01-19-2024, 10:17 PM
(01-19-2024, 05:28 PM)TheOldPresbyope Wrote: @Facel
Is there not a full version (e.g., with desktop) Raspberry Pi OS i(RaspiOS) image you can boot on this Allo USB Bridge?
=> Yes I can load a lite version (32 or 64 bit) without desktop and tell you the result in my next post
True, RaspiOS has close to a pure debian root filesystem but it has its own kernel, drivers, and tweaks.
I assume you booted a full version of debian rather than a lite version---you do have a desktop displayed, right? I'm going to assume it's running either pure X11 or X11 under Wayland and not pure Wayland.
=> I have booted with the Legacy 64 bit version, with security update and desktop environnment
What does debian say the screen resolution is (width-in-pixels by heighth-in-pixels) when you say "the display is ok"?
=> "The display is ok" means that the display is NOT flattened horizontally, ie text on the extreme left and extreme right of the screen is totally displayed
Please find below the result of the Legacy 64 bit version with desktop
DISPLAY=:0 xrandr
Screen 0: minimum 320 x 200, current 1280 x 800, maximum 2048 x 2048
HDMI-1 connected primary 1280x800+0+0 (normal left inverted right x axis y axis) 261mm x 163mm
1280x800 60.01*+
1920x1080 60.00 60.00 59.94
1600x1200 60.00
1680x1050 59.88
1280x1024 75.02 60.02
1440x900 59.90
1280x720 60.00 59.94
1024x768 75.03 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
720x480 60.00 59.94
640x480 75.00 72.81 66.67 60.00 59.94
720x400 70.08
For example:
- moOde 8.3.7 on a Pi3B+ driving an official 7" LCD touchscreen via DSI (bullseye release of underlying debian).
Code:pi@home:~ $ DISPLAY=:0 xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 800 x 480, current 800 x 480, maximum 800 x 480
default connected 800x480+0+0 0mm x 0mm
800x480 0.00*
- current RaspiOS on a PI400 driving my desktop monitor via HDMI (bookworm release of underlying debian)
Code:kreed@pi400:~ $ DISPLAY=:0 xrandr
Screen 0: minimum 16 x 16, current 1920 x 1080, maximum 32767 x 32767
XWAYLAND4 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 510mm x 290mm
1920x1080 59.96*+
1440x1080 59.99
1400x1050 59.98
1280x1024 59.89
1280x960 59.94
1152x864 59.96
1024x768 59.92
800x600 59.86
640x480 59.38
320x240 59.52
1680x1050 59.95
1440x900 59.89
1280x800 59.81
720x480 59.71
640x400 59.95
320x200 58.96
1600x900 59.95
1368x768 59.88
1280x720 59.86
1024x576 59.90
864x486 59.92
720x400 59.55
640x350 59.77
Extended Display Identification Data (EDID) is the metadata standard used by an HDMI interface in returning information about a connected display. That's how RaspiOS knows the resolutions of the desktop monitor I used in the above example.
RaspiOS can ignore this returned EDID information, substituting a set of EDID data of its own. If nothing else, we can try to fake it 'til we make it. with your touch screen display.
[aside]
We'll never know what the native resolution of your physical LCD panel is. You've got a blackbox HDMI (digiral) to VGA (analog) converter which is driving the VGA input port of the blackbox display interface which converts the VGA (analog) signals into the specific digital signals needed by the input lines of the physical LCD panel. By blackbox, I mean we have no idea what's inside.
=> according to my screen doc, the native resolution version is 1280 x 800
[aside #2]
RaspiOS is transitioning to Wayland. For the time being we're ok, but in future moOde will be more dependent on Wayland, not X11. Different tricks may have to be played.
Ain't life grand?
Regards,
Kent
Thanks for your help, You can find my answers above in blue color
