Why donât you create a group with those two lights (or sets of lights) and then change the brightness to the group instead of individual lights?
If you still wanna do with an automation, try this:
description: ""
mode: single
trigger:
- platform: state
entity_id:
- light.dining_room_lights
attribute: brightness
condition:
- condition: state
entity_id: light.upstairs_hallway_lights
state: "on"
action:
- service: light.turn_on
data:
brightness_pct: "{{ state_attr('light.dining_room_lights', 'brightness_pct') | int(50) }}"
target:
entity_id: light.upstairs_hallway_lights
So I have implemented the above.
When I change the brightness on the dining room lights via the peco, the hallway lights will react (1 Time) but will not copy the brightness. They go to 50 % range regardless. When I turn the hallway lights off and on again, then they once again will only react once when I change the dining room brightness.
If you want to mirror off also then you can do like this:
description: ""
mode: single
trigger:
- platform: state
entity_id:
- light.dining_room_lights
attribute: birghtness
id: "on"
- platform: state
entity_id:
- light.dining_room_lights
to: "off"
id: "off"
condition: []
action:
- choose:
- conditions:
- condition: trigger
id: "on"
sequence:
- service: light.turn_on
data:
brightness: "{{ state_attr('light.dining_room_lights', 'brightness') | int }}"
target:
entity_id: light.upstairs_hallway_lights
- conditions:
- condition: trigger
id: "off"
sequence:
- service: light.turn_off
target:
entity_id: light.upstairs_hallway_lights
data: {}
Sorry about the first edit. My phone wouldnât copy the complete yaml. It keep insisting on a partial or old copyâŚ
2 Likes
Hey, so this is not copying the brightness. When I dim the dining room lights, the hallway lights donât change, this is only for the off switch.
Can you show us the entities you have here in developer tools?
Thatâs not developer tools
In developer tools Im not seeing an entities tab, Im sorryâŚ
Sorry I confused you.
I meant I want to see the entities as in the light.dining⌠in the developer tools â states.
The developer tools â states show all the attributes of an entity and the real values.
So keep both lights on and take a screenshot of what the states and attributes are on that view
And could you please share you latest version of your automation (yaml)?
This is the latest,
description: ""
trigger:
- platform: state
entity_id:
- light.dining_room_lights
attribute: birghtness
id: "on"
- platform: state
entity_id:
- light.dining_room_lights
to: "off"
id: "off"
condition: []
action:
- choose:
- conditions:
- condition: trigger
id: "on"
sequence:
- service: light.turn_on
data:
brightness: "{{ state_attr('light.dining_room_lights', 'brightness') | int }}"
target:
entity_id: light.upstairs_hallway_lights
- conditions:
- condition: trigger
id: "off"
sequence:
- service: light.turn_off
target:
entity_id: light.upstairs_hallway_lights
data: {}
mode: single
Looks like there is a typo here.
Try this:
description: ""
trigger:
- platform: state
entity_id:
- light.dining_room_lights
attribute: brightness
id: "on"
- platform: state
entity_id:
- light.dining_room_lights
to: "off"
id: "off"
condition: []
action:
- choose:
- conditions:
- condition: trigger
id: "on"
sequence:
- service: light.turn_on
data:
brightness: "{{ state_attr('light.dining_room_lights', 'brightness') | int }}"
target:
entity_id: light.upstairs_hallway_lights
- conditions:
- condition: trigger
id: "off"
sequence:
- service: light.turn_off
target:
entity_id: light.upstairs_hallway_lights
data: {}
mode: restart
1 Like
Oops 
my bad
2 Likes
Amazing Guys, How do I mark this as Solved?
and how would one make this backwards compatible so the Dining room also listens to the hallway?
Ultimately, what Iâm looking to do, and Ill make a separate post for it, is have all my pot lights upstairs brightness synced, and all listening to each other, but if I Quickly press the light on 3 times, it adds it to the sync group, and when I turn it off 3 times or something, if removes it⌠So I can add and remove from the lutron wall switch⌠
Itâs probably doable but I donât know how these switches work.
I believe you would need one boolean per light to be âin or out of groupâ.
Then (I would do this way), use a history stats counter to count how many times the light has been switched in a short period.
Use this as a trigger to toggle the boolean.
Regarding syncing all lights, I believe we would have to loop through all lights you have, if boolean is on for this specific light, then set brightness.
This is not a simple automation, we would need to see a few of the entities (just list them) then perhaps we could help you out with this.
Itâs always better to get real entity names both for you and us.
Next time, come with all your known requirements from the beginning, as that might drive to a different approach. 
But letâs go⌠Try this:
description: ""
trigger:
- id: "brightness"
platform: state
entity_id:
- light.dining_room_lights
- light.upstairs_hallway_lights
attribute: brightness
- id: "off"
platform: state
entity_id:
- light.dining_room_lights
- light.upstairs_hallway_lights
to: "off"
condition: []
action:
- choose:
- conditions:
- condition: trigger
id: "brightness"
sequence:
- service: light.turn_on
data:
brightness: "{{ state_attr(trigger.entity_id, 'brightness') | int }}"
target:
entity_id:
- light.dining_room_lights
- light.upstairs_hallway_lights
- conditions:
- condition: trigger
id: "off"
sequence:
- service: light.turn_off
entity_id:
- light.dining_room_lights
- light.upstairs_hallway_lights
data: {}
mode: restart
But again, creating a light group makes more sense in this case. You will have a new light entity that represents both lights, than any change to that new entity will apply to all the lights. No need for creating an automation for this.
In order to create a light group, go to Settings > Devices and Services, select the tab Helpers and then click on Create helper (bottom right), then select Group > Light group
Then give a name for your new light and select all the lights that should be part of that group:
And click Submit.
Now you can add this new light to your dashboards or automation, and everything you ask that light to do (turn on/off, change brightness, color, etc) will happen on both lights at the same time. And you can still control your lights individually using the original entities.
1 Like
I have shared my opinion about this on this other post:
This is the Problem with Home assistant. You keep thinking about more stuff :).
I have actually scraped this entire idea and now have everything on Adaptive brightness from GitHub - basnijholt/adaptive-lighting: Adaptive Lighting custom component for Home Assistant.
But I am learning with every solution going through some tutorials for YAML Now
Its unreal. This way I donât need to touch anything anyway. And its working perfectly.
1 Like