Adafruit's 32x32 RGB LED matrix panel

Ahh, thanks... I think getting multiple tones (or even something non-flickery) is going to be properly hard work without using assembler I'm afraid :(

In the code I posted:

• new Uint32Array(.. creates a 'view' of the other array (so it doesn't copy it but just lets you see it 24 bits at a time)
  
• [].forEach.call(words, function is a bit grotty (it'll be easier soon), but basically it creates an empty array, 'steals' forEach and calls it as if it was actually a function on Uint32Array. forEach will then call the function defined after it for each of the 32 bit words in the array (but it'll do it quite quickly).
  
• And digitalWrite writes data out to the pins defined in the array, but does so one at a time. That means that you can write the 3 colours out, then write a 1 to B8, and then a 0 to B8.
  
• The crazy multiply/and/shift stuff is to take the top bit of the 8 bit colour in each of 3 bytes, put them together, and move them down to the bottom 3 bits.
  
  

Anyway, that and some other tweaks should make it a lot faster, but I think you're still going to have quite a bit of trouble with it...