Screen priority

Breeliance

Dear retropie Community,
I'm reaching out to you to get some help with my retropie Project and maybe should make clear that I have no expertise in IT whatsoever, that's why a really detailed answer would be highly appreciated.

So currently I have a Raspberry 4 Model B set up to Run retropie, everything runs fine.
But I plan on changing the current casing to a 7" Touchscreen - Wimaxit M728 (connected via Adapter to one of the HDMI ports)

And that is what leads me to the question: how can I configure the pi so that it just uses the 2nd HDMI Channel once it's connected to another Monitor? (The "Main" Screen should not be used at all if both are in use, it's supposed to be a purely portable solution).
I imagine I could simply remove the HDMI adapter when plugging it into a TV but I'm hoping for a more elegant solution.

Thanks in advance <3

Breeliance

@mitu Sry for simply tagging you but you seem to be kind of good with such stuff :(
Still didn't figure it out and thought you may be able to help me <3

mitu

@Breeliance I'm afraid I'm not familiar with this kind of setup and don't have any advice.

Do note that switching screens or choosing which screen is used (when having multiple monitors connected) doesn't work without X11/Wayland, but RetroPie doesn't support or use X11/Wayland for Raspberry Pi.

Breeliance

@mitu Thanks for your fast reply

Wouldn't there be a way to mirror the output so both Screen show the same picture at least :x ?

mitu

@Breeliance said in Screen priority:

Wouldn't there be a way to mirror the output so both Screen show the same picture at least :x ?

As I said, you need to run in a desktop environment, from which you can start a screen configuration utility and set-up the multi-monitor configuration (mirroring, extension, etc.).