Wrong Enable Pin declared in library

[jonasprobst]

This has cost me soooooo much time :-S The actual pin used on the Sparkfun DMX Shield for DMX Enable via UART Port1 are:

//SparkFunDMX.cpp
...
int enablePin = 4;      // <--- not 21!!! 
int rxPin = 16;
int txPin = 17;
...

and not GPIO21 as the DMX library code (line 18) suggests.

Thanks for updating this!