Panel chaining with ESP32 not working well when many pixels are on?


#1

Hi @Louis. I’m using 96x32 with 3 panels.

It works fine, until I connect the output of the first 3 panels into the next 3 to get mirroring using whatever is shifted out for ease of wiring and not having to split the original cable in 2.

Sadly, when too many pixels are on, I get this on the 2nd set of panels, mostly on panels 5 and 6 in the chain:

Any ideas?
(as a reminder smartmatrix only knows that there are 3 panels and I rely on shifting to fill the next 3 from bits shifted from the first 3 panels)


#2

Well, I’ll leave this for others in case it helps:
I didn’t expect it to be a power problem because I injected power on panels 1 and 4 and only panel 6 (and sometimes 5+6) was having problems.
Turns out the problem was power nonetheless. My bench power supply is only 5A and that’s not enough. I guess because of how the rows get refreshed one after another, somehow only row 6 (and sometimes 5) were impacted.
More power fixed the issue.

Sure, I guess I do have 12288 pixels total, but I expected them to use less power than my 1536 neopixels, but turns out they’re about the same.