How do you reference sensor entity_id or name or friendly_name in automation triggered by a value_template?

Configuration
1

I have an automation that checks whether several sensors have been updated recently. If one of the sensors has not been updated, I want the message to identify the specific sensor that triggered the automation.

The automation is of form:

  alias: No Recent Sensor Update
  trigger:
    - platform: template
      value_template:
        "{{ ((as_timestamp(now()) - as_timestamp(states.sensor.ambientweather_f007th_1_15_temperature.last_updated))
        / 60) > 30  }}"
   ...
   ...
    - platform: template
      value_template:
        "{{ (as_timestamp(now()) - as_timestamp(states.sensor.ambientweather_f007th_2_17_temperature.last_updated))
        > 30 }}"
  condition: []
  action:
    - service: notify.notify
      metadata: {}
      data:
        title: Sensor Offline/Unavailable for >30 minutes
        message: "{{ trigger.entity_id }}"
  mode: single

This gives an error of form:

AttributeError: 'NoneType' object has no attribute 'lower'

which I believe is due to the fact that trigger.entity_id doesn’t exist.

So how do I tell which of the sensors triggered the automation when the sensor is embedded in a value_template?

(I know there are kludgey ways where I could recheck the conditions in the ‘action’ statement to see which one matches but I would like to avoid that)

2

You can’t without re-evaluating. Much easier way:

  trigger:
    - platform: state
      entity_id:
        - sensor.ambientweather_f007th_1_15_temperature
        - sensor.ambientweather_f007th_2_17_temperature
      for: "00:30:00"

Then you can use trigger.entity_id.

Slight nuance: this will trigger if the state hasn’t changed for 30 minutes. Your template version also watches the sensor attributes because you’re using last_updated rather than last_changed (ref).

An alternative would be to use trigger IDs:

  trigger:
    - platform: template
      id: sensor.ambientweather_f007th_1_15_temperature
      value_template:
        "{{ ((as_timestamp(now()) - as_timestamp(states['sensor.ambientweather_f007th_1_15_temperature']['last_updated'])) / 60) > 30 }}"
   ...
   ...
    - platform: template
      id: sensor.ambientweather_f007th_2_17_temperature
      value_template:
        "{{ (as_timestamp(now()) - as_timestamp(states['sensor.ambientweather_f007th_2_17_temperature']['last_updated'])) > 30 }}"

Then trigger.id is the entity ID.

Your second trigger is only waiting 30s not 30m, by the way.

3

Thanks.
To save a little typing, is it possible to reference the name of the sensor using the trigger.id variable within the value_template. Or said another way this would allow me to type the name of the sensor only once. Something like:

trigger:
    - platform: template
      id: sensor.ambientweather_f007th_1_15_temperature
      value_template:
        "{{ ((as_timestamp(now()) - as_timestamp(states('trigger.id').last_updated)) / 60) > 30 }}"
   ...
   ...
    - platform: template
      id: sensor.ambientweather_f007th_2_17_temperature
      value_template:
        "{{ (as_timestamp(now()) - "{{ ((as_timestamp(now()) - as_timestamp(states('trigger.id').last_updated)) / 60) > 60 }}"

I am asking because it doesn’t work for me so perhaps I just have the syntax wrong.