[JasonACT]

SOB (in my case, all meanings, but son-of.. mainly)...

I started testing my spare sat-nav unit this arvo, it starts /dev/ser5 at 57600 BAUD, by software changes it to 9600 to listen to the sat-nav-chip, sends a command to change the chip to 115200 (along with ser5) where it remains at.

Well, the Nano only has 1 serial port and I was (going to) use it to cut the serial wire line between the nav-chip (TX) and the main CPU (RX) and connect both to it. Now I need another serial port (which the Nano doesn't have) to listen to the main CPU TX line for the command to change BAUD rates.

I might as well pick a 3.3v unit (and that will be more expensive). So what I've posted previously will only ever work on a non-sat-nav unit. I think this project is going to be on hold indefinitely for the sat-nav units. Since the new microcontroller is going to turn on and off with the battery saver, I will need to work out a way to know the "currently set BAUD rate" when it powers up each time the car is unlocked.