Debug UART (Internal Use Only)

We didn’t enable the debug UART in the mass production version. However, if our partners need to use the debug UART to port a custom OS or special driver, please refer to the following steps and proceed with caution.

The position of Debug UART

We didn't expose the debug UART on the panel; instead, it is accessible through internal 2.54mm DuPont headers. Please remove the belly cover carefully, and remember to place the O-ring correctly before putting the belly cover back on.

A special GPIO to enable Debug UART

If you want to enable the debug UART immediately after the Jetson is powered on, you will need to enable GPIO3_PAC.07 (GPIO12/E10) by updating the the pinmux.

This involves modifying the relevant files and reflashing the Jetson module after applying the pinmux changes. We assume that you have already created an L4T folder with the NRU tarball extracted.

File name: L4T/bootloader/Orin-nru230-gpio-default.dtsi

gpio_main_default: default {
    ...
    gpio-output-low = <
        ...
-       TEGRA234_MAIN_GPIO(AC, 7)
        ...
        >;
        
    gpio-output-high = <
        ...        
+       TEGRA234_MAIN_GPIO(AC, 7)
        ...
        >;
        
};