@aprilmaccydee

Thanks for this example! I got the Waveshare Magic Mirror a few days ago and was looking for a solution to dim the backlight.

I’m using xscreensaver to blank the screen after 2 minutes and used the ddcutil command to dim the backlight.

Here is the script I’m using:

#!/bin/sh
process() {
        while read line; do
                case "$line" in
                        UNBLANK*)
                                sudo ddcutil setvcp 10  100
                        ;;
                        BLANK*)
                                sudo ddcutil setvcp 10  1
                        ;;
                esac
        done
}

xscreensaver-command -watch | process   

I use xscreensaver-command -watch to get the state changes, see https://www.jwz.org/xscreensaver/man3.html