Can I trigger an automation by scene being activated?

Configuration
1

Here’s what I am trying to do and how I’m trying to do it.
Alternate suggestions about how to achieve this same result are totally welcome.

I have an RGB strip next to my bed. (WS2812B controlled by WLED)
I have used this python code to create the ability to fade it up or down: Light Fader by Transition Time
I have set up an automation at 6:30am on weekdays to turn it on, blue, 1% and then fade up to 60% over 30 minutes. This works beautifully.
The other side is I want to make it fade out over 30 minutes at night when I go to bed which is a variable time so I can’t schedule it.
I use both homekit and alexa integrations so I can use voice commands with either siri or alexa.
I have written a script that sets the lights red, 45% brightness, and then fades the lights down to 0 (turns off) over 30 minutes. This works.
I would like to be able to trigger this script by Alexa, but Alexa can not have scripts or automations as entities, only scenes.

So what I need is a way to be able to activate a scene that then triggers my script and this is what I am stuck on.

How could I make this work?

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2

I can confirm that you cannot use a scene to turn on a script.

However, turning on a scene produces an event. We can use that event to trigger an automation to call your script.

- alias: 'On My_Scene Activated'
  trigger:
    platform: event
    event_type: 'call_service'
    event_data:
      domain: scene
      service: turn_on
      service_data:
        entity_id: 'scene.my_scene'
  action:
    service: script.turn_on
    entity_id: script.my_script

So when my_scene is turned on, the associated event is detected by the automation and turns on my_script.

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3

Another approach might be a template switch. I don’t use either Homekit or Alexa integrations, but it looks like the Alexa integration allows you to work with a switch entity, so you could probably use the turn_on: series of actions in the template switch to run your script. So the voice command would be “turn on your_switch_name”.

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4

I tried using an automation triggered by the scene being activated like this:

- id: '1598543301938'
  alias: Sleepy Light Automation
  description: ''
  trigger:
  - entity_id: scene.bed_light_on_red_45
    platform: state
    to: 'on'
  condition: []
  action:
  - data: {}
    entity_id: script.sleepy_light
    service: script.sleepy_light
  mode: single

But activating the scene does not trigger the automation.
Have I missed something here?

5

Yes. A scene’s state never changes to on.

If you look at it’s state in Developer Tools > States you’ll see it is scening (whatever that means). It doesn’t change when the scene is activated (i.e. “turned on”).

That’s why I suggested you use an Event Trigger (not a State Trigger).

6

Huh??? All my scenes turn on scripts…

EDIT… and none of them work lol!!! Never noticed because I never call them anyway (Google Assistant uses the script direct)

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7

I got it working like this:

If I activate the scene the “event” of that scene activating triggers the automation which calls the script.
It’s a few steps but it works nicely and I am very happy with the result.
Thank you everyone for the assist, seriously, thank you!

Here is the code for the automation that worked for me:

- id: '1598543301938'
  alias: Sleepy Light Automation
  trigger:
  - event_data:
      domain: scene
      service: turn_on
      service_data:
        entity_id: scene.bed_light_on_red_45
    event_type: call_service
    platform: event
  action:
  - entity_id: script.sleepy_light
    service: script.turn_on
  mode: single

@mrsnyds - I didn’t go down the path of a template switch to solve this one but I can see how it would work. You have introduced me to another great feature of this platform I wasn’t aware of, thank you for that. I will be using these in the future.

2 Likes
8

The example I posted works (and is the one you ultimately used) yet you marked the post with the example that doesn’t work with the Solution tag. Any particular reason for that?

9

An error on my part.
I have changed it to mark your post as the solution.
Thank you for your vigilance.

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10

I tried the suggested solution and it did work but for all kind of events e.g. on home assistant restart

11

Hi, i tried the code that u wrote. If im pressing the aktivate button on a scene in the scenes tab, my automation gets triggered. If i aktivate the scene with another automation for example than nothing happens.
Does someone has an idea?

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