So, what do you think about those RGB panels which are obviously cheaper and with smaller pitch than neopixels (as small as 3mm pitch).
Big-ish 64x32: https://www.adafruit.com/product/2276
3mmn pitch 64x32: https://www.adafruit.com/product/2279
bendable 64x32: https://www.adafruit.com/product/3803 (didn’t know they had bendable)
64x64, but requiring a special driver plus rPi: https://www.adafruit.com/product/3649
From what I can tell, they are all stupid row and scan displays, where basically you load up one or more shift registers for all the bits of one line, and once you’re done, you display that line.
Then, you quickly move on to the next line, and the next, down to 32 (or apparently 64 with a special extra signal line, probably to segment the panel into multiple parts that get scanned at the same time because doing a full linear 64 line scan would be too slow).
I actually have more experience with this than I wish since I wrote a bare bones driver to do this on dumb matrices:
Ah yes, I forgot the best part: colors are done with PWM color flashing and mixing, so you have to drive it even faster and flash the colors yourself at the right rate.
I realize those panel matrices are a bit smarter (and they have to be for that many pixels), but not that much smarter.
Up to now, I thought they were all thick and non bendable, but that’s been fixed.
The next problem is the row scanning that gives non nice looking artifacts if you move the panel, your eyes, or take a picture with a camera that will not open the shutter long enough to get a full frame (I’ve had this problem before).
Still, 64x64 for less than $100 pre-made is just hard to argue with. It just sucks that driving those things is so complicated compared to neopixels, and effectively requires something even faster and more real time than arduinos at some point.
Anyone still liking these? (@Jason_Coon with smartmatrix I guess)
I personally wish for higher frame neopixels that come in premade panels of 32x32, or even 64x64 with multiple data line entries in the middle for parallel driving.
What do you think?