Starting a LED cube

We’re taking our first steps in building a LED cube. I dug out some of my old panels and we tried running them from a Raspberry Pi 4 with the Adafruit LED Panel Bonnet. We made the tweak described here to use the Raspberry Pi sound hardware to generate some of the display waveforms. This improves display stability at the price of disabling sound output from the Pi. This seems a trade well worth making, in that after the update the panel display was glitch free.

The led panels are interesting. I’ve used them with an ESP32 in the past. The way that the hardware works, only one in 32 rows of pixels are turned on at any given time. The host device must repeatedly light up all the pixels in sequence. It gets even more tricky if you want to control the brightness of individual pixels as this must be performed using pulse width modulation of the multiplexed display.

The word on the street is that a Raspberry Pi 4 can drive 6 panels of 64x64 pixels. We’ve not gone beyond 3 panels of 32x32, but we are hopeful.

Next step is to order the panels….