A Cinnamon applet that lets you adjust brightness of external monitors via DDC/CI.
In order to function correctly this applet requires
It can be installed following these steps:
Install ddcutil and i2c-tools using:
sudo apt install ddcutil i2c-tools
To let ddcutil work without requiring root priviledges, the user must be part of the i2c group. Run the following command to add the current user to the i2c group.
sudo usermod -aG i2c $USER
After having executed the command, log out to apply the new configuration.
More information on how to install ddcutil can be found here in section "Tool 2".
You can check if ddcutil has been installed correctly and the monitor supports the DDC/CI protocol running: