Hi I am creating a permanent installation using an arduino. The install needs to start up and run on its own on a mac mini. I have noticed that the arduino jumps between serial port a and c every time I restart the computer. I tried to get around this by including message "port usbserial-A4001lMt, open" but I'm worried that this will change too. Is there anyway to get around this or to specify whichever port the arduino is using every time?