You can use xbacklight app to set the brightness for you. You can then add it to the StartupApps.
Just install it:
sudo apt-get install xbacklight
And then run:
xbacklight -set 70 where 70 is the percent for the brightness.
I tried several things to auto adjust my brightness settings and stop changing it every time the PC is rebooted. So this is the only way it worked:
- sudo gedit /etc/rc.local
- cat /sys/class/backlight/acpi_video0/max_brightness
- the command will show you what is the maximum level of brightness you have
- echo xx > /sys/class/backlight/acpi_video0/brightness #Add this line in the rc.local file above the “exit 0” statement. xx is a number of the brightness you have.
- Save and reboot and no more brightness adjusting 🙂
Answer taken from here:
For the 3.16 kernel I had also to edit the grub to include the native backlight so the rc.local config would work:
sudo nano /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" to GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video.use_native_backlight=1"