Hello everybody
I want to build a 3m pov wheel led screen with 144/m ws2812b
The target of this build is that a child will spin a paddle that will be connected with a belt to the wheel and will show a short animation or gif
Along with my own research and developing I thought I could use some other perspective and experience I have about two weeks to finish it so any advice will be appreciated
Since I’m planning to build it with of the shelf items it will be open source and documented
Many thanks in advance
If you go back through the group archives - @Ashley_M_Kirchner_No did a bunch of stuff with POV.
One concern is that with 432 rgb leds, you’re going to be capped at about 38fps[1]. What do you want to use as a controller? If you use the teensy there and are willing to get a little creative with your wiring you can use OctoWS2811 - which would let you write out the output in 8 lines in parallel, effectively giving you 8x the frame rate. Possibly even more, as OctoWS2811 will use the teensy 3’s DMA to push frame data out in the background.
I have preliminary code for 8-24 way parallelization on the arduino due, but I haven’t ported it to the teensy 3 yet, and it’s a bit kludgy. Also, when I get that code wrapped up, I also want to add support for OctoWS2811 directly in my library so people can use our LED management code (hsv library, fast math, etc…) with Octo’s DMA output. Now that halloween is done, I want to finalize the release of v2 of the library so that I can get working on polishing v2.1 as well as some site administrative stuff with the library).
[1] The calculation: 432 leds = 10,368 bits of data per frame (24 bits per led). Each bit takes 1.25µs to write, so a “frame” will take 12,960µs or 12.96ms to write. If you spend 100% of your time writing LED data, that’s 77fps. If you spend 50% of your time, that’s only 38fps.
Thank you very much for you quick reply
Actually thought about using 4.5m or even 6m of strips in a 3m diameter wheel so the frame rate could be reduced and I have a slip ring for solving the wiring issue so I need to check that as well other then that will check everything with mega first then I’ll order the teensy if you recommended it
Looking for the simplest and easiest way of accomplishing the pov wheel
Best regards