Mallow carrier board -verdin Am62-Lvds

Technical Support
1

I’m using the Mallow carrier board with the Verdin AM62 module, and I’m having trouble getting my LVDS display to work. I’ve added the device tree overlay **verdin-am62_panel-cap-touch-10inch-lvds_overlay.dtbo**, but the display still isn’t turning on. I’m also receiving messages like **
[ 6.020708] pwm-backlight backlight-lvds-native: supply power not found, using dummy regulator**.
but i seen back-light powered on and i also checked every power points at the display(everything fine ).

2

Hi, I’m the Toradex AI Assistant. The Toradex Support team will follow up with you shortly!

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Based on the context provided, here are some steps you can take to troubleshoot the issue with your LVDS display on the Mallow carrier board with the Verdin AM62 module:

  1. Review the Device Tree Overlay: Ensure that the device tree overlay verdin-am62_panel-cap-touch-10inch-lvds_overlay.dtbo is correctly configured for your specific LVDS display. Check that all parameters match the display’s requirements.

  2. Verify Power Supply Connections: Double-check that all power supply connections to the display are secure and that the correct voltage levels are being supplied. Even though the backlight is powered, the system’s inability to detect the power supply might indicate a configuration issue.

  3. Check Compatibility: Make sure that the device tree overlay is compatible with your LVDS display. If there are any mismatches, it could prevent the display from functioning.

  4. Signal Integrity: Ensure that the LVDS signals are being transmitted correctly. Verify that the pin configurations are correct and that the connections are secure.

  5. Kernel Logs: Look at the kernel logs for any additional error messages or warnings that might provide more context on the issue. This can help identify configuration issues or hardware problems.

  6. Consult Documentation: Refer to the documentation for the Mallow carrier board and the Verdin AM62 module for any specific requirements or troubleshooting steps related to LVDS displays.

If these steps do not resolve the issue, further investigation into the device tree configuration and hardware setup may be necessary.

Please, also check if these links can help you solve your problem:

Enable 10.1" LVDS display on Mallow carrier board.

3

Hi @Seyad!

To understand better your issue, I’ll ask a few questions.

What was the image that you’ve installed on the module? Is this display from Toradex or is it a 3rd party display?

Best regards.
Lucas Azeituno.

4

image - customised yocto project
display - 10.1 inch LVDS Capacitive Touch Display 1280x800 V1.0 - from toradex

5

Hi @Seyad!

I tested it with Torizon OS 6.7.0, and it worked. I modified the device tree overlays, added the verdin-am62_panel-cap-touch-10inch-lvds_overlay.dtbo, and could see Torizon logo while booting. Besides that, I ran a Weston container, and it appeared on the display.

Does your customized image have a graphic response? Maybe it is working, but as your image does not have anything graphical, you would see nothing.

In order to verify if the hardware or the customized image is the problem, could you please test it with our image?

Best regards.
Lucas Azeituno

6

Hi @Seyad!

Reading the datasheet, I found that the jumper JP1 must be shortened (Page 22) in order to use the LVDS display, otherwise the backlight converter won’t be powered.

Please, verify this jumper too.

Best regards.
Lucas Azeituno

7

I finally found the issue. I had used a 24-volt power supply for the Mallow carrier board, which was directly passed to the display, causing it not to work. After switching to a 12-volt power supply, everything is now working fine.

8

Hi @Seyad!

I’m glad to know that it worked.

Best regards.
Lucas Azeituno