Null Pointer Exceptions problem

Processing Electronics (Arduino, etc.)
6

@svan, aah yes, well done. On Pi use ‘ls /dev’ to see what you have. For me, one Ard is showing as ttyUSB0, another as ttyACM0. So e.g.

  serial_port = new Serial(this, "/dev/ttyUSB0", 9600);

I think Mac will be the same.