====== Controlling the LCD Backlight ====== ===== Adjusting the LCD's Backlight Brightness ===== Adjust the brightness of the LCD using the [[https://manpages.debian.org/stable/brightnessctl/brightnessctl.1.en.html|brightnessctl]] utility. * Off: ''brightnessctl set 0%'' * 50% brightness: ''brightnessctl set 50%'' * 100% brightness: ''brightnessctl set 100%'' Or use the sysfs interface: * Off: sudo sh -c "echo 0 > /sys/class/backlight/backlight/brightness" * 50% brightness: sudo sh -c "echo 50 > /sys/class/backlight/backlight/brightness" * 100% brightness: sudo sh -c "echo 100 > /sys/class/backlight/backlight/brightness" ===== Toggle the LCD's backlight ===== To toggle the backlight on and off without adjusting the brightness, use the [[https://manpages.debian.org/trixie/wlopm/wlopm.1.en.html|wlopm]] command. If running from an SSH session, you may need to first run ''export WAYLAND_DISPLAY=wayland-0''. * Off: ''wlopm --off HDMI-A-1'' * On: ''wlopm --on HDMI-A-1'' Or, use the sysfs interface: * Off: sudo sh -c "echo 4 > /sys/class/backlight/backlight/bl_power" * On: sudo sh -c "echo 0 > /sys/class/backlight/backlight/bl_power"