OLED Linux

oled-linux.sh will watch the backlight changes in /sys/class/backlight/intel_backlight and apply changes over there to OLED screens

Features

Brightness Change on OLED screens on Linux (main point of the repository)
Smooth Brightness Control (changes in brightness will be applied gradually instead of just jumping to the new brightness)
Night Light Support (with or without geolocation and with smooth cycle changes)
Multiple Displays Support
Works directly on X, is not tightly coupled to any desktop environment, so it should work well in almost any circumstance

Dependencies

inotifywait - used for watching for file changes with as little CPU usage as possible
sunwait - (optional) used for monitoring day/night cycle for night light feature
geoclue2 - (optional) used for getting current location for day/night cycle for night light feature. Optional because location can be set manually

Installation (Ubuntu)

sudo apt install inotify-tools

# For redshift (Night Light) support, also add
sudo apt install geoclue2.0 geoclue-2-demo
snap install sunwait

Clone the repository and test the script by running it. To automatically run it at startup you should add it to your startup applications.

Night Light

If night light is enabled in oled-linux.sh, all brightness changes are applied using redshift, which allows for Night Light support. If Night Light is disabled in the config, brightness changes will be applied with xrandr.

Default values for night filter:
DAY = 6500 (default, unchanged display) NIGHT = 3500 (default night-filter value)

You can change the night filter value to whatever you want by modifying oled-linux.sh (see the configuration options below). You can also adjust the daylight value so that you can add a filter during the day as well.

Night Light can work without geolocation, in which case you have to specify your location in the configuration section using the following format: LATITUDE_DEGREES[N/S] LONGITUDE_DEGREES[E/W].

Configuration

Configuration can be set in the oled-linux.conf file.

##
# Backlight driver file location
backlight_dir="/sys/class/backlight/intel_backlight/"

##
# OLED Display Name
# If not set the script will attempt to guess it.
# Use `xrandr --current | grep " connected"` to get a list of all connected
# displays. Examples are: e-DP1, eDP-1, eDP-1-1
oled_screen=""

##
# Brightness step size
# How quickly to change the screen brightness?
# Values between 1(immediately) to 500(it takes about 10 seconds for the whole range) make sense.
# Default is 10.
# Can be configured at runtime.
brightness_step_size_factor=10

##
# Redshift (Night Light) functionality
# If enabled the script will also change the color temperature of the display.
# Can be configured at runtime.
use_redshift=true

##
# Color temperature during the day
# Can be configured at runtime.
daylight_temperature=6500

##
# Color temperature at night
# Can be configured at runtime.
night_temperature=4800

##
# Color temperature step
# how much to change the temperature of the night light on one frame
# the lower the value, the longer it takes to transition to a new redshift temperature
# has to be an integer value, no fractional values are allowed
# Can be configured at runtime.
redshift_step_size=50

##
# Location
# The script will use geoclue to automatically get your location. If you would
# like to provide it manually instead use the following format:
# location="42.6604944N 24.7494263E"
location=""

Performance

oled-linux.sh uses inotifywait to watch for changes in:

file-pipes/day-night.txt
/sys/class/backlight/intel_backlight

and it will only run when there are changes to apply.

Internally the script uses three services:

The first checks for location information using geoclue2 every 30 minutes and writes that info to file-pipes/current-location.sh.
The second watches for changes in file-pipes/current-location.sh and if the location changed, writes the new location to file-pipes/location.txt.
The third writes DAY or NIGHT to file-pipes/current-location.sh whenever it becomes day/night outside according to location data and when the location data is changed. Whenever these things are not happening, this script will sleep.

Troubleshooting

If you are running with geolocation enabled, it might take a few minutes for location data to become available. In most cases, location data is only available on active internet connection.

oled-linux may controlling the wrong display. If so, manually set the oled_screen value to the correct value (check the configuration section).

Contribute

If you found bugs, report them on the issues page. If you modified something, make a pull request.

Community

There is a channel for this project on this server. If more will be required, more will be provided. Discord: https://discord.gg/t4nV3gpJbU

lawleagle/oled-linux