Setup:
• 10 meter 24V individually addressable LED strip
• Power injection at both ends
• Controller: QuinLED Dig-Octa
• WLED firmware
The problem:
I'm getting intermittent, random flashes/glitches on the strip. The strange thing is that the signal cable type does make a difference — swapping cables changes the behavior — but I can't get the flashing to go away completely regardless of what cable I use.
The setup works perfectly with no power injection and a short 3-pin JST connector. As soon as I go to longer signal cables (needed with the 10m run and dual power injection), the flashing starts.
What I've tried:
• Multiple different signal cables — all reduce the issue somewhat but none eliminate it
• Verified power injection is working at both ends
• Works flawlessly on a short run with no injection
My current theory:
I'm suspecting a ground loop or signal integrity issue introduced by the longer cable run and/or the dual power injection setup creating a ground potential difference. Could also be impedance mismatch on the data line over longer distances.
Questions:
- Is this a ground loop issue? Should I only connect ground on one end of the power injection?
- Would a logic level shifter or data line isolator help here?
Happy to share a video of the glitching — it's subtle but clearly there. Any help appreciated!