I am trying to access UART4 with pyserial. This is the port with the serial connector. However, nothing I do seems to work? what tty port is it? I am guessing it is not ttyS0?
UART4 is the debug port. You can connect that port with a UART adaptor with PC and use tools like minicom to check the function.
In device side, ‘echo test >/dev/ttyS0’, and you will see the output ‘test’ in console.
during boot, the following message will show:
[ 1.814544] serial8250.0: ttyS0 at MMIO 0x70006300 (irq = 122) is a Tegra