Info:

I think the Hotkey Fn+F6 works since some time If you install the latest Ubuntu updates.

Rotate the screen and touchscreen input 180 degrees

create the script /usr/local/bin/rotate-screen.sh

(I enhanced that script there at gist so it rotates 90° also)

#!/bin/bash

# This script rotates the screen and touchscreen input 180 degrees, disables the touchpad, and enables the virtual keyboard

# And rotates screen back if the touchpad was disabled



isEnabled=$(xinput --list-props 'SynPS/2 Synaptics TouchPad' | awk '/Device Enabled/{print $NF}')



if [ $isEnabled == 1 ] 

then

    echo "Screen is turned upside down"

    xrandr -o inverted

    xinput set-prop 'ELAN Touchscreen' 'Coordinate Transformation Matrix' -1 0 1 0 -1 1 0 0 1

    xinput disable 'SynPS/2 Synaptics TouchPad'

    # Remove hashtag below if you want pop-up the virtual keyboard  

    # onboard &

else

    echo "Screen is turned back to normal"

    xrandr -o normal

    xinput set-prop 'ELAN Touchscreen' 'Coordinate Transformation Matrix' 1 0 0 0 1 0 0 0 1

    xinput enable 'SynPS/2 Synaptics TouchPad'

    # killall onboard 

fi

and give it executable rights:

sudo chmod +x /usr/local/bin/rotate-screen.sh

then

1.

create *.desktop file in /usr/share/applications/

gksudo gedit /usr/share/applications/rotate-screen.desktop

2.

Paste below text:

[Desktop Entry]

Type=Application

Terminal=false

Icon=/usr/share/icons/hicolor/48x48/apps/un-reboot.png

Name=rotate-screen

Exec=/usr/local/bin/rotate-screen.sh

Categories=Utility;

Then run the script via the Unity launcher startmenu (type "rotate-screen")

Source:

https://askubuntu.com/a/446125/34298