Hi Toradex Team,
Display :
I’m using the Verdin AM62 SoM along with the Mallow Carrier Board, and I have an LVDS display panel that requires dual-channel LVDS
I noticed in the Mallow datasheet that there’s an LVDS Display Connector (X12) and a Capacitive Touch Connector (X13). It also mentions using JP1 to power the backlight.
However, I’m a bit confused:
- Does the Mallow Carrier Board support dual-channel LVDS output directly?
- If yes, could you guide me through the steps (e.g., pinout, Device Tree setup, video timings)?
- If not, do I need to use the Verdin LVDS Mezzanine board to enable dual-channel LVDS support?
Would really appreciate a bit of clarity on the hardware and software side.
Thanks in advance!
Uday
Hi, I’m the Toradex AI Assistant. The Toradex Support team will follow up with you shortly!
Did you like my answer?
Hello!
The Mallow Carrier Board, when paired with the Verdin AM62, supports LVDS display output through a DSI-to-LVDS bridge configuration. Here’s a concise overview:
-
DSI-to-LVDS Bridge Configuration:
- The Texas Instruments SN65DSI84-Q1 DSI to LVDS bridge can be set up for dual-channel LVDS output, supporting resolutions up to 1080p60 with 24-bit color in dual-channel mode. You can find more details in the Toradex documentation.
-
LVDS Interface Layout Requirements:
- Ensure proper length matching between the clock pair and data signals.
- The maximum frequency is contingent on the display resolution, with the frequency being seven times higher than the pixel clock in single-channel mode.
- Maintain a trace impedance of 100Ω ±15% differential and 55Ω ±15% single-ended.
-
Connectivity Considerations:
- The DSI to LVDS bridge requires configuration via I2C.
- Use the PWM_3_DSI pin (19) for display brightness control.
- The I2S_2_D_OUT can be utilized for enabling the display backlight.
Setting Up Dual-Channel LVDS:
-
Hardware Setup:
- Connect your display to the LVDS Display Connector (X12).
- Ensure JP1 is configured correctly for backlight power.
- If using touch functionality, connect the touch interface to X13. More information can be found in the Toradex community discussion.
-
Software Configuration:
- Apply the appropriate device tree overlay for your specific display configuration. For instance, a 10.1" LVDS display might use an overlay like “verdin-am62_panel-cap-touch-10inch-lvds_overlay.dtbo.”
I recommend reviewing the specific requirements of your LVDS display panel to ensure compatibility with these specifications.
If you have any further questions or need more details, feel free to ask!
Best regards,
Toradex AI Assistant
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Hi @Uday10122!
I saw you liked the AI’s answer. Were you able to solve your issue?
Best regards.
Lucas Azeituno
Hi @lucas_az.tx,
Thanks for your response — it answered a few of my questions, but not everything completely.
Could you please clarify the following:
- If dual-channel LVDS is supported on the Mallow Carrier Board with the Verdin AM62 SoM, could you guide me through the steps to enable it (e.g., pinout, Device Tree configuration, and video timing setup)?
- If not supported directly, do I need to use the Verdin LVDS Mezzanine board to enable dual-channel LVDS?
Just to give you context:
I have a dual-channel LVDS display, the Mallow Carrier Board, and a Verdin AM62 SoM.
I’ve successfully built a basic Yocto image — now I just need your guidance to get the dual-channel LVDS working.
Please give me complete steps to do that
Thanks and best regards,
Uday
Hi @Uday10122!
Mallow supports dual-channel LVDS directly (as you can verify on its datasheet, page 8). However, we don’t have an overlay for dual-channel using native LVDS, only with mezzanine (which can be used with Dahlia and the Development Board).
I would suggest using verdin-am62_mezzanine_panel-lvds-dual-channel-1080p_overlay.dts as a starting point and trying to reproduce it for native LVDS. You could use verdin-am62_panel-cap-touch-10inch-lvds_overlay.dts as an example of native LVDS.
The display timings should be described in the display datasheet. You can use the verdin-am62_panel-cap-touch-10inch-lvds_overlay.dts as an example, and, in addition, there is the panel-timing.yaml file, which explains more about the timings and how to calculate them.
That said, if you don’t have experience with writing an overlay or want it faster, please check our Partner Network where you can find a partner who will have the expertise to help you and accelerate the development.
Feel free to ask if you have any doubt.
Best regards.
Lucas Azeituno.
1 Like
Hi Lucas,
Thank you so much for your detailed and helpful response!
I appreciate the clarification regarding dual-channel LVDS support on the Mallow board and the suggestions for starting points with the device tree overlays. I’ll explore the verdin-am62_mezzanine_panel-lvds-dual-channel-1080p_overlay.dts and try adapting it for native LVDS using the verdin-am62_panel-cap-touch-10inch-lvds_overlay.dts as an example.
I’ll also refer to the panel-timing.yaml and my display’s datasheet to ensure the timings are accurate.
Thanks again for your support!
Best regards,
Uday
Hi @Uday10122!
I’m glad I could help you.
Best regards.
Lucas Azeituno
Hi @lucas_az.tx!
Here is my device tree overlay for the dual-channel LVDS setup along with the datasheet of the display I’m using.
DTS :
dual_channel_lvds.txt (3.7 KB)
Could you please check if the overlay looks correct for this setup?
Also, as per the datasheet (screenshot attached), the display requires a specific power-on sequence with signals like RESET_N, DISPLAY ON, and FCS. For now, I have left those pins unconnected.
Do I need to configure GPIOs in the device tree to drive these signals and follow the power-on sequence? Could this be the reason why my display is not turning on?
Thanks in advance for your help!
Best regards,
Uday
Display Datasheet :
Touchscreen TFT datasheet 1.pdf (1.8 MB)
Power on sequence :
Hi @Uday10122!
We always ask to open another topic for different issues (which I saw you already did). So I’ll close this and proceed with the support on the other topic.
Best regards.
