Advanced users • Re: Combine HDMI and DSI displays into one large virtual screen

Hi all,

I have a Raspberry Pi 4 with two touchscreens attached:
A) 1920*720 HDMI/USB
B) 1280*800 DSI

Thanks to 6by9's incredible work, I've managed to get both screens to work, including correct touch functionality in various rotations. Yay!

Now comes my next goal: "Combining" the two displays, so that the OS sees one large display, and so that one application can run in fullscreen mode on both displays.

The first question is: Is that even possible? Since the displays have different resolutions, just "gluing them together" would result in a non-rectangular viewport... and I can't imagine that working easily. I wouldn't care though, if the "combined" viewport was for example 3200*800 and some pixels would be "lost" where Display A is smaller.

And the second question is, of course, how would I go about configuring this? I've read some things about xrandr, but I also found some posts saying that the legacy graphics driver had to be activated for this. That is not a possibility for me, since I need vc4-kms-v3d for the DSI display to work.

Thanks for any input!

Statistics: Posted by aBUGSworstnightmare — Tue Feb 20, 2024 5:07 pm