Recently our team acquired AndyMark's
addressable LEDs and their
ethernet arduino to control it, and I was the one who was trying to get it working. I used their
example code, which worked perfectly, so I decided to just add some ethernet code to it to allow it to communicate with the robot. However, the code kept freezing up whenever I tried to call FastLED.show() (which updates the LED strip) after trying to receive communication from the ethernet connection (in other words, the function hung the second time it was called) and I could not seem to figure out why.
Well, as it turns out, pins 10-13 on the board are reserved for ethernet communication, even though they are not connected and can have things plugged into them, and that's not particularly well advertised. Moving the data and clock pins to 8 and 9 was enough to fix it, and now we can have adressable LEDs that can be controlled via ethernet by the robot.