Driving an AUO LVDS display with an Apalis Evaluation Board (iMX8QM)


We have successfully driven a 12.3-inch AUO LVDS display (#C123HAN02.1) from our inhouse motherboard (incorporates an Apalis iMX8QM module #00371001) in a Linux environment.

However, we are unable to attain functionality from that same display when connected to an Apalis EVM using the same iMX8QM module; one error message we saw was imx-drm display-subsystem: parent device of /ldb@572410e0/lvds-channel@0 is not available

Attached to this post is my translation table which maps Apalis EVM’s X13 to the AUO display connector. link text

Any hw/sw tips/questions are appreciated!!


Hi @PaulM and Welcome to the Toradex Community!

Could you provide the version of the Hardware (including CarrierBoard) and Software of your module?

Unfortunately your files were not uploaded.

Could you please share the following:

  • dmesg.log in a File
  • devicetree file

Best regards,

Thanks for your prompt response, Jaski! Here is the reply from our developer:

Hardware: Apalis i.MX8QM 4GB WB V1.0A, Toradex Apalis Evaluation Board Rev. 1.1
Software: NXP i.MX Release Distro 4.9.51-mx8-beta

Documentation about the cable being used: see attached XLS

Reset: The RESET signal is now connected just to +3.3V. I’m not sure it’s correct. The datasheet says it should normally be high, but the power ON sequence shows it should go from LOW to HIGH only after (1-20 ms) power is ON. I didn’t connect backlight yet. I’m not sure though if the screen should be completely black or not without it.

Are you using the X17 power connection (12V supply) on the evaluation board? Yes

What are the settings of JP2 and JP3? JP2: 2-3, JP3: 2-3, LVDS1_SEL_1 / LVDS1_SEL_2 set to 5V_SW

What have you tried so far, and what have you seen on the screen in those cases? We just connect AUO LCD display with our custom cable to EVM, started Linux and did not see any response on the display.

Three attachments: link text

HI @PaulM

Thanks for the information and the files.

Regarding Hardware, the Apalis i.MX8QM 4GB WB V1.0A is not supported any more. Please check with your local Sales Team to get the newer version V1.0B of the module.

Thanks and best regards,

Now that our prototype PCB is done, we have exchanged it with the Apalis EVM. We have demonstrated that the LCD display works with our prototype PCB. Therefore, there is no need to continue this discussion thread.

Thank you Jaski for your time on this matter. This thread can now be closed.

Perfect that your prototype PCB work. You are welcome.

Thanks for the feedback.

Best regards,