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Setting up Displays with Torizon

 

Article updated at 17 Sep 2020
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Select the version of your OS from the tabs below. If you don't know the version you are using, run the command cat /etc/os-release or cat /etc/issue on the board.

Torizon 5.0.0

Introduction

During the development cycle of a product with a GUI, you usually go through 3 phases when it comes to displays:

Evaluation: often, you will do a basic evaluation using a regular monitor over VGA/DVI-D/HDMI - or similar interfaces, if available. We provide an out-of-the-box experience, where you just have to plug in the monitor and power-on the hardware.

Proof of Concept: even with the advantages of cross-development tools and IDEs enabling a good experience for developing GUIs in a development computer, it is often common to make tests on the real end device. We sell touch screen displays that either deliver an out-of-the-box experience or a fairly easy configuration.

Prototype and Beyond: often, you want or need a custom display in your final product. The reasons are various: price, robustness, brightness, size, interface, EMI compliance, among others. Supporting a custom display is not an easy task for a beginner, especially if you use a display with bad documentation and Linux support. We document how to enable a custom display, but you must expect that some effort is associated with the process or, alternatively, hire a partner to do the integration for you.

Toradex tests and recommends the following displays to be used with its Computer on Modules (CoM) during early phases of development:

For these displays, Toradex provides an easy way to set-up and get running, by providing ready-to-use device tree overlays. It also means that you can tweak the existing overlays to support other displays as well. This article explains how to set up displays on Torizon.

This article complies to the Typographic Conventions for Torizon Documentation.

Configure Displays and Touch Controllers provided by Toradex with Torizon

See below the list of available Device Tree Overlays provided by Toradex and how to build, validate and enable it using Developer Tools Container.

Displays

Toradex provides Device Tree Overlays for the Displays available in the webshop.

Overlay Device
display-edt5.7-overlay.dts Enable the 5.7 inch display (EOL) for Colibri imx7, Apalis iMX6, and Colibri iMX6
display-edt7-overlay.dts Enable the 7 inch display (EOL) for Colibri imx7, Apalis iMX6, and Colibri iMX6
display-lt161010-overlay.dts Enable the 7 inch parallel display for Colibri iMX7, Apalis iMX6, and Colibri iMX6
apalis-imx8x-display-lt161010-overlay.dts Enable the 7 inch parallel display for Apalis iMX8X
colibri-imx8x-display-lt161010-overlay.dts Enable the 7 inch parallel display for Colibri iMX8X
display-lt170410-overlay.dts Enable the 10.1 inch lvds display for Apalis iMX6
apalis-imx8qm-display-lt170410-overlay.dts Enable the 10.1 inch lvds display for Apalis iMX8
apalis-imx8x-display-lt170410-overlay.dts Enable the 10.1 inch lvds display for Apalis iMX8X
apalis-imx6-lvds-overlay.dts Apalis iMX6Q requires a secondary overlay to enable the LVDS interface
apalis-imx6-parallel-rgb-overlay.dts Apalis iMX6Q requires a secondary overlay to enable the parallel RGB interface
colibri-imx8x-disable-parallel-rgb-overlay.dts Disable the parallel RGB interface on Colibri iMX8X

Touch controllers

Toradex provides Device Tree Overlays for the Touch Controllers for the Displays available in the webshop.

Overlay Device
apalis-imx6-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Apalis iMX6
apalis-imx8qm-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Apalis iMX8
apalis-imx8x-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Apalis iMX8X
colibri-imx6-aster-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Aster + Colibri iMX6
colibri-imx7-aster-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Aster + Colibri iMX7
colibri-imx6-eval-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Colibri EVB + Colibri iMX6
colibri-imx7-eval-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Colibri EVB + Colibri iMX7
colibri-imx8x-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Colibri iMX8X
apalis-imx8x-ad7879-overlay.dts Enable the resistive touch controller (AD7879) on the Apalis iMX8X module
colibri-imx8x-ad7879-overlay.dts Enable the resistive touch controller (AD7879) on the Colibri iMX8X module

Starting the Developer Tools Container

To to build, validate and enable overlays you need to use the dtconf command inside the Developer Tools Container.

Therefore, the first step is to start the Developer Tools Container.

Enable overlay

After selecting the corresponding Device Tree Overlays for your board, module, display and touch screen controllers from the table above, you need to activate it.

To enable the overlay for your display, you need to be in the interactive shell inside the Torizon Debian Dev Tools container on the Toradex Computer on Module (CoM), as explained earlier.

The following command will list Toradex provided overlays:

## dtconf status

Once you've identified the correct overlay for your setup you may use dtconf activate <file> -c device_tree_base.dtb to apply your capacitive touch overlay. You shall specify on which "base" device-tree you will apply your overlay with the flag "-c" followed by the *.dtb file of the given device-tree.

As an example, to enable enable the 7" parallel display for Apalis iMX8QM on an Apalis Evaluation Board (as a base device-tree), we use the following command:

## dtconf activate apalis-imx8qm-display-lt170410-overlay.dts -c fsl-imx8qm-apalis-eval.dtb

Attention: Replace the .dts file with the corresponding overlay file for your setup ( Carrier Board + Module + Display/Touch Controller model), as the table showed in the previous sections.

To enable the touchscreen for the touchscreen controller of Apalis iMX8QM:

## dtconf activate apalis-imx8qm-atmel-mxt-overlay.dts -c fsl-imx8qm-apalis-eval.dtb

Note: Note for Apalis iMX6: Apalis iMX6Q requires an additional overlay when enabling the LVDS interface (apalis-imx6-lvds-overlay.dts) or the parallel RGB interface (apalis-imx6-parallel-rgb-overlay.dts)

Finally, once all overlay files have been enabled, reboot the board.

For more information about dtconf and device tree overlays, please, refer to Device Tree Overlays page.

Configure Other Displays with Torizon

To support a specific display we recommend using the device tree overlay to specify the exact display resolution and timings. We recommend you clone our repository that contains the device tree overlay samples and modify them according to your display resolution and timings. Make sure then to switch to the branch that matches the running kernel on your Torizon device.

On your development PC, clone the device-tree-overlays repository from Toradex:

$ git clone https://github.com/toradex/device-tree-overlays.git

Start the Developer Tools Container for TorizonCore on the computer on module.

Once it's running in interactive mode, create .dts file in /var folder to keep it persistant:

## vim test.dts

Check the datasheet of your display. Every manufacturer provides display timings in a slightly different way.

The Horizontal period must be the sum of hback_porch + hactive + hfront_porch + hsync-len and the Vertical period must be the sum of vback_porch + vactive + vfront_porch + vsync-len. Hsync-len and vsync-len parameters are not allowed to be zero sometimes.

Check our examples for a starting point. Copy the most appropriate in the test.dts you have created in a previous step:

LVDS display example: Capacitive Touch Display 10.1" LVDS Overlay

Parallel RGB display example: Capacitive Touch Display 7" Parallel Overlay

Other examples: Toradex Device Tree Overlays on GitHub

To deploy your customized Device Tree Overlay, check the instructions on the previous section.

Touch Screen Calibration

To calibrate your touch screen, please read the article Touch Screen Calibration (Torizon).

Torizon 4.0.0

Introduction

During the development cycle of a product with a GUI, you usually go through 3 phases when it comes to displays:

Evaluation: often, you will do a basic evaluation using a regular monitor over VGA/DVI-D/HDMI - or similar interfaces, if available. We provide an out-of-the-box experience, where you just have to plug in the monitor and power-on the hardware.

Proof of Concept: even with the advantages of cross-development tools and IDEs enabling a good experience for developing GUIs in a development computer, it is often common to make tests on the real end device. We sell touch screen displays that either deliver an out-of-the-box experience or a fairly easy configuration.

Prototype and Beyond: often, you want or need a custom display in your final product. The reasons are various: price, robustness, brightness, size, interface, EMI compliance, among others. Supporting a custom display is not an easy task for a beginner, especially if you use a display with bad documentation and Linux support. We document how to enable a custom display, but you must expect that some effort is associated with the process or, alternatively, hire a partner to do the integration for you.

Toradex tests and recommends the following displays to be used with its Computer on Modules (CoM) during early phases of development:

For these displays, Toradex provides an easy way to set-up and get running, by providing ready-to-use device tree overlays. It also means that you can tweak the existing overlays to support other displays as well. This article explains how to set up displays on Torizon.

This article complies to the Typographic Conventions for Torizon Documentation.

Configure Displays and Touch Controllers provided by Toradex with Torizon

See below the list of available Device Tree Overlays provided by Toradex and how to build, validate and enable it using Developer Tools Container.

Displays

Toradex provides Device Tree Overlays for the Displays available in the webshop.

Overlay Device
display-edt5.7-overlay.dts Enable the 5.7 inch display (EOL) for Colibri imx7, Apalis iMX6, and Colibri iMX6
display-edt7-overlay.dts Enable the 7 inch display (EOL) for Colibri imx7, Apalis iMX6, and Colibri iMX6
display-lt161010-overlay.dts Enable the 7 inch parallel display for Colibri iMX7, Apalis iMX6, and Colibri iMX6
apalis-imx8x-display-lt161010-overlay.dts Enable the 7 inch parallel display for Apalis iMX8X
colibri-imx8x-display-lt161010-overlay.dts Enable the 7 inch parallel display for Colibri iMX8X
display-lt170410-overlay.dts Enable the 10.1 inch lvds display for Apalis iMX6
apalis-imx8qm-display-lt170410-overlay.dts Enable the 10.1 inch lvds display for Apalis iMX8
apalis-imx8x-display-lt170410-overlay.dts Enable the 10.1 inch lvds display for Apalis iMX8X
apalis-imx6-lvds-overlay.dts Apalis iMX6Q requires a secondary overlay to enable the LVDS interface
apalis-imx6-parallel-rgb-overlay.dts Apalis iMX6Q requires a secondary overlay to enable the parallel RGB interface
colibri-imx8x-disable-parallel-rgb-overlay.dts Disable the parallel RGB interface on Colibri iMX8X

Touch controllers

Toradex provides Device Tree Overlays for the Touch Controllers for the Displays available in the webshop.

Overlay Device
apalis-imx6-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Apalis iMX6
apalis-imx8qm-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Apalis iMX8
apalis-imx8x-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Apalis iMX8X
colibri-imx6-aster-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Aster + Colibri iMX6
colibri-imx7-aster-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Aster + Colibri iMX7
colibri-imx6-eval-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Colibri EVB + Colibri iMX6
colibri-imx7-eval-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Colibri EVB + Colibri iMX7
colibri-imx8x-atmel-mxt-overlay.dts Enable the Atmel MXT touchscreen for the 7" and 10" display and Colibri iMX8X
apalis-imx8x-ad7879-overlay.dts Enable the resistive touch controller (AD7879) on the Apalis iMX8X module
colibri-imx8x-ad7879-overlay.dts Enable the resistive touch controller (AD7879) on the Colibri iMX8X module

Starting the Developer Tools Container

To to build, validate and enable overlays you need to use the dtconf command inside the Developer Tools Container.

Therefore, the first step is to start the Developer Tools Container.

Enable overlay

After selecting the corresponding Device Tree Overlays for your board, module, display and touch screen controllers from the table above, you need to activate it.

To enable the overlay for your display, you need to be in the interactive shell inside the Torizon Debian Dev Tools container on the Toradex Computer on Module (CoM), as explained earlier.

The following command will list Toradex provided overlays:

## dtconf status

Once you've identified the correct overlay for your setup you may use dtconf activate <file> -c device_tree_base.dtb to apply your capacitive touch overlay. You shall specify on which "base" device-tree you will apply your overlay with the flag "-c" followed by the *.dtb file of the given device-tree.

As an example, to enable enable the 7" parallel display for Apalis iMX8QM on an Apalis Evaluation Board (as a base device-tree), we use the following command:

## dtconf activate apalis-imx8qm-display-lt170410-overlay.dts -c fsl-imx8qm-apalis-eval.dtb

Attention: Replace the .dts file with the corresponding overlay file for your setup ( Carrier Board + Module + Display/Touch Controller model), as the table showed in the previous sections.

To enable the touchscreen for the touchscreen controller of Apalis iMX8QM:

## dtconf activate apalis-imx8qm-atmel-mxt-overlay.dts -c fsl-imx8qm-apalis-eval.dtb

Note: Note for Apalis iMX6: Apalis iMX6Q requires an additional overlay when enabling the LVDS interface (apalis-imx6-lvds-overlay.dts) or the parallel RGB interface (apalis-imx6-parallel-rgb-overlay.dts)

Finally, once all overlay files have been enabled, reboot the board.

For more information about dtconf and device tree overlays, please, refer to Device Tree Overlays page.

Configure Other Displays with Torizon

To support a specific display we recommend using the device tree overlay to specify the exact display resolution and timings. We recommend you clone our repository that contains the device tree overlay samples and modify them according to your display resolution and timings. Make sure then to switch to the branch that matches the running kernel on your Torizon device.

On your development PC, clone the device-tree-overlays repository from Toradex:

$ git clone https://github.com/toradex/device-tree-overlays.git

Start the Developer Tools Container for TorizonCore on the computer on module.

Once it's running in interactive mode, create .dts file in /var folder to keep it persistant:

## vim test.dts

Check the datasheet of your display. Every manufacturer provides display timings in a slightly different way.

The Horizontal period must be the sum of hback_porch + hactive + hfront_porch + hsync-len and the Vertical period must be the sum of vback_porch + vactive + vfront_porch + vsync-len. Hsync-len and vsync-len parameters are not allowed to be zero sometimes.

Check our examples for a starting point. Copy the most appropriate in the test.dts you have created in a previous step:

LVDS display example: Capacitive Touch Display 10.1" LVDS Overlay

Parallel RGB display example: Capacitive Touch Display 7" Parallel Overlay

Other examples: Toradex Device Tree Overlays on GitHub

To deploy your customized Device Tree Overlay, check the instructions on the previous section.

Touch Screen Calibration

To calibrate your touch screen, please read the article Touch Screen Calibration (Torizon).