Controlling CAM1_PWDN on Jetson Orin Nano Developer Kit

Issue Overview

Users are experiencing difficulties in controlling the CAM1_PWDN (Camera 1 Power Down) signal, also known as GP161_SPI5_CLK, on the Jetson Orin Nano Developer Kit. The specific issue involves:

• Inability to send a signal to CAM1_PWDN/GP161_SPI5_CLK
• A camera is connected using MIPI/CSI interface
• The goal is to control the camera’s power using the Jetson Orin Nano Developer Kit
• Attempts to set the mode to Tegra SoC and send output to GP161_SPI5_CLK have been unsuccessful
• GPIO input/output functionality works using a Python library, but not for this specific pin

This issue impacts the ability to manage camera power, which is crucial for efficient power management and control in embedded vision applications.

Possible Causes

1. Incorrect pin configuration: The CAM1_PWDN pin may not be properly configured for GPIO control.

2. Software limitations: The Python library being used might not have direct access to control this specific pin.

3. Hardware restrictions: There could be hardware-level limitations preventing direct control of the CAM1_PWDN pin through standard GPIO methods.

4. Driver issues: The camera driver might be overriding or blocking access to the CAM1_PWDN pin.

5. Misunderstanding of pin functionality: The CAM1_PWDN pin might require a specific protocol or method to control, different from standard GPIO operations.

Troubleshooting Steps, Solutions & Fixes

1. Use GPIO API in sensor driver:

   • As suggested in the forum, the recommended approach is to control the CAM1_PWDN signal using the GPIO API within the sensor driver.
   • This method ensures proper integration with the camera subsystem and avoids conflicts with other hardware components.

2. Implement driver-level control:

   • Modify or create a custom camera driver that includes GPIO control for the CAM1_PWDN pin.
   • Example pseudo-code for driver implementation:

     #include <linux/gpio.h>
     
     // In your driver initialization
     int cam1_pwdn_gpio = <GPIO_NUMBER_FOR_CAM1_PWDN>;
     gpio_request(cam1_pwdn_gpio, "CAM1_PWDN");
     gpio_direction_output(cam1_pwdn_gpio, 0);  // Set initial state
     
     // Function to control camera power
     void control_camera_power(int state) {
         gpio_set_value(cam1_pwdn_gpio, state);
     }
     

3. Check NVIDIA documentation:

   • Review the Jetson Orin Nano Developer Kit documentation for specific information on controlling camera power.
   • Look for any restrictions or special procedures for managing the CAM1_PWDN signal.

4. Utilize NVIDIA JetPack SDK:

   • Ensure you are using the latest version of JetPack SDK, which might include updated drivers and utilities for camera control.
   • Check if there are any specific APIs or tools provided by NVIDIA for camera power management.

5. Investigate I2C control:

   • Some camera modules may require I2C commands to control power states.
   • If applicable, try using I2C communication to send power control commands to the camera.

6. Consult camera module documentation:

   • Review the documentation of your specific camera module for any unique power control requirements or protocols.

7. Use sysfs interface (if available):

   • Check if the CAM1_PWDN pin is exposed through the sysfs interface.
   • If available, you can control it using shell commands:

     echo <GPIO_NUMBER> > /sys/class/gpio/export
     echo out > /sys/class/gpio/gpio<GPIO_NUMBER>/direction
     echo 1 > /sys/class/gpio/gpio<GPIO_NUMBER>/value  # To set high
     echo 0 > /sys/class/gpio/gpio<GPIO_NUMBER>/value  # To set low
     

8. Seek NVIDIA developer support:

   • If the issue persists, consider reaching out to NVIDIA developer support or posting a detailed query on the NVIDIA Developer Forums with your specific camera model and configuration details.

Remember to always refer to the latest documentation and guidelines provided by NVIDIA for the Jetson Orin Nano Developer Kit, as hardware-specific details and best practices may evolve over time.