How to correctly set display resolution for i.MX7 Colibri + 7-inch resistive touch?

Technical Support
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I am using a Colibri iMX7 module with TorizonCore and trying to set up a 7-inch resistive touch display.
I have applied the colibri-imx7_panel-res-touch-7inch_overlay.dtbo overlay by adding it to overlays.txt and also using setenv overlays colibri-imx7_panel-res-touch-7inch_overlay.dtbo in U-Boot followed by saveenv.
After reboot, the display shows output but the image is not correct — the resolution or timings seem off. cat /sys/class/graphics/fb0/modes shows U:800x480p-0.
Could you guide me on what else I need to configure, or if I should create a custom overlay with specific timing values? Any help on debugging or best practices would be appreciated.

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Hi, I’m the Toradex AI Assistant.

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Hello! Thank you for your detailed description of your setup and the steps you’ve taken so far.

Based on your description, you are seeing a reported resolution of 800x480 in /sys/class/graphics/fb0/modes, but the official Toradex overlays for the Resistive Touch Display 7" Parallel are configured for a default resolution of 640x480 on the Colibri iMX7 when using the standard overlay colibri-imx7_panel-res-touch-7inch_overlay.dtbo. If you are getting a different resolution, here are some steps and checks to clarify and help you debug:

1. Overlay Selection and OS Version

  • Ensure you are using TorizonCore version 6.0.0 or newer, as this overlay is only supported from that version onwards (source).
  • Only specify one method to set overlays: either via the overlays.txt file or with U-Boot setenv + saveenv. Using both may cause unpredicted behavior.
    • Using overlays.txt in the boot partition is recommended for TorizonCore.

2. Hardware Connection Check

  • Make sure the display is properly connected to the carrier board and that pin 1 of the display matches pin 1 on the board connector. FFC connectors are delicate—handle the brown levers gently (installation guide).
  • Improper connection can cause incorrect detection or garbled images.

3. Test for EDID/Detection

  • The 7-inch resistive touch display is parallel and does not use EDID, but you can still verify what the kernel thinks is attached:
    find /sys/devices -name "edid"
    This is mostly for HDMI/LVDS displays, but running it can help spot if some unexpected detection is happening (reference).

4. Test with Weston/Software Stack

  • Use the Weston Wayland compositor to test if the display and touch functionality are working correctly:
    docker-compose -f /etc/docker/compose/docker-compose.weston.yml up -d
    This step checks that the software layers are working as expected (testing instructions).

5. Custom Overlay Only If Needed

  • If the image is not displayed correctly and you’ve confirmed the display is properly connected and the supported overlay (colibri-imx7_panel-res-touch-7inch_overlay.dtbo) is used, you normally should not need a custom overlay for standard Toradex 7" resistive touch displays—unless you’re using a different display model with different timings.
  • If you’re not using the Toradex 7" resistive touch display, or if you have a unique display module, then creating a custom overlay with the specific timing values would be required.

6. Next Steps

  • Double-check your overlay method and ensure only one is in use.
  • Re-seat the display connector and verify the ribbons are secure.
  • Confirm your OS and overlays are up to date.
  • If the above does not resolve the issue and you are using a non-Toradex display, please provide your display’s datasheet so timing values for a custom overlay can be determined.

For further reading on setup and troubleshooting, see:

Let me know if you’re using the standard Toradex 7" display or a different model, or if the above steps resolve your issue!

Best regards,
Toradex AI Assistant.

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I am getting this type of window.
torizon@colibri-imx7-emmc-06673350:/$ ls /boot/ostree/torizon-*/dtb/overlays
colibri-imx7_panel-cap-touch-10inch-lvds_overlay.dtbo colibri-imx7_panel-res-touch-7inch_overlay.dtbo
colibri-imx7_panel-cap-touch-7inch_adapter_overlay.dtbo colibri-imx7_spidev_overlay.dtbo
colibri-imx7_panel-cap-touch-7inch_overlay.dtbo colibri-imx7_vga-640x480_overlay.dtbo
i set overlay.txt = colibri-imx7_panel-res-touch-7inch_overlay.dtbo and after that i reboot so what i do next.

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Greetings @intersense.design,

Just to confirm, this is the 7-inch resistive display sold by Toradex, correct?

Just checking since our overlays are specific to the displays we sell.

Best Regards,
Jeremias

5

Just to confirm, this is the 7-inch resistive display sold by Toradex, correct?

yes

6

Okay thank you for confirming. I forgot to ask prior, but what version of Torizon are you running here? Also is this out-of-the-box Torizon or did you make any modifications to the OS?

We just want to make sure we’re comparing using the same versions you are using.

Best Regards,
Jeremias