Hi sumin.lee1,
What’s your carrier board for Orin NX?
Please refer to the following table from Jetson Orin NX Product Design Guide for UART.
and also refer to the pinmux table and tegra-soc-uart.dtsi.
You would get the following information of UART, there are 3 UART.
Module UART# => SOC UART#(used pins): <uart*>@\<address> - \<node> => Usage
- UART0 => UART2(PX04, PX05, PX06, PX07): uartb@3110000 (serial1) - Unused => To M.2 Key E
- UART1 => UART1(PR02, PR03, PR04, PR05): uarta@3100000 (serial0) - /dev/ttyTHS0 => General UART
- UART2 => UART3(PCC05, PCC06): uartc@c280000 (serial2) - /dev/ttyTCU0 => Debug
For uartb, it connect to M.2 Key E port, you need soldering by yourself to use.
For uarta, it could be simply used at /dev/ttyTHS0 node
For uartc, it is debug usage currently as you could output the serial console log. If you want to use it, you should disable the combined-uart and you would not get the debug messages.