It's late in the semester and because time is running away way too fast, I've had to cut down unsolved problems and borrowed a commercial USB2DMX512 device that already communicates 100% with vvvv. So the Arduino DMX is delayed until I have the time to look into it ? :-X unless someone comes up with an already working solution.
I still though appreciate an explanation as to how and where 'digitalPinToPort' and 'digitalPinToBit(pin)' are defined. Any hints on that, folks?
@ Oori: I've hoped you would reveal the code you've been working on.