How to control brightness with i3
Low level manual brightness control
List your devices
ls /sys/class/backlight/
In my case
ls /sys/class/backlight/
amdgpu_bl1 asus_screenpad
or
ls /sys/class/backlight/
intel_backlight nvidia_0
You can check these brightness values
cat /sys/class/backlight/*/brightness
in relation to max_brightness
cat /sys/class/backlight/*/max_brightness
You can manually set brightness for selected device. For example.:
sudo nano /sys/class/backlight/amdgpu_bl1/brightness
Cli brightness control
but it’s not convenient. You can use brightnessctl instead.
yay -S brightnessctl
Then
brightnessctl s 5%+
or
brightnessctl s 5%+
more options can be found in help
brightnessctl --help
brightnessctl 0.5 - read and control device brightness.
Usage: brightnessctl [options] [operation] [value]
Options:
-l, --list list devices with available brightness controls.
-q, --quiet suppress output.
-p, --pretend do not perform write operations.
-m, --machine-readable produce machine-readable output.
-n, --min-value set minimum brightness, defaults to 1.
-e, --exponent[=K] changes percentage curve to exponential.
-s, --save save previous state in a temporary file.
-r, --restore restore previous saved state.
-h, --help print this help.
-d, --device=DEVICE specify device name (can be a wildcard).
-c, --class=CLASS specify device class.
-V, --version print version and exit.
Operations:
i, info get device info.
g, get get current brightness of the device.
m, max get maximum brightness of the device.
s, set VALUE set brightness of the device.
Valid values:
specific value Example: 500
percentage value Example: 50%
specific delta Example: 50- or +10
percentage delta Example: 50%- or +10%
Keybinding for brightness in i3
To bind it to i3 you can add to your config ~/.config/i3/config
bindsym XF86MonBrightnessDown exec brightnessctl s 5%-
bindsym XF86MonBrightnessUp exec brightnessctl s +5%
Automatic brightness control
If you are interested in automatic brightness control using camera as a sensor, you can check wluma