https://www.sparkfun.com/products/14824
I set up the panel using a smartmatrix shield V4 and Teensy 3.6, just using the demo code, and the board has no activity.
Board is powered directly from my variable-voltage power unit. I noticed the teensy computer seems to be getting power FROM the board, which should not be possible. Additionally, I get .15+ amps of current draw on the board with nothing attached – seems like something is bad, but I didn’t see any noticeable damage to the SM components.
I confirmed that the teensy works with my (slightly smaller) adafruit 64x64 smartmatrix panel.
https://imgur.com/a/WI0y2dK ← images were too large for the board size limit.