KDE and XFCE4 has a program to adjust the screen brightness automatically in battery mode to a preset value. How can i set the same with Unity ( or Gnome3 )?
2 Answers
I found the solution:
If you have laptop-mode-tools installed
cat /sys/class/backlight/acpi_video0/brightness
cat /sys/class/backlight/acpi_video0/max_brightness
sudo -H gedit /etc/laptop-mode/conf.d/lcd-brightness.conf
Contents should be:
DEBUG=0
CONTROL_BRIGHTNESS=1
BATT_BRIGHTNESS_COMMAND="echo [min value]"
LM_AC_BRIGHTNESS_COMMAND="echo [max value]"
NOLM_AC_BRIGHTNESS_COMMAND="echo [normal value]"
BRIGHTNESS_OUTPUT="/sys/class/thermal/cooling_device0/cur_state"
Sources:
-
1Shouldn't the last line (
BRIGHTNESS_OUTPUT
) point to/sys/class/backlight/intel_backlight/brightness
(or similar) rather than the cooling device? Aug 24, 2016 at 8:47
- Download and install Cuttlefish
This tool helps in a lot of stimulus based reactions. - Install xbacklight
sudo apt-get install xbacklight
This tool helps in changing brightness via command line.
Now make a file(say dim) with following content:
#!/bin/bash
xbacklight -set 10
This command reduces your brightness to 10%.
Change the mode of the file:chmod +x dim
- Open the Cuttlefish application(using dash) and add a new reaction.Add a new stimulus Power Cable Unplugged from the Hardware category.
Next you need to set up the reaction.Go to Reaction>Applications>Start Application(Advanced Mode)
Now choose the executable as dim(file that we created earlier)
You may also want to increase the brightness when power is plugged again.For that follow the same steps except write xbacklight -set 100
and change stimulus to Power Cable Plugged In.
To make it work, you need to enable cuttlefish to start automatically. Go to edit/preferences (within cuttlefish) and enable start up .
-
This is a great guide man, I also managed to change the governor for my 4 threads CPU with
cpufreq-selector --cpu 0 -g powersave
EDIT: You probably have more then one core so add that comand multiplied by threads: 4 threads = 4 comands and change them in order--cpu 0
then next one--cpu 1
and continue to reach number of cores or on Intel CPU's, threads ;)– ZbunjeniNov 27, 2014 at 0:07 -
EDIT: To change the GOVERNOR without
sudo
you need gnome applets. You can get them via terminal command:sudo apt-get install gnome-applets
– ZbunjeniNov 28, 2014 at 13:02 -
1Cuttlefish is only released for 12.04. For newer releases of Ubuntu, use the other answer. Aug 24, 2016 at 8:45