Using Touch Display 2, maybe an issue?

gregandnat

Hi there, (new here)

Been playing with my new Raspberry Pi Touch Display 2, works great on a desktop environment. I have also tried it on RetroPie using EmulationStation, but get only a black screen on the display (HDMI works great). Wondering if this is something simple, like I am missing something to drive the display.

Not necessarily looking to use the touch functions, just as a display connected via the ribbon cable. Am I missing something that may be an easy fix to get Retropie to recognize the display? Is this more of an EmulationStation question?

Thanks for any input.

Pi 3b+
PSU came with the kit, works for powering pi and display in desktop environment
RetroPie updated
USB Keyboard, mouse and controller, all work connected to HDMI display

mitu

Did you disable the HDMI output after connecting the display ? RetroPie works without a desktop environment on a Pi - are you booting to a command line only screen first ?
Can you run

/opt/retropie/supplementary/kmsxx/kmsprint-rp

and post the output ?

gregandnat

@mitu

Disable the HDMI output? Nothing in code, I just simply have it unplugged, assuming the Pi would not find it.

Tried the line of text you sent, just says 'no such file or directory' FYI, after Retropie launches, F4 to the command line for this, right? I also have a local PC that I usually SSH into, but can't do that on my Retropie install, maybe SSH is not enabled.

mitu

Tried the line of text you sent, just says 'no such file or directory' FYI, after Retropie launches, F4 to the command line for this, right?

Yes, that's right. Are you sure you're fully updated ? What's the exact RetroPie version you have installed and how did you install it ?

I also have a local PC that I usually SSH into, but can't do that on my Retropie install, maybe SSH is not enabled.

By default SSH is not enabled, look up in the docs how to enable it.

gregandnat

@mitu

1st, sorry, spoke too soon, I was enabling SSH as i wrote that last replay, that's all good, sorry to muddy the waters of the thread.

2nd, installed from https://retropie.org.uk/download/ just a few days ago. I believe version 4.8 for the pi 3b+. Went ahead and updated everything possible.

Seems to launch and run great using HDMI as output, just for some reason I get black screen on the touch display 2 when I try to use that only (I unplug the HDMI monitor and reboot). Pi is on, and I can now SSH into it.

I have been trying to find documentation on enabling the display output on the Pi board, all I ever seem to find are people who can't use HDMI, which is not my problem.

I appreciate you taking your time with responses.

mitu

@gregandnat said in Using Touch Display 2, maybe an issue?:

2nd, installed from https://retropie.org.uk/download/ just a few days ago. I believe version 4.8 for the pi 3b+. Went ahead and updated everything possible.

That's ok, but it still doesn't tell me the exact version. The command you said wasn't available should be installed if you have the latest RetroPie-Setup. However, since you're using the buster based image on the Pi3, the command may not help since - at that version - KMS/DRM is not used.

Can you try running:

tvservice -l
tvserver -s

and post the output ?

Seems to launch and run great using HDMI as output, just for some reason I get black screen on the touch display 2 when I try to use that only (I unplug the HDMI monitor and reboot). Pi is on, and I can now SSH into it.

I think you need to disable the HDMI ouput and let the DSI output to become 'primary', otherwise the system still outputs to HDMI. Just disconnecting the HDMI cable may not be enough and the tvservice -l command above may show you the status.

gregandnat

@mitu

Info below....

-With both HDMI and touchscreen attached.....
pi@retropie:~ $ tvservice -l
1 attached device(s), display ID's are :
Display Number 2, type HDMI 0

tvservice -s
pi@retropie:~ $ tvservice -s
state 0xa [HDMI DMT (39) RGB full 16:9], 1360x768 @ 60.00Hz, progressive

-With no HDMI attached, touchscreen only...

pi@retropie:~ $ tvservice -l
1 attached device(s), display ID's are :
Display Number 3, type Composite

pi@retropie:~ $ tvservice -s
state 0x40000 [NTSC 4:3], 720x480 @ 60.00Hz, interlaced

mitu

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).