README

• Control monitor with ddcutil extension
  • Set-up
  • Testing / troubleshooting
  • Configuration

Control monitor with ddcutil extension

This extension allows you to control some (external) monitor features. It is only a wrapper for the program ddcutil: http://www.ddcutil.com/

If it works, then a slider for the brightness is added to the GNOME quick-settings:

The sliders with the monitor icon on the right side control your monitor brightness / volume

Set-up

1. You need to have ddcutil installed
2. ddcutil needs to be working and your user needs to have the necessary permissions to use it

• Depending on your Linux distribution, this can be a quite convoluted process.
• The newest version of ddcutil, if packaged properly, should just work, so try it first.
• You may need to reboot your Linux after installing ddcutil for the first time.

The official instructions are here:

• http://www.ddcutil.com/install_config_main/

Here are some further links you can check (no warranty):

• https://wiki.archlinux.org/title/Backlight#External_monitors
• https://github.com/daitj/gnome-display-brightness-ddcutil#setup-ddcutil

Testing / troubleshooting

1. Test if ddcutil works. Open a terminal emulator and run this command:

   ddcutil getvcp 0x10

   This shall return the current brightness of your monitor, for example like this:

   VCP code 0x10 (Luminosity): current value = 29, max value = 100

   If this does not work, you need to fix the error first. Try following the links in the set-up chapter above.

   Note Not all monitors support DDC. If yours does not, you cannot use this extension.

2. Open journalctl to see your system log. Open a terminal and run this command:

   journalctl -b -0 -g monitor-brightness-volume@ailin.nemui

   If you see the message

   Searching for DDC/I2C monitors

   The extension was loaded. If you also see the message

   Warning: no monitors found on I2C, extension sleeping

   check again if ddcutil works.

Configuration

A configuration editor is planned for the next version. Until then, you can hide the volume if you do not need it with the following command:

GSETTINGS_SCHEMA_DIR=$HOME/.local/share/gnome-shell/extensions/monitor-brightness-volume@ailin.nemui/schemas::::: dconf write /org/gnome/shell/extensions/monitor-brightness-volume/show-volume false

See here for changing keyboard short-cuts