Hi! Yes, the Jetson Orin Nano differs slightly from the original Jetson Nano in how it handles pin multiplexing and PWM configuration — especially with expansion boards like the Seeed J401.
Here’s how you can approach it:
Differences from Jetson Nano:
While the blog you referenced (PWM on Jetson Nano) is great for Nano, the Jetson Orin Nano uses a different device tree structure and pinmux configuration.
Steps to Enable PWM on Pin 32 (J401 + Orin Nano):
1. Confirm Pin Mapping on J401 for Orin Nano
Pin 32 corresponds to GPIO3_PQ.05 (on Orin Nano) — not the same as Nano.
Use this reference:
2. Edit Pinmux Configuration
You’ll likely need to modify the device tree using the Jetson Linux Customization Guide ( [Welcome — Jetson Linux
Developer Guide 34.1 documentation]).
-
Generate the pinmux spreadsheet via NVIDIA tools
-
Set pin 32 (PQ.05) to PWM mode
-
Compile DTB and flash using SDK Manager or manual flashing
- Check Jetson PWM Driver
Load the driver if it’s not already:
sudo modprobe pwm-fan
- Use /sys/class/pwm/ Interface
After enabling, you should see:
/sys/class/pwm/pwmchip0/
Export and control PWM via:
echo 0 > export
echo 1000000 > pwm0/period
echo 500000 > pwm0/duty_cycle
echo 1 > pwm0/enable
Extra Resources:
-
NVIDIA Jetson Orin Nano Developer Kit Docs
-
Jetson Linux Pinmux Reference
-
Robocraze’s Nvidia Jetson Nano Page (good for kits & guides if you’re in India)
If I manage to test this setup on the J401 in the next few days, I’ll report back. Let me know if you’ve tried any specific DT overlay or Jetpack version — that can affect compatibility.
Cheers!