[thesh4d0w]

It's not really hard at all, calculate the max power the leds will draw and get a psu that'll never exceed 90% of that. Your average usage will be waaay lower anyways since you don't usually show all white.

5v power supplies are easily available, Meanwell is a popular & reputable brand. The same psu can run your lights and microcontroller.

[__jonas]

Newer said it was a hard problem in general, it's hard for me with my limited familiarity with electronics, that's why I was curious how it was done here.

I recall the last time I wanted to do this, my problem with it was that my microcontroller had a different voltage requirement than the LEDs and I tried to put together a little circuit that delivered the right voltage to the microcontroller and LED matrix from a single 5V power supply. I think it worked kind of ok and then not anymore and I had trouble figuring out where I went wrong, most likely did some bad soldering somewhere.

[MarkusWandel]

Fully lit, these would be blindingly bright, and would need tens of amps of power supply (source: I have a strip of 100 WS2813s (I think, anyway the 12V ones) and the 3A supply I have would be fully loaded if they were all on full bright white. These suckers are bright).

However, you can always just limit it in software. Total "brightness budget" for the display, scale everything to dimmer if exceeded.