A few years ago, [Frans-Willem] bought a few RGB LED panels. Ten 32×16 panels ... with the data pins filling in the obvious role. The code that actually drives the LEDs all happens on an STM32F4 ...

[Stan] built this LED matrix using a 16×16 grid of RGB LEDs. He built the hardware and wrote some subroutines to randomize the colors. He’s not using PWM because frame buffering is not feasible ...