It’s the Sparkfun BOB-12009 I’m using, which is the replacement for the one you link there @Kasper_Kamperman .
What is the longest length of a cat5/6 cable someone here ever used successfully between the level shifter and the leds?
I’ve run 50’ cables successfully
@Robert_Atkins I had a similar issue when plugging the USB cable in, with a solid white fill I would get a kind of rippling effect until I unplugged the USB.
Hm. Difference in ground potential between the computer and the PSU maybe? I can’t think if the computer was plugged into the mains when I was having the issue or not. Will do the experiment when I get home tonight.
I had a similar problem a while back and that was the reason. My LEDs were powered from a power supply and my arduino from my PC’s USB port. But when I connected the grounds together all my flickering went away.
All the grounds are connected though… I think. Maybe I’ve got to cut/join that power trace on the Teensy?
Usually these types of problems are due to inadequate grounding.
See subsequent post, but it turned out to be the Sparkfun level shifter I was using.