I have a laptop running on Ubuntu 20.04 that only have one HDMI port and no thunderbolt one and I would like to add a third monitor to my configuration.
I thought about using a raspberry pi as a remote controller for the third screen and extend my laptop screen on it. What I mean by extend my screen is that I would like to have a real third screen, not a duplicate display of what is on my main laptop screen.
I tried to use xdmx and the following command:
startx -- /usr/bin/X11/Xdmx :1 -display 192.168.0.43:0 -display 192.168.0.24:0 -ignorebadfontpaths +xinerama
where 192.168.0.43 is my laptop adress and 192.168.0.24 is the raspberry one.
running this command I encounter the following error:
_XSERVTransSocketUNIXCreateListener: ...SocketCreateListener() failed
_XSERVTransMakeAllCOTSServerListeners: server already running
(EE)
Fatal server error:
(EE) Cannot establish any listening sockets - Make sure an X server isn't already running(EE)
Which is to be expected as I'm using the default desktop environment for Ubuntu 20.04.
My question is, what is the best way to obtain the desired result?
I think that it might be possible to create a new gnome-session so that a start up, using the command above or a similare one, it creates an xserver session and extend the screen to the raspberry pi considering that the pi is always up and running and if not it switches back to the default configuration, but I don't know how to do that.
I'm open to all suggestions and remarks but if possible I would like to keep the Gnome desktop as I'm use to it.
