Debug others older posted project "Uncanny Eyes"

Projects General Guidance
14

I now see the line that looks for the "C" button...

This means ... "IF nunchuck.getButtonC() is HIGH, then the second element of the array ( serCmd[1] ) will contain "I" (upper case, ninth letter of the alphabet), otherwise serCmd[1] will contain "O" (upper case, fifteenth letter of the alphabet).

Find the output of serCmd[1] on the "eyes" side... something like this...

Serial.print(serCmd[x]); // "x" is an element in the serCmd[] array
serCmd[1] = (nunchuck.getButtonC() ? 'I' : 'O');

[edit]
I believe your "C" button is broken.