How could I add 2nd and 3rd fan on AGX Orin?

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Orin
1

Hi Nvidia,

We want to add the 2nd and 3rd fan on AGX Orin / JetPack 6.2.
I just find 1 fan_tach gpio in the pinmux.
How could I set gpio to fan_tach or add gpio to hwmon?
And how could I add 2nd and 3rd Fan?

I found nvidia,gpio-tachometer function in JetPack5 but not JetPakc6.

3

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

To address your question, I’ll break down the steps to add the 2nd and 3rd fan on AGX Orin with JetPack 6.2.

Understanding the Current Setup

In the provided context, it’s mentioned that you’ve found only one fan tachometer GPIO in the pinmux. This suggests that the current setup only supports one fan.

Adding GPIO to HWMon

To add GPIO to HWMon, you’ll need to modify the device tree. The device tree is a data structure that describes the hardware components of a system. You can modify the device tree to add new GPIOs to HWMon.

Here are the general steps to modify the device tree:

  1. Identify the GPIOs you want to add to HWMon. You can use the pinmux tool to find the available GPIOs.
  2. Modify the device tree source file (usually tegra194.dtsi or tegra194-p2888-0000-p2822-0000.dts) to add the new GPIOs to HWMon.
  3. Compile the device tree source file to generate a new device tree binary.
  4. Update the device tree binary on your system.

Using the nvidia-gpio-tachometer Function

The nvidia-gpio-tachometer function is available in JetPack 5, but not in JetPack 6.2. However, you can use the gpio-fan driver, which is available in JetPack 6.2, to achieve similar functionality.

Here are the general steps to use the gpio-fan driver:

  1. Load the gpio-fan driver module: sudo modprobe gpio-fan
  2. Configure the GPIOs to use the gpio-fan driver. You can do this by modifying the device tree or using the gpio-fan driver’s sysfs interface.
  3. Update the fan configuration to use the gpio-fan driver.

Adding the 2nd and 3rd Fan

To add the 2nd and 3rd fan, you’ll need to:

  1. Identify the GPIOs to use for the 2nd and 3rd fan tachometers.
  2. Modify the device tree to add the new GPIOs to HWMon.
  3. Configure the gpio-fan driver to use the new GPIOs.
  4. Update the fan configuration to include the 2nd and 3rd fan.

Comparison with JetPack 5

In JetPack 5, the nvidia-gpio-tachometer function is available, which makes it easier to add new fan tachometers. However, in JetPack 6.2, you need to use the gpio-fan driver, which requires more configuration and modification of the device tree.

In summary, to add the 2nd and 3rd fan on AGX Orin with JetPack 6.2, you’ll need to:

  1. Modify the device tree to add new GPIOs to HWMon.
  2. Configure the gpio-fan driver to use the new GPIOs.
  3. Update the fan configuration to include the 2nd and 3rd fan.

This requires more effort and configuration compared to JetPack 5, where the nvidia-gpio-tachometer function is available.

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5

hello Wilson_Lin,

you may refer to Topic 348680 for the steps of adding 2nd fan.