I’ve read that the pico tops out at around 600 LEDS. How would I go about running a single pattern across 2 matrices of 400 LEDs, so 800 total? Would I need an output expander and firestorm?
Hi @slippers ,
I’m curious where did you see that 600 LEDs limit?
The Pico has the same pixel capabilities as the Standard. Both can drive many more LEDs than that, but with some things to keep in mind that impact frames per second (FPS).
Both models use the CPU to generate pixel data at the same rate. It depends on the pattern, but for ball-parking the default patterns combined average is around 48,000 pixels/sec. So with 800 pixels, you’d get around 60 FPS on average if CPU was the only limiting factor.
If driving APA102/SK9822 type LEDs the clock rate is configurable and can be very high, and doesn’t require buffering. This means the CPU will usually be the limiting factor, and get the best frame rates possible.
If driving WS2812 type LEDs, the data rate and buffering system can limit total FPS. WS2812 uses a fixed data rate of 800kbps, with 24 bits per pixel that is around 33K pixels/sec (41 FPS) max. The buffering means this happens after calculation, so the time is split. It would work, but you’d get a lower frame rate (maybe 24 FPS).
The Output Expander likewise doesn’t require buffering, and works at a data rate of about 66K pixels/sec. Usually this is high enough that the CPU will be the limiting factor. The Output Expander can then output multiple channels of WS2812 or APA102 type pixel data in parallel.
If you have 2 matrices of WS2812 type LEDs, I would use an output expander, with one channel for each.
For a APA102/SK9822 type matrices, you can probably chain them and then don’t need an output expander, though that would work too.
You don’t need Firestorm unless you have multiple Pixelblazes you’d like to coordinate over the network. That comes in handy when you have multiple Pixelblazes, e.g. if you need more than 48K pixels/sec, you can drive your matrices with a Pixelblaze for each, though that’s more complicated to set up than a single Pixelblaze with an output expander.
2 Likes
I think I may have been thinking of the DigUno board Quinled sells that uses WLED when I was thinking the limit was 600 LEDs.
Thank you for the detailed response! I’m loving the pixelblaze ecosystem and community and am looking forward to new products and updates! Speaking of which, is there a place we can find new project roadmaps or upcoming features?
1 Like
Mostly sprinkled around the forums. I don’t have an updated roadmap published.
I’m working on network sync now. Would make it a lot easier to throw a pile of PBs at a setup and act as one, less setup than firestorm and no extra components. Plus live code a bunch of devices.
Edit: It’s out now in beta! See how to use it in the announcement.
You can now make an almost arbitrarily large installation at your desired frame rate by adding more Pixelblaze.
6 Likes