Brightness control missing with dual monitor

[miloumeeloo]

What type of installation are you running?

Desktop

Which Linux OS are you using?

Manjaro 26.0.2

Which version of LNXLink has the issue?

2026.2.0

Describe the problem

On my dual monitor setup, only one appears in HA. Both are the same model.
I can change brightness on the one that is detected.

Additional context

~ddcutil detect
Display 1
   I2C bus:  /dev/i2c-6
   DRM_connector:           card1-DVI-D-1
   EDID synopsis:
      Mfg id:               ACR - Acer Technologies
      Model:                KA222Q
      Product code:         1832  (0x0728)
      Serial number:        
      Binary serial number: 
      Manufacture year:     2020,  Week: 16
   VCP version:         2.2

Display 2
   I2C bus:  /dev/i2c-7
   DRM_connector:           card1-HDMI-A-1
   EDID synopsis:
      Mfg id:               ACR - Acer Technologies
      Model:                KA222Q
      Product code:         1832  (0x0728)
      Serial number:        
      Binary serial number: 
      Manufacture year:     2020,  Week: 16
   VCP version:         2.2

Configuration

mqtt:
  prefix: lnxlink
  clientId: xxx
  server: xxx
  port: 1883
  auth:
    user: xxx
    pass: xxx
    tls: false
    keyfile: ''
    certfile: ''
    ca_certs: ''
  discovery:
    enabled: true
    prefix: homeassistant
  lwt:
    enabled: true
    qos: 1
  clear_on_off: true
update_interval: 5
update_on_change: false
modules:
- brightness
- logging_level
- media
- notify
- restart
- screen_onoff
- shutdown
- suspend
- update
- watch_changes
exclude:
- audio_select
- battery
- beacondb
- boot_select
- fullscreen
- gpio
- gpu
- idle
- inference_time
- ir_remote
- keep_alive
- keyboard_hotkeys
- mouse
- power_profile
- restful
- screenshot
- send_keys
- speech_recognition
- systemd
- webcam
- wol
- xdg_open
custom_modules: null
settings:
  media:
    order:
    - gst-play-1.0
    - ffplay
    - mpv
    - cvlc
    - vlc
  statistics: https://analyzer.bkbilly.workers.dev
  brightness:
    autodiscovery: true

Logs

Started LNXlink.
INFO:lnxlink:LNXlink 2026.2.0, Python 3.14.2
INFO:lnxlink:Installing 'dbus-mediaplayer>=2025.6.0'...
INFO:lnxlink:Installing 'dbus-notification>=2025.10.1'...
INFO:lnxlink:Loaded addons: brightness, logging_level, media, notify, restart, screen_onoff, shutdown, suspend, update, watch_changes
INFO:lnxlink:MQTT connection: Success
INFO:lnxlink:MQTT Media Player configuration name: lnxlink/PC-Linux_media_player
INFO:lnxlink:Message received brightness/brightness_acr_ka222q: b'44'
INFO:lnxlink:Changing Brightness to 44 for ACR KA222Q

[bkbilly]

I think I found the issue.
This is because I find the unique name with a combination of manufacturer and the name, but since you have the same monitor, it doesn't work.
I'll push an update for this once I fix it.

[miloumeeloo]

I applied your changes to the script. Both are now detected.
Is it possible to retrieve the control that acts on both monitor at the same time ?

[bkbilly]

You can create a helper template for that by going to Settings -> Devices & services -> Helpers -> Create helper -> Template -> Number.

For the State you can write the following which will search for all the number entities that start with number.desktop_linux_brightness_ and get the average value:

{% set brightness_entities = states.number 
  | selectattr('entity_id', 'search', '^number\.desktop_linux_brightness_') 
  | map(attribute='state') | map('float') | list %}

{{ (brightness_entities | sum / brightness_entities | count) | round(2) if brightness_entities | count > 0 else 0 }}

For the action create the following which will change the value of all number entities that contain the number.desktop_linux_brightness_ entity name:

action: number.set_value
metadata: {}
target:
  entity_id: |
    {{ states.number 
      | selectattr('entity_id', 'search', '^number\.desktop_linux_brightness_') 
      | map(attribute='entity_id') | list }}
data:
  value: "{{ value }}"

This is how it will look: