Yrurtj

I'm trying to set custom screen bindings in i3WM and looking for a way to decrease/increase the brightness on button press. I've tried using the following:

xbacklight -dec10

xbacklight -set 70

xbacklight would work however it does not affect my HDMI connected monitor, no backlight apparently:

xrandr --verbose

HDMI-0 has no "Backlight" property unlike the laptop screen, the above code works fine on my laptop screen, however I want to reduce the brightness on all monitors.

Next I tried:

xrandr --output DP-0 --brightness 0.5

xrandr --output HMDI-0 --brightness 0.5

Which works! Well, for about 1 second then it defaults back. My question: is there any way I can get these changes to stick, at least until the next reboot?

PS - Running Debian GNU/Linux 8.5 | 4.5.0-0.bpo.1-amd64 | i3 4.8-2

PPS - I can easily set the i3 configuration and key bindings, no assistance needed with that part :)

You can use the following script found on doc.ubuntu-fr.org(based on xbacklight tool):

Create a new configuration file brightness under /usr/local/bin with the following contents:

#!/bin/bash



error="Usage: $0 up | $0 down"

xbl=`xbacklight`

limite1=2

limite2=10

limite3=40

limite4=100



if [ "$#" -eq 1 ]

    then

    if [ $1 = "up" ]

        then

        # Augmenter le rétroéclairage

        if [ $(echo "$xbl == $limite4"|bc) -eq 1 ]

                then

                echo "Rétroéclairage au maximum !"

                xbacklight = 100

            else

            if [ $(echo "$xbl < $limite2"|bc) -eq 1 ]

                    then

                    xbacklight +1

                 else

                if [ $(echo "$xbl < $limite3"|bc) -eq 1 ]

                        then

                        xbacklight +10

                    else

                    xbacklight +20

                fi

            fi

        fi

    elif [ $1 = "down" ]

        then

        # Diminuer le rétroéclairage

        if [ $(echo "$xbl < $limite1"|bc) -eq 1 ]

                then

                echo "Rétroéclairage au minimum !"

                xbacklight =1

            else

            if [ $(echo "$xbl < $limite2"|bc) -eq 1 ]

                    then

                    xbacklight -1

                else  

                if [ $(echo "$xbl < $limite3"|bc) -eq 1 ]

                        then

                        xbacklight -10

                    else

                    xbacklight -20

                fi

            fi

        fi

        else

        echo $error

    fi

    else

    echo $error

fi

exit

Make it executable:

sudo chmod +x /usr/local/bin/brightness

To increase the brightness , open the terminal and type:

brightness up

To decrease the brightness ,type:

brightness down

Are you using redshift?

I had your exact same issue and it was resolved by killing redshift.

killall redshift



xrandr --output HDMI-0 --brightness .5