change backlight brightness in linux with python

linux screen brightness
xbacklight ubuntu

I'm working on a python project which should be able to control my backlight brightness. I working with Ubuntu 17.04 and I already locate where the file is that show my backlight brightness

/sys/class/backlight/acpi_video0/brightness

the command that I can use in the bash terminal to change the value is

sudo su -c 'echo 12 > /sys/class/backlight/acpi_video0/brightness'

but I have no clue how to implement this in a py project. Maybe this is also the wrong way to start.

Thank you Guys for probably helping me out.

In Ubuntu, I achieved this using xbacklight package and python's os.system() imported from os module.

Installation :

sudo apt install xbacklight

Python command:

os.system('xbacklight -set ' + str(value)) where value is the input.

How to use cron + python to regularly adjust screen brightness , In older kernels there was brightness control file somewhere in /proc , but I think that it was the same functionality as /sys in your code snippet. In this /proc file  Automatically adjust Linux display brightness. The auto-adjust-display-brightness program automatically adjusts the brightness of Linux computer displays based on whether it's light or dark outside. To get it working you create a configuration file defining your physical location (this is how it figures out whether it's light or dark outside

you can use either os.system() or subprocess.Popen()

Not really recommended, but I see no harm in it for a personal project where the input isn't coming from an external source.. That being said, one should take care using this, because you will be executing straight from your command line, so anything your CLI can do, this can do. You have been warned.

Using os.system() (you might have to prepend the path to your shell to the command. This is usually /bin/bash in Linux.):

import os os.system('echo "your command goes here"')

if that doesn't work, then it should look something like:

os.system('/bin/bash echo "your command goes here"')

Using subprocess.Popen() (again, you might need to prepend the path to your shell before the rest of the command.:

import subprocess subprocess.Popen('echo "your command goes here"')

Once again, I will say, this is NOT recomended for frequent usage especially where outside sources may affect the output of the command being ran. Only use this when you KNOW what will be input into the command.

brightness-control · GitHub Topics · GitHub, MacOS app to change the screen brightness on the menubar. electron macos menubar osx A linux kernel module to control brightness using keyboard. This is an Introduction to image processing with Python and OpenCV. python opencv  To change the brightness of your screen, click the system menu on the right side of the top bar and adjust the screen brightness slider to the value you want to use. The change should take effect immediately. Many laptop keyboards have special keys to adjust the brightness. These often have a picture that looks like the sun.

So I do a bit of research and on a this site https://wiki.archlinux.org/index.php/backlight I have found the command

gdbus call --session --dest org.gnome.SettingsDaemon.Power --object-path /org/gnome/SettingsDaemon/Power --method org.freedesktop.DBus.Properties.Set org.gnome.SettingsDaemon.Power.Screen Brightness "<int32 50>"

I have no idea how this works but i changed my backlight.

It only works on gnome!! but because i use gnome and the application should be for gnome it is OK for me

my function now looks like this:

def change_brightness(self, value):
    os.system('gdbus call --session --dest org.gnome.SettingsDaemon.Power --object-path /org/gnome/SettingsDaemon/Power --method org.freedesktop.DBus.Properties.Set org.gnome.SettingsDaemon.Power.Screen Brightness "<int32 ' + str(value) + '>"')

the value must be between 0 and 100

xolox/python-auto-adjust-display-brightness: Automatically , Automatically adjust Linux display brightness - https://pypi.python.org/pypi/auto-​adjust-display-brightness to manually adjust the brightness of my laptop screen and the external monitor attached to my laptop to avoid unnecessary eye strain. So, to adjust contrast and brightness at the same time, do for each pixel: new_value = (old_value - 0.5) × contrast + 0.5 + brightness Bellow a nice function which do the job :

Try this:

def set_brightness(brightness):
    if int(brightness) > 15:
        raise TypeError("Need int 0 < and > 15")
    elif int(brightness) < 0:
        raise TypeError("Need int 0 < and > 15")
    with open("/sys/devices/pci0000:00/0000:00:02.0/backlight/acpi_video0/brightness","w") as bright:
         bright.write(str(brightness))
         bright.close()
set_brightness(0) #Brightness 0-15

auto-adjust-display-brightness · PyPI, Automatically adjust Linux display brightness. to manually adjust the brightness of my laptop screen and the external monitor attached to my laptop The auto-adjust-display-brightness program is written in Python and is available on PyPI  To install the python-pigpio useful to test the PWM backlight in Python type: sudo apt install python-pigpio Run pigpiod. sudo pigpiod - Try this code example in Python. It wil turn off the screen for 1 sec and the turn on. import pigpio import time port=pigpio.pi() port.write(22,1) time.sleep(1) port.write(22,0)

rpi-backlight · PyPI, A Python module for controlling power and brightness of the official have to run Python code, the GUI and CLI as root when changing the power or brightness: Linux/macOS/Windows machine) you can use linusg/rpi-backlight-emulator . You can change the path #defined by the preprocessor macro DEFAULT_CTRL_DIR to suit your own system. It must point to the directory where the files 'brightness' and 'max_brightness' reside. On my laptop, for example, this path is "/sys/class/backlight/intel_backlight/", however yours may be different.

How to change LCD brightness from command line (or via script , you can also increase and decrease the brightness from present value to echo 400 | sudo tee /sys/class/backlight/intel_backlight/brightness. $ rpi-backlight --board-type tinker-board For all available options see docs. GUI. Open a terminal and run rpi-backlight-gui. Adding a shortcut to the LXDE panel. See docs. Tests. Tests use pytest, install with pip3 install pytest. Now, run from the repository root directory: $ python3 -m pytest Contributing

Changing screen brightness in accordance with human perception , Changing screen brightness in accordance with human perception update to version 3.16 in Arch Linux the function keys for changing screen brightness in my The following Python script does exactly that, and a bit more:. The value inside the max_brightness file is the maximum brightness you can assign to the display, and it's not possible to change. The brightness file actually controls the amount of backligh, you can change it like below. root@host:~# echo 200 > /sys/class/backlight/intel_backlight/brightness

Comments
  • Task 1: fix the permission of the files so you are able to change the brightness without sudo.
  • Yes I have just figured out but I have also no idea how to do this. I have found something useful on here raspberrypi.org/forums/viewtopic.php?t=134390&p=894761 Let me search around a bit than i can post my code
  • This is sysfs not a real filesystem. You may not change its permissions. In Python just open the file, write to it and close it.