This repository contains a very simple script to control the brightness of the ASUS Screenpad Plus on the ASUS ZenBook Duo laptops.

To install and use it:

1. Install the patched kernel module using dkms, as described here (for kernel 5.4)
2. It is important that you have added the line sudo chmod a+w '/sys/class/leds/asus::screenpad/brightness' to your /etc/rc.local file so that you can use the script without sudo.
3. Download the script to your /usr/bin folder and make it executable:

   cd /usr/bin
   sudo wget 'https://raw.githubusercontent.com/Plippo/screenpad-tools/master/screenpad'
   sudo chmod a+x screenpad
   

   Now it is ready to use.
4. To control the brightness of your ScreenPad Plus, simply call:
   • screenpad X where X is a value between 1 and 9 to change the brightness (1 is darkest, 9 is brightest)
   • screenpad 0 to turn the ScreenPad off (to turn it back on, just set the brightness using the command above)
   • screenpad up to increase the brightness one step
   • screenpad down to decrease the brightness one step
   • screenpad toggle to toggle the ScreenPad between on and off.
5. To facilitate using the script, you can define shortcut keys using the means of your desktop environment. E.g. GNOME has a tool to set shortcuts under Settings > Shortcuts. Add a new command and set the shortcut you like. For instance, I set Windows+F4 to /usr/bin/screenpad down to decrease the brightness and Windows+F5 to /usr/bin/screenpad up to increase it. So just as you control the brightness of the main screen using Fn+F4/F5 you can now control the brightness of the ScreenPad using Windows+F4/F5. I also set the key next to the On/Off key to screenpad toggle so I can turn it on and off using that key, just like under windows.