potatofarmer:
I also wonder what serial port lights up the tx rx lights i have yet to see them light on two everys using Serial1It would mean “Every”thing to get a second serial on a board the size of a nano.
As you have discovered, the standard serial port drivers are somewhat lacking. I've had them lock up and only recover with a board reset or reissuing of the call to begin. Problem has eluded me, but I've gotten the ports to work by just not using the standard Arduino Serial library.
The TX and RX lights are connected to the RX/TX pins between the SAM microcontroller (the USB computer interface) and the ATmega4809, not to any board pins. This is device Serial in the library which is USART3 in the microcontroller.