My guess is that the Pin D8 & D9 are used for FTDI connection.
Can it also be used for other devices? If there is no signal coming through the FTDI interface?
Because I may need both UART ports (D8 & D9, D10 & D11).
Thank you,
Donald
You can use both uarts however you want. Uart1 is only used by the boot loader.
Great. Thank you, Felix.