Unless you're running under X/Desktop/Wayland, there's no control over the which display comes 'first' at runtime. You can use config.txt to enable/disable the LCD (is it a DSI display ?) or HDMI, but that requires a reboot.

You can ask the vendor for support, using the current RetroPie image. Another option is to check whether a current RaspiOS (Bookworm) supports the screen and works better to make the LCD primary, a current release means you can ask for help in the RPI forums. Using the current RaspiOS you can use a manual installation of RetroPie, which is still in beta for this OS release, but should work for most things.

The cmdline.txt options in the linked topic will only rotate the console terminal, not the entire display. To rotate also EmulationStation's screen or the emulator video output, you need additional configurations - some details are in this topic.

Do you have the 7″ touch display ? You probably had to configure the Pi to use the DSI output my modifying the bootloader configuration (the config.txt file on the boot) partition. To switch back to HDMI, you'll need to remove or comment the lines that enable and configure the LCD.
There might be a way to enable the LCD display only of HDMI is not detected through the use of conditional filters in config.txt, but you'll have to experiment and see if that's possible. If the LCD pannel cannot be detected at boot by the bootloader, then conditionally enabling/disabling it might not work.

@mitu i used the git command and i used cp in the /boot/overlays as root

The project at https://github.com/swkim01/waveshare-dtoverlays offers only the new driver setup for the display, it doesn't provide any scripts.

can you elaborate?

Sure. You want to handle 2 video configurations - output to HDMI (which is default) and via the LCD. Save the default config.txt in /boot/ as /boot/config-hdmi.txt. Install and configure the LCD drivers (modify the config.txt) accordingly, make sure it works, then copy the config.txt to /boot/config-waveshare.txt.

Create 2 scripts in /home/pi/RetroPie/retropiemenu

hdmi.sh, containing #!/usr/bin/env bash cp -f /boot/config-hdmi.txt /boot/config.txt lcd.sh, containing #!/usr/bin/env bash cp -f /boot/config-waveshare.txt /boot/config.txt make the scripts executable by running chmod +x /home/pi/RetroPie/retropiemenu/hdmi.sh chmod +x /home/pi/RetroPie/retropiemenu/lcd.sh

Now, when starting EmulationStation, you'll have 2 new entries in the RetroPie system - HDMI and LCD, executing one of them will switch the video output configuration. After running one of the entries, you'll have to reboot to activate the new configuration.

@mitu Spot on mate, I've seen a few of them for reasonable prices as well! Thank you

@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.

@mitu said in Tried to prioritize HDMI output over LCD now my LCD doesn't work at all:

@ns27 Revert the change you've done and see if it fixes it.

ok ill try that

Oh that's interesting. I'm using the default driver, I guess rotation did not work for emulationstation when it was done through config.txt. However adding the --screenrotate, it definitely worked.

I'm also looking at the script they provided to set it upt.
https://github.com/goodtft/LCD-show/blob/master/MPI4008-show

sudo echo "dtoverlay=ads7846,cs=1,penirq=25,penirq_pull=2,speed=50000,keep_vref_on=0,swapxy=0,pmax=255,xohms=150,xmin=200,xmax=3900,ymin=200,ymax=3900" >> ./boot/config.txt.bak

Guess I need to be using the ads7846 driver instead of the default one. For now I'm just happy it worked. Thanks.

Worked perfectly. Thank you so much!

@vinz3nt said in iPad 2 LCD + controller:

Had anyone tried these before? The LCD with audio board option on AliExpress?

€ 20,82 13%OFF | 9.7"inch 1024*768 HD screen display 4:3 LCD Controller LP097X02 LTN097XL01 monitor driver board HDMI VGA 2AV for Raspberry Pi

https://s.click.aliexpress.com/e/AjrY3Mz

Would be fairly cheap, good quality and the right aspect ratio (or close at least)

I'm a bit hesitant to buy one so I was wondering if there's some that has experience with this one.

Or maybe someone has better option? I want to build a small arcade system.

Thanks for any help

I've not used that particular board and/or screen before, but I have ordered a similar configuration from aliexpress before (although I bought a much lower priced and lower resolution allwinner screen) and their service was absolutely fantastic. despite it taking nearly 2 weeks to arrive I got full tracking and I'd say in that sense it was better than ordering from the UK since you knew exactly where the item was at all times. It was well packaged and I was up and running within minutes of receiving my parcel (although I did have to make some changes to my config file before it would boot, due to the strange resolution I had to set it to). I'm dubious about it saying HD but then saying VGA in the same description. I didn't know ipad screen resolutions were so low and 4:3? But you know all said and done it's gonna be a great quality screen for what you need as most games run at that aspect ratio and for the price you're normally looking at double that for a decent screen, plus you get the driver board too so it should work straight out of the box.

@cyperghost You mean like this?

SFC Pi