Configuring Jetson Nano Module to Output Display via DP1_TX0~3 on Custom Carrier Board

Issue Overview

The user has developed a custom carrier board designed to support both the Jetson Nano and Jetson Orin Nano modules. While the board works fine with the Jetson Nano, the user is facing challenges in configuring the display output for the Jetson Nano module to use the DP1_TX0~3 pins, which are typically associated with the DisplayPort (DP) on the Jetson Orin Nano. The user wants to block the existing DP0_TX0~3 signals and route the display output through DP1_TX0~3 instead.

Possible Causes

1. Hardware configuration mismatch: The custom board may not be properly configured to route DP1_TX0~3 signals to the DisplayPort output.

2. Software configuration issues: The device tree and display controller settings may not be properly configured to use DP1_TX0~3 for display output on the Jetson Nano.

3. Incompatibility between Jetson Nano and Orin Nano pinouts: There might be differences in how display signals are routed between the two modules, causing conflicts on the custom board.

4. Incorrect understanding of DP1_TX0~3 capabilities: The user’s assumption about DP1_TX0~3 supporting both HDMI and DP simultaneously may not be accurate for the Jetson Nano.

Troubleshooting Steps, Solutions & Fixes

1. Verify hardware design:

   • Review the schematic and PCB design to ensure DP1_TX0~3 signals are properly routed to the DisplayPort connector.
   • Confirm that the necessary supporting components (e.g., level shifters, multiplexers) are in place to handle the signal routing.

2. Modify device tree for Jetson Nano:

   • Locate the original device tree source (dts) file for the Jetson Nano.
   • Modify the tegradc (Tegra Display Controller) settings to use DP instead of HDMI:

     Original configuration:
     tegradc.0 → sor1 → HDMI setting
     tegradc.1 → sor0 → DP setting
     
     Modified configuration:
     tegradc.0 → sor1 → DP setting
     

   • Update the SOR1 (Serial Output Resource) settings to support DisplayPort configuration.

3. Compile and flash updated device tree:

   • Compile the modified device tree into a device tree blob (dtb) file.
   • Flash the updated dtb file to the Jetson Nano module.

4. Test display output:

   • Connect a DisplayPort monitor to the custom board’s DP output.
   • Boot the Jetson Nano module and verify if the display is working correctly.

5. Debugging display issues:

   • If the display doesn’t work, check the kernel logs for any error messages related to the display controller or DP initialization.
   • Use the tegrastats command to monitor GPU usage and verify if the display subsystem is active.

6. Consider hardware modifications:

   • If software modifications don’t resolve the issue, you may need to revisit the hardware design.
   • Ensure that the DP1_TX0~3 signals are properly level-shifted and impedance-matched for the DisplayPort interface.

7. Consult NVIDIA documentation:

   • Review the Jetson Nano and Jetson Orin Nano technical reference manuals for detailed information on display signal routing and configuration.
   • Check for any application notes or errata that might address similar display routing scenarios.

8. Seek professional assistance:

   • If the issue persists, consider reaching out to NVIDIA developer support or consulting with a hardware design expert familiar with Jetson platforms.

Note: The provided solution focuses on modifying the Jetson Nano configuration to use DP1_TX0~3. However, it’s important to thoroughly test this setup to ensure compatibility and stability, as it deviates from the standard Jetson Nano display configuration.