Choosing Serial port using #define directive

Official Hardware Mega Due
2

Why so complicated?

#define SerialDEBUG Serial1
// or #define SerialDEBUG SerialUSB

void setup() {
  // put your setup code here, to run once:
  SerialDEBUG.begin(57600);
  SerialDEBUG.println("That is an test");

}