I’m involved in a large scale LED project. In the past, the brains have been a Teensy 3.2 with Octo adaptor. We’re looking to upgrade, potentially to a pixelblaze.
The project uses WS2813s and has 6 channels of ~500 pixels each.
I was looking at the Serial to 8 driver on Tindie, which look almost perfect for this. But it looks like each channel has a max of 240 pixels, so that’s problematic.
Am I reading that right? Is there a workaround or some other approach to look at? It might be possible to split each line into 3 chunks and configure 3 of the 8 channel drivers, but that’s not ideal…
The 240/ch limit is based on a hardware limit. The driver board is like a mini version of the OctoWS2811. It only has enough memory for 1920 pixels, and because of the way it’s outputting them, its split across 8 channels, hence the 240/ch limit.
If you have the hardware already, it might be possible to read the driver protocol (docs and code here) on your teensy/octoWS2812 and basically turn it into a giant driver board for PB. The protocol isn’t limited, and we can figure a way to bypass/change the web interface to allow configuring > 240 pixels per channel.
At scale though, you’ll start losing FPS. Figure on 12k-45k pixels/sec generated from Pixelblaze v2, and the driver board data rate is about 66k pixels/sec.
Another option would be to drop in more Pixelblaze, and use Firestorm to synchronize the animations. With 6, each line of 500 pixels has it’s own CPU and you’d get great FPS and can keep single strips.
I’m working on a 6ch/8ch “PB Pro” version based on the esp32 that might solve all of your problems, but thats not done yet