Dual screen shows in Extended mode all time

[McLund]

Hi.

I have a new Raspberry Pi4B updated to last firmware (rpi-update).

The FullPage OS is fullpageos-buster-lite-0.11.0.

To this Pi4 is two new HDMI Philips monitors connected.

The /boot/config.txt file is unchanged.

The problem is that at the screen shows in Extended mode all time. I want to show same screen on both monitors in duplicate mode.

When the computer boot up, the boot text will be in duplicate mode.

OBS. If i run Raspberry´s original raspbian-buster-full desktopversion the screen work´s perfect in duplicate mode.

Is there maybe anyone who can help me to setup an working /boot/config.txt file?

Thank´s for all help! ;-)

Best regard´s,
McLund

[chriswong11]

Try this:
sudo nano /etc/lightdm/lightdm.conf

Under [Seat:*]
Add: display-setup-script=xrandr --output HDMI-2 --same-as HDMI-1

Hope this helps for now.

[McLund]

Hi Chris. Thank you for your help. I have now tested your solution but it will not work. The two screens shows still in Extended mode as before. Best regard´s McLund

[guysoft]

@chriswong11 Should we add that to the distro? I'd like two screens, but having a mirror is a good start.

[asdf1nit]

@guysoft This fits my needs perfectly. I have some some plans to add 2 signage displays back to back and wanted a mirrored setup. If this could be added as a Config option in fullpageOS it would be great. If you would rather go with a module option I'm thinking about adding it to the admin toolkit as an option, along with screen blanking/display options.

[Vetal7979]

Try this: sudo nano /etc/lightdm/lightdm.conf

Under [Seat:*] Add: display-setup-script=xrandr --output HDMI-2 --same-as HDMI-1

Hope this helps for now.

I have HDMI monitor and LCD DPI screen 7" ( https://www.waveshare.com/wiki/7inch_LCD_for_Pi )
can it works in duplicate mode?
(RPI 4B, FullPageOS stable ver)

[Vetal7979]

xrandr command out this:
Screen 0: minimum 320 x 200, current 1600 x 900, maximum 7680 x 7680
HDMI-1 connected primary 1600x900+0+0 (normal left inverted right x axis y axis) 443mm x 249mm
1600x900 60.00*+
1440x900 74.98 59.89
1280x800 74.93 59.81
1152x864 75.00
1024x768 75.03 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
640x480 75.00 72.81 66.67 59.94
720x400 70.08
HDMI-2 disconnected (normal left inverted right x axis y axis)
DPI-1 connected 1024x600+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
1024x600 60.00*+

in ./pi/home/scripts/start_gui.sh before string /home/scripts/run_onepageos i add:
xrandr --output DPI-1 --mode 1024x600 --same-as HDMI-1

screen begin work in duplicate mode, but resolution on DPI-1 is not 1024x600
(may be 1600x900)

[ndbroadbent]

I'm using the nightly release of FullPageOS on a Raspberry Pi 4B, and I'm trying to figure out how to get extended display working on two monitors. I can see the logs and splash screen on both screens when the pi boots, but the second screen goes blank once chromium starts. So far I've tried adding xrandr --output HDMI-2 --same-as HDMI-1 to ~/scripts/start_gui, and I've also tried adding display-setup-script=xrandr --output HDMI-2 --same-as HDMI-1 to the [Seat:*] section in /etc/lightdm/lightdm.conf. Neither of those seem to make any difference.

The only other change I've made to my setup is setting DISPLAY_ORIENTATION=right in ~/scripts/start_gui for my vertical monitor.

---

Ahhhhh, it looks like you can only call xrandr once. I updated the original call in the start_gui script:

if [[ "${DISPLAY_ORIENTATION}" != 'normal' ]];
then
  xrandr --orientation ${DISPLAY_ORIENTATION} --output "HDMI-1" --left-of "HDMI-2"
fi

This is getting closer! Now I have an extended screen across both monitors, but I lost the vertical orientation.

---

Figured it out!

xrandr --output HDMI-1 --rotate ${DISPLAY_ORIENTATION} --output HDMI-2 --rotate ${DISPLAY_ORIENTATION} --above HDMI-1

You have to use the --rotate flag instead of --orientation when specifying multiple --output arguments.