Colibri iMX8X X2 connector: DSI-LVDS compatibility and I2C for both display and touch controller

Dear Toradex Community,

the Colibri iMX8X expose a MIPI DSI + I2C0 interface on X2 and I have two questions about it. The use case is about interconnecting a touch screen over custom adapter board:

  • is this X2 DSI interface compatible with LVDS displays? how can one check if there are compatible or non-compatible communication modes with a specific display model? Form a practical point of view, I suppose I have to select the right mode in device tree overlay.
  • is it possible to configure the X2 I2C port to communicate with both a touch controller and the display DDC/EDID at the same time? do you have already experience in doing this? Again, I think this must be configured in device tree.

Thank you for the feedbacks and best regards,

ldvp

Hello ldvp,

So LVDS is not like HDMI plug an play. There are always adaptations necessary towards the LVDS screen you intent to use. The X2 connector has a dual channel LVDS output.

The LVDS does not use DDC/EDID. you can use the I2C for the touch controller if you want.

The Colibri form factor does not feature a native LVDS interface on the SODIMM connector. However, the Colibri iMX8X is equipped with an additional FFC connector that hosts a dual-channel LVDS interface that can be configured to two independent single-channels. This LVDS FFC connector is not compatible with other Colibri modules. If compatibility with other modules is required, it is recommended to add an LVDS transmitter insteadfrom the parallel RGB LCD interface on the carrier board. Such a transmitter can be found on the Colibri Evaluation Board and is described in the Colibri Carrier Board Design Guide.

Please check the following tables in this dokument.

4.42 Mipi
5.6.2
table 5-19

Best Regrads,

Matthias