# Brightness control of external monitors with ddcci-backlight
**URL:** https://discourse.nixos.org/t/brightness-control-of-external-monitors-with-ddcci-backlight/8639
**Category:** Development
**Created:** [August 19, 2020, 6:24am UTC](https://discourse.nixos.org/t/brightness-control-of-external-monitors-with-ddcci-backlight/8639 "2020-08-19T06:24:42Z")
**Posts on this page:** 3
**Page:** 2
### Author:  [@doronbehar](https://discourse.nixos.org/u/doronbehar)
#### Post date: [October 30, 2025, 4:14pm UTC](https://discourse.nixos.org/t/brightness-control-of-external-monitors-with-ddcci-backlight/8639/21 "2025-10-30T16:14:58Z")
Thanks everyone for sharing your solutions. I’d love to get some feedback upon:
>
>
> Other commits in this PR (purely semantics)
>
> \- \*\*ddccontrol: no with lib; in met…a\*\*
> \- \*\*ddccontrol: use tag in src\*\*
> \- \*\*ddccontrol: use finalAttrs pattern\*\*
> \- \*\*ddccontrol: add doronbehar as co-maintainer\*\*
> \- \*\*ddccontrol-db: no with lib; in meta\*\*
> \- \*\*ddccontrol-db: add doronbehar as co-maintainer\*\*
> \- \*\*ddccontrol-db: use finalAttrs pattern\*\*
> \- \*\*ddccontrol-db: use tag in src\*\*
>
> See also:
>
> https://discourse.nixos.org/t/brightness-control-of-external-monitors-with-ddcci-backlight/8639/
>
> \## Things done
>
> \- Built on platform:
> - \[x\] x86\_64-linux
> - \[\] aarch64-linux
> - \[\] x86\_64-darwin
> - \[\] aarch64-darwin
> \- Tested, as applicable:
> - \[\] \[NixOS tests\] in \[nixos/tests\].
> - \[\] \[Package tests\] at \`passthru.tests\`.
> - \[\] Tests in \[lib/tests\] or \[pkgs/test\] for functions and "core" functionality.
> \- \[\] Ran \`nixpkgs-review\` on this PR. See \[nixpkgs-review usage\].
> \- \[\] Tested basic functionality of all binary files, usually in \`./result/bin/\`.
> \- Nixpkgs Release Notes
> - \[\] Package update: when the change is major or breaking.
> \- NixOS Release Notes
> - \[\] Module addition: when adding a new NixOS module.
> - \[x\] Module update: when the change is significant.
> \- \[x\] Fits \[CONTRIBUTING.md\], \[pkgs/README.md\], \[maintainers/README.md\] and other READMEs.
>
> \[NixOS tests\]: https://nixos.org/manual/nixos/unstable/index.html#sec-nixos-tests
> \[Package tests\]: https://github.com/NixOS/nixpkgs/blob/master/pkgs/README.md#package-tests
> \[nixpkgs-review usage\]: https://github.com/Mic92/nixpkgs-review#usage
>
> \[CONTRIBUTING.md\]: https://github.com/NixOS/nixpkgs/blob/master/CONTRIBUTING.md
> \[lib/tests\]: https://github.com/NixOS/nixpkgs/blob/master/lib/tests
> \[maintainers/README.md\]: https://github.com/NixOS/nixpkgs/blob/master/maintainers/README.md
> \[nixos/tests\]: https://github.com/NixOS/nixpkgs/blob/master/nixos/tests
> \[pkgs/README.md\]: https://github.com/NixOS/nixpkgs/blob/master/pkgs/README.md
> \[pkgs/test\]: https://github.com/NixOS/nixpkgs/blob/master/pkgs/test
>
> \---
>
> Add a :+1: \[reaction\] to \[pull requests you find important\].
>
> \[reaction\]: https://github.blog/2016-03-10-add-reactions-to-pull-requests-issues-and-comments/
> \[pull requests you find important\]: https://github.com/NixOS/nixpkgs/pulls?q=is%3Aopen+sort%3Areactions-%2B1-desc
Which will hopefully improve the situation for some of us.
---
### Author:  [@cmm](https://discourse.nixos.org/u/cmm)
#### Post date: [November 29, 2025, 8:45pm UTC](https://discourse.nixos.org/t/brightness-control-of-external-monitors-with-ddcci-backlight/8639/22 "2025-11-29T20:45:04Z")
it does improve things, but note that you need
```auto
boot.extraModulePackages = [config.boot.kernelPackages.ddcci-driver];
```
for `ddcci_backlight` module to exist 🙂
---
### Author:  [@doronbehar](https://discourse.nixos.org/u/doronbehar)
#### Post date: [November 30, 2025, 9:18am UTC](https://discourse.nixos.org/t/brightness-control-of-external-monitors-with-ddcci-backlight/8639/23 "2025-11-30T09:18:31Z")
Thanks @cmm 🙂 I guess something else in my config already enabled this module. Your review is welcome upon:
>
>
> \## Things done
>
> A followup to:
>
> \- https://discourse.nixos.org/t/brightness-c…ontrol-of-external-monitors-with-ddcci-backlight/8639/22
> \- https://github.com/NixOS/nixpkgs/pull/457031
>
> CC @cmm
>
> \- Built on platform:
> - \[\] x86\_64-linux
> - \[\] aarch64-linux
> - \[\] x86\_64-darwin
> - \[\] aarch64-darwin
> \- Tested, as applicable:
> - \[\] \[NixOS tests\] in \[nixos/tests\].
> - \[\] \[Package tests\] at \`passthru.tests\`.
> - \[\] Tests in \[lib/tests\] or \[pkgs/test\] for functions and "core" functionality.
> \- \[\] Ran \`nixpkgs-review\` on this PR. See \[nixpkgs-review usage\].
> \- \[\] Tested basic functionality of all binary files, usually in \`./result/bin/\`.
> \- Nixpkgs Release Notes
> - \[\] Package update: when the change is major or breaking.
> \- NixOS Release Notes
> - \[\] Module addition: when adding a new NixOS module.
> - \[\] Module update: when the change is significant.
> \- \[x\] Fits \[CONTRIBUTING.md\], \[pkgs/README.md\], \[maintainers/README.md\] and other READMEs.
>
> \[NixOS tests\]: https://nixos.org/manual/nixos/unstable/index.html#sec-nixos-tests
> \[Package tests\]: https://github.com/NixOS/nixpkgs/blob/master/pkgs/README.md#package-tests
> \[nixpkgs-review usage\]: https://github.com/Mic92/nixpkgs-review#usage
>
> \[CONTRIBUTING.md\]: https://github.com/NixOS/nixpkgs/blob/master/CONTRIBUTING.md
> \[lib/tests\]: https://github.com/NixOS/nixpkgs/blob/master/lib/tests
> \[maintainers/README.md\]: https://github.com/NixOS/nixpkgs/blob/master/maintainers/README.md
> \[nixos/tests\]: https://github.com/NixOS/nixpkgs/blob/master/nixos/tests
> \[pkgs/README.md\]: https://github.com/NixOS/nixpkgs/blob/master/pkgs/README.md
> \[pkgs/test\]: https://github.com/NixOS/nixpkgs/blob/master/pkgs/test
>
> \---
>
> Add a :+1: \[reaction\] to \[pull requests you find important\].
>
> \[reaction\]: https://github.blog/2016-03-10-add-reactions-to-pull-requests-issues-and-comments/
> \[pull requests you find important\]: https://github.com/NixOS/nixpkgs/pulls?q=is%3Aopen+sort%3Areactions-%2B1-desc
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