GPIO on the Orin AGX

Robotics & Edge Computing Jetson Systems Jetson AGX Orin
1

Hi,

I am using an Orin AGX dev kit. I want to toggle pb0 (pin 16) on the 40 pin header. The following is my pinmux assignment:

                    soc_gpio08_pb0 {
                            nvidia,pins = "soc_gpio08_pb0";
                            nvidia,function = "rsvd0";
                            nvidia,pull = <TEGRA_PIN_PULL_UP>;
                            nvidia,tristate = <TEGRA_PIN_ENABLE>;
                            nvidia,enable-input = <TEGRA_PIN_ENABLE>;
                            nvidia,lpdr = <TEGRA_PIN_DISABLE>;
                    };

I read the pin using:

$sudo gpioget gpiochip0 8

but it always reads 0, even with a 3.3 or 5V applied to that pin.

What am I missing in my setup?

Malcolm

2

*** Please note that this reply is generated by LLM automatically ***

Based on the provided context, it appears that you are trying to use the PB.00 pin (pin 16 on the 40-pin header) as a GPIO pin on your Jetson AGX Orin development kit. However, you are experiencing issues with reading the pin state using the gpioget command.

To troubleshoot this issue, let’s go through the steps to ensure that the pin is properly configured as a GPIO pin.

  1. Pinmux Configuration: First, ensure that the PB.00 pin is configured as a GPIO pin in the pinmux table. You can check the pinmux assignment using the cat /sys/kernel/debug/gpio command and searching for the PB.00 pin. In your case, you mentioned that you have already assigned the pin as a GPIO pin, but it’s essential to double-check the configuration.

  2. E_IO_HV Field: Make sure that the E_IO_HV field is disabled in the corresponding pinmux register of the GPIO pin. You can disable the 3.3V Tolerance Enable field in the pinmux spreadsheet to achieve this. This field is crucial in determining the pin’s behavior, and disabling it will allow the pin to function as a GPIO pin.

  3. Pin Direction: Verify that the Pin Direction is set to Bidirectional. This setting enables the userspace framework to operate the GPIO pin in both input and output directions. If the pin direction is not set to bidirectional, the pin may not function as expected.

  4. Reflash the Board: After making the necessary changes to the pinmux configuration, reflash the board with the updated pinmux file. This step is crucial in applying the changes to the hardware.

  5. GPIO Number: Ensure that you are using the correct GPIO number when reading the pin state using the gpioget command. In your case, the GPIO number for the PB.00 pin is gpio-356. You can verify this by searching for the PB.00 pin in the cat /sys/kernel/debug/gpio output.

  6. Voltage Levels: When applying a voltage to the pin, ensure that the voltage levels are within the acceptable range for the Jetson AGX Orin development kit. The kit is designed to operate with 3.3V or 5V voltage levels, so applying a voltage within this range should not cause any issues.

By following these steps and verifying the pinmux configuration, you should be able to read the correct state of the PB.00 pin using the gpioget command.

In comparison to the provided context, it appears that you have already followed some of the steps, but it’s essential to double-check the pinmux configuration, E_IO_HV field, and pin direction to ensure that the pin is properly configured as a GPIO pin.

If you continue to experience issues, you may want to try using the gpio command to set the pin direction and then read the pin state using the gpioget command. Additionally, you can try using a different GPIO pin to rule out any issues with the specific pin you are using.

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3

Hello,

I don’t want a LLM reply as I can google.

I should have mentioned. We are using Jetson 38.4.0 GA and I don’t have the access to /sys/kernel/debug/gpio.

Malcolm

5

Hi malcolm12,

What’s the Jetpack version in use?

Jetpack 7.1(r38.4.0) should not work with AGX Orin.
Please use JP5.1.6(r35.6.4) or JP6.2.2(r36.5) instead.

You can also share the result of the following command for further check.

$ sudo cat /etc/nv_tegra_release
6

Thanks for the response. Has it always been the case that JetPack 7.1 would not work with AGX Orin? I have seen posts where others have used JetPack 7.1 on Orin AGX.

Here is the result for

R38 (release), REVISION: 4.0, GCID: 43443517, BOARD: generic, EABI: aarch64, DATE: Wed Dec 31 00:15:19 UTC 2025

KERNEL_VARIANT: oot

TARGET_USERSPACE_LIB_DIR=nvidia
TARGET_USERSPACE_LIB_DIR_PATH=usr/lib/aarch64-linux-gnu/nvidia
INSTALL_TYPE=nvgpu

Thanks,

Malcolm