Ubuntu – Brightness in ubuntu 12.04

12.04brightnesslaptop

Well this is a common problem as i have seen through my google searches but i didn't manage to find any satisfactory solution so far. I got my laptop recently which came with windows 8 pre-installed.I decided to install ubuntu (i had it in my former laptop) but the main problem is that when ubuntu starts the brightness is 0 be default(my laptop has a backlit button too). I can use the Fn buttons to change back to what i want but i wondered if there is a solution after all. The only solutions i found so far set the brightness in a default value which fix the low brightness problem after the start up but i cant control the brightness with the fn buttons afterwards. If anyone has a solution please share. Thanks in advance.
ps my laptop is Lenovo G510

Best Answer

Well this might be a workaround

Edit you rc.local file which will run on each startup,

sudo gedit /etc/rc.local

to write there something like,

echo 100 > /sys/class/backlight/intel_backlight/brightness

or 

echo 100 > /sys/class/backlight/acpi_video0/brightness

depending on what defines your system brightness.

you can find out which brightness value is best for you by looking in the "actual_brightness" file. Then change the 100 for that number.