Actually, if one of you can run the following command from a terminal with NO external monitor hooked up (just use the PiStation LCD only) and attach the dat file you get back, it's possible this can be fixed for everyone who has this case easily (assuming it was built correctly, lol).
The command would definitely work on Retropie, not sure about batocera or recalbox but worst that will happen is you don't get the output file I need.
EDIT: It might even be easier to just take a separate SD card and put Raspberry Pi OS on it just to do this test.
The command dumps the EDID data from the currently connected display (in this case, the PiStation LCD):
Code:
tvservice -d /tmp/edid.dat
Then you would have to get that 'edid.dat' file from the 'tmp' folder to your computer so you can attach it here.
If the LCD screen is programmed correctly, it will have an EDID, which is essentially both a unique identifier for the screen and optionally a set of specifications to tell a connected device what video and audio modes it supports.
We can then use the EDID (let's call it a serial number) of the PiStation LCD to add lines to the 'config64.txt' and 'config.txt' on your SD card to make your HDMI output *always* set to 1080p, unless it's connected to the serial number of the PiStation LCD, in which case it would use separate settings for 720p instead.
Since the HDMI port on the PiStation is a pass-thru, this all hinges on two things being done by retroflag:
1) The LCD has a unique serial number (EDID) programmed in to it
2) The Pass-thru connection being done 'properly' so that when a TV is connected, the LCD is 'disconnected' so that the only HDMI device visible to the Pi is the external TV/Monitor.
Essentially, this would be the code that you would add to the end of config.txt and/or config64.txt:
Code:
## Settings for Video Output (TV @ 1080p/60Hz)
hdmi_group=1
hdmi_mode=16
## Alternate Settings for Video Output (Monitor @ 1080p/60Hz)
## hdmi_group=2
## hdmi_mode=82
## hdmi_drive=2
[edid=LCD_EDID_NUMBER_GOES_HERE]
## PiStation LCD 720p
hdmi_group=2
hdmi_mode=85
hdmi_drive=2