues for about 3 months. Power supply is 12V 300W (25A) supply.

Problem is with my third string, which has 414 pixels, and have just added. Run from control box to this string is only about 3 feet. If I hook this up to either GPIO16 (LED1) or GPIO4 (LED4) on the Digquad, I get random flashing of this string, and only this string. In my previous setup, I had this string attached to the DigQuad by itself, with no issues whatsoever. I replaced the three conductor cable I initially had, with three separate wires (power and data), but that didn’t seem to make any difference (and interestingly, with the separate wires, I still have to have the resistor setting at 33ohms, or I get even worse flickering – I thought with separate wires the 249ohm resistor setting should be fine for a 3 foot power/data run??). Power to this string is only at one end - could this be the problem? I had it set up like that previously though when it was the only string, with no issue.

I have checked data/power connections between the string and the DigQuad and they all seem secure.

2

With a 3 foot cable the resistor setting probably shouldn’t make much if any difference because everything is so close together. Do you have a picture of the wiring? I wonder if something else is off. Could also be a failing pixel, might be worth trying the strip directly plugged into a controller.

3

PXL_20251122_165824267.MP
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Here is control box and wiring. Admittedly, when it was working previously without issue, it was plugged directly into controller.

4

Try it without the wago block and see if it works.

5

having AC right next to the sensitive data signals is not a good design choice and may be the root of your issue.

6

Are you saying the AC terminal strip below (and behind) the lever block is poorly positioned? It is true that I had a different config before when I wasn’t having problems (setup was more temporary in a larger enclosure. And I’m only now realizing, after trying to deal with this problem, how sensitive the data line issues can be. I will look to do some reconfiguration of the control box. Thanks!

7

yes, AC lines can introduce noise, on a system that is already at the edge with stability, this can push it over the edge. Just a possibility, before rearranging everything, try to just take the controller and data lines further away from the AC lines and test.

8

At least put it as far as from the data line as the spacing between the data and ground wires in your circuit. Ideally significantly more than this distance. That way any induced voltage will be common to both lines and tend to cancel out rather than differential between them (and thus add).