Tiled Neomatrix on different pins - only first defined works

[johnwasser]

@nifty950

Serial seems to kill the ability to light the LEDs. This makes no sense to me.

Serial requires a buffer in memory. You are very short on memory. If you DON'T use Serial you can fit one 16x16x2 matrix but not two. If you DO use Serial you can't even fit one. Makes sense to me