ddcci-plasmoid-backend on Pypi

This widget allows you to adjust the brightness of external monitors. We accomplish that using DDC/CI, a protocol that allows your computer to control monitors and change options like the brightness or contrast.
A seamless integration into the Plasma desktop is a major goal of this project. The widget is versatile and can be used as a standalone widget or integrated into the system tray.
Notebook monitors are currently unsupported because they use different interfaces to communicate with the operating system.

Requirements

Python 3.8 or newer
python library fasteners
ddcutil 1.4.1 or newer (older versions may work but caused issues in the past)

ddcutil is a command line utility to control external monitors. We use ddcutil to detect supported monitors and adjust their brightness. For additional details, refer to the great ddcutil documentation. Note that additional steps may be required if you are using a NVIDIA GPU, see Special Nvidia Driver Settings in the ddcutil documentation.

Install the ddcutil from your distribution's repositories. (Arch Linux)

By default, ddcutil can only be used the root user. Little configuration is required to allow non-root users to use it:

$ sudo usermod -aG i2c <username>

If the group i2c doesn't exit, create it first:

$ sudo groupadd --system i2c

Finally, you need to install an udev rule to allow members of the group i2c to access i²c devices:

$ sudo cp /usr/share/ddcutil/data/45-ddcutil-i2c.rules /etc/udev/rules.d

Now, you can verify that ddcutil is working correctly:

$ ddcutil detect

The output should look something like that:

Display 1
   I2C bus:  /dev/i2c-9
   DRM connector:           card0-DP-1
   EDID synopsis:
      Mfg id:               DEL - Dell Inc.
      Model:                DELL S2721DGF
      Product code:         16857  (0x41d9)
      Serial number:        XXXXXXXX
      Binary serial number: XXXXXXXX (0xXXXXXXXX)
      Manufacture year:     2022,  Week: 35
   VCP version:         2.1

Display 2
   I2C bus:  /dev/i2c-10
   DRM connector:           card0-DP-2
   EDID synopsis:
      Mfg id:               DEL - Dell Inc.
      Model:                DELL U2417H
      Product code:         16615  (0x40e7)
      Serial number:        XXXXXXXX
      Binary serial number: XXXXXXXX (0xXXXXXXXX)
      Manufacture year:     2018,  Week: 22
   VCP version:         2.1

If the output is the following:

No /dev/i2c devices exist.
ddcutil requires module i2c-dev.

the module is not compiled into the kernel, and you need to load the i2c_dev kernel module. Load it automatically during every boot:

$ echo i2c_dev | sudo tee /etc/modules-load.d/i2c_dev.conf

or load it once:

$ sudo modprobe i2c_dev

2. Install the backend

Install the backend from PyPI using the following command:

$ pip install --user ddcci-plasmoid-backend

You can also use pipx to install the backend. This is the recommended option if your distribution doesn't allow pip for global packages, see PEP-668.

$ pipx install ddcci-plasmoid-backend

About pipx:

Overview: What is pipx?

pipx is a tool to help you install and run end-user applications written in Python. It's roughly similar to macOS's brew, JavaScript's npx, and Linux's apt.

It's closely related to pip. In fact, it uses pip, but is focused on installing and managing Python packages that can be run from the command line directly as applications.

How is it Different from pip?

pip is a general-purpose package installer for both libraries and apps with no environment isolation. pipx is made specifically for application installation, as it adds isolation yet still makes the apps available in your shell: pipx creates an isolated environment for each application and its associated packages.

Install the official package from the KDE store or install it directly from the repository:

$ git clone https://github.com/davidhi7/ddcci-plasmoid.git
$ cd ddcci-plasmoid
$ kpackagetool5 --install plasmoid
# or upgrade the plasmoid:
$ kpackagetool5 --upgrade plasmoid

Note: If you used pipx to install the backend in the previous step, the widget setting Backend executable command should be ~/.local/bin/ddcci_plasmoid_backend (which is the default installation path of pipx).

This widget can be displayed within the system tray or as a standalone widget.

The output of `ddcutil detect` starts with `Unable to open directory /sys/bus/i2c/devices/i2c--1: No such file or directory`

This is a bug in older ddcutil versions which it is fixed in ddcutil v1.4.1. In some cases, it may cause the backend to fail.

History

v0.1.9 2023-11-02

Fix bug that prevents monitors from being properly detected when using ddcutil 2.0.0 (#49)

v0.1.8 2023-08-26

Ignore monitors if VCP version detection failed by ddcutil (#39)

v0.1.7 2023-08-22

Fix backend command not updating after changing it in the configuration field (#17, thanks CatEricka)

v0.1.6 2023-07-09

Fix backend errors with certain NVIDIA GPUs
Fix compatibility with Python 3.9 and 3.8

v0.1.5 2023-04-16

Allow integration into the system tray (#2)
Scrolling while hovering sliders now works (#15, thanks CatEricka)
Add translations for Simplified Chinese (thanks CatEricka) and German (by myself)
Lower minimum Python version to 3.8
Add option to specify the backend executable command manually (thanks CatEricka)

v0.1.4 2023-04-12

Fix error if serial number is missing (#6)

v0.1.3 2023-04-11

Add padding to widget title
Fix duplicate monitor detection (#1)
Expand debug output

v0.1.2 2023-04-09

Fix KDE widget configuration not loading

v0.1.1 2023-04-09

First public release

ddcci-plasmoid-backend
Release 0.1.9

Release 0.1.9

0.1.0

0.1.1

0.1.4

0.1.5

0.1.6

0.1.3

0.1.10

0.1.9

0.1.8

Documentation

KDE Plasma Widget for external monitor brightness adjustment

Requirements

Setup

1. Install and configure ddcutil

2. Install the backend

Overview: What is pipx?

How is it Different from pip?

3. Install the widget itself

4. Display the widget

Integrate into systemtray:

standalone widget

Common issues

Installing the backend with `pip` fails, printing `This environment is externally managed`