Seems to me that even with the HDMI port disconnected, the Pi thinks that a composite display is connected.
Sorry, but I have no idea how you can convince the OS that you're using a DSI display and whether that will work without X11/Wayland on the buster. I noticed in the RPI docs that there's a KMS type overlay for the display which would make it work without X11/Wayland (as required by RetroPie), but I'm not sure whether that would work without installing the lateste RaspiOS (which is based on Debian 12 bookworm).

@josdelsan said in SPI connection driver alternatives for ILI9341V display?:

Before I go back to RPI forum, I would like to know where I can read more about how emulationstation GUI is loaded so I can provide some context, otherwise I will be sent back here again.

You can replace EmulationStation with any SDL/non-SDL app that uses a GLES/OpenGL context and you have the same result (i.e. RetroArch or Mame). There's nothing special about EmulationStation and you can achieve the same result with any of GL test applications from the libsdl2-tests, like testgl2 or testgles2 (from /usr/libexec/installed-tests/SDL2/).

Use the screen configuration utility and make the 2nd HDMI port the primary screen.
Note that RetroPie is not supported on a desktop environment or on TwisterOS.

@sleve_mcdichael I've done this when I first started using overlays. I've found it works with some, not with others. Depends on where the overlay is from.. and if I decide to zoom in or zoom it out a little. I try to set my overlays/bezels to the best possible screen size for the system, and that's not always the stock size.

I eventually switched to manually setting the size and it seems to work really well . Once I'm happy with the bezel, I don't change it anyway.

BTW... Your description is probably the best I've read on the subject. Thanks for sharing it.

@exarkuniv Ok now I feel extremely stupid for not thinking about this before. But because I'm probably not the only one, I figured I'd post this info in case others run into the same thing. After wasting more than half a day trying different HDMI configurations and editing the config file a million times, I realized that by plugging in HDMI 1 into the lcd controller and using HDMI 0 as the output source for a bigger TV, the pi will always check HDMI 0 first for signal and if it doesn't find one, then it goes to HDMI 1. So in other words, no need for an HDMI switch or splitter. Man I feel so stupid but at least the problem is solved now.

@tmoe01 said in Dip Switch help:

Now my task to tackle will be figuring out how to flip the screen for player 2.

this part might involve dipswitches, other clones, or maybe the service menu. look for options to enable cocktail mode, etc.

@tyon2006 said in Using HD LCD with Retropie and RPi4:

Makes sense. Any thoughts on retroarch/emulation station supporting these super high resolutions?

If you add a custom hdmi_mode and it's recognized by the Pi4, it should be used automatically.

On the Pi3, I couldnt even get it to boot up all the way

That's normal, since the Pi3 didn't support these large resolutions.

I did a power cycle/reset on my TV which seems to have fixed the issue. Im guessing my TV may have done an automatic update overnight which may have caused the issue in the first place.