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wchouser3

Member

From: Indiana USA

Registered: 2013-08-13

Posts: 161

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how do I get backlight to dim automatically when switching to battery

I got an HP with a Radeon driver (open-source) I use "Light" (from the AUR) to control the screen brightness. Is there a udev rule or something i can write to change the backlight depending on ACPI events, specifically the power being plugged and unplugged? I don't want to install a bulky power manager.

Thanks

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If you can't be helpful, don't say anything at all. Fair enough?

halocaridina

Member

From: US

Registered: 2014-07-21

Posts: 77

Re: how do I get backlight to dim automatically when switching to battery

I use this combination of rules in /etc/udev/rules.d.

98-backlight.rules

# Adjust screen brightness according to power state
# 1st rule for when on AC
ACTION=="change", SUBSYSTEM=="power_supply", ATTR{type}=="Mains", ATTR{online}=="1", ENV{DISPLAY}=":0", ENV{XAUTHORITY}="/home/YOUR_USERNAME/.Xauthority", RUN+="/usr/bin/xbacklight -set 75"
# 2nd rule for when on battery
ACTION=="change", SUBSYSTEM=="power_supply", ATTR{type}=="Mains", ATTR{online}=="0", ENV{DISPLAY}=":0", ENV{XAUTHORITY}="/home/YOUR_USERNAME/.Xauthority", RUN+="/usr/bin/xbacklight -set 35"

99-backlight_notification.rules

# Notification sound when screen brightness is changed according to power state
# When unplugging
ACTION=="change", SUBSYSTEM=="power_supply", ATTR{type}=="Mains", ATTR{online}=="0", ENV{DISPLAY}=":0", ENV{XAUTHORITY}="/home/YOUR_USERNAME/.Xauthority" RUN+="/usr/local/bin/brightness_notification.sh"
# When plugging in
ACTION=="change", SUBSYSTEM=="power_supply", ATTR{type}=="Mains", ATTR{online}=="1", ENV{DISPLAY}=":0", ENV{XAUTHORITY}="/home/YOUR_USERNAME/.Xauthority" RUN+="/usr/local/bin/brightness_notification.sh"

/usr/local/bin/brightness_notification.sh

#!/bin/bash

/usr/bin/aplay /home/YOUR_USERNAME/.i3/sounds/Click1.wav

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