Use variables for automation triggers & conditions

[le_top]

I want to improve the efficiency of a script that manages a fan, and avoid repeating hard coded values.

So I tried to add variables:

alias: Ventilation SDB New
mode: restart
variables:
  max_dew: 14
  min_dew: '{{ max_dew - 0.2 }}'
  max_ext_dew: '10'
  ext_dew_limit: '{{ max_ext_dew - 0.2 }}'
description: Ventilation SDB
trigger:
  - platform: numeric_state
    entity_id: sensor.sdb_dewpoint
    above: '{{ max_dew }}'
    for:
      hours: 0
      minutes: 0
      seconds: 0
  - platform: numeric_state
    entity_id: sensor.sdb_dewpoint
    below: '13.8'
    for:
      hours: 0
      minutes: 0
      seconds: 0
  - platform: numeric_state
    entity_id: sensor.exterieur_dewpoint
    below: '10'
  - platform: numeric_state
    entity_id: sensor.exterieur_dewpoint
    above: '20'
  - platform: event
    event_type: homeassistant_start
action: null

In the first ‘above’ parameter in the sample code, I have written above: '{{ max_dew }}', but the UI complains with “Message malformed: expected float for dictionary value @ data[‘above’]” . I also tried above: "{% max_dew | float %}" and other variations without success.

My intent is to reuse these variables in action conditions as well.

Is this possible? If yes, what is the right way to do it?

[petro]

Variables are only resolved after the trigger occurs. Secondly, you can only use templates in fields that allow templates.

[le_top]

@petro Thank you for your answer.

[petro]

I suggest you explain your endgoal. You can likely achieve what you want to acheive with a single automation using templates in other areas.

[le_top]

I manage the extraction fan in the bathroom using an automation that enables the fan if the absolute humidity is above a given level and the exterior humidity is below a certain level.

I already have the automation further below which works, but has the following side-effects:

• While the fan is on, it’s filling up the log with the checks in the repeat…while loop;
• When changing a limit, I have to change it in multiple locations.

So I wanted to:

• Use variables for the limits so that they are easier to adjust;
• Not use a repeat…until, but rather trigger on the hystereris levels and when the fan is on/off, check if it has to be turned off/on according to the hysteresis levels.
• Continue to use a single automation.

alias: Ventilation SDB
description: Ventilation SDB
trigger:
  - platform: numeric_state
    entity_id: sensor.sdb_dewpoint
    above: '14'
    for:
      hours: 0
      minutes: 0
      seconds: 0
  - platform: numeric_state
    entity_id: sensor.exterieur_dewpoint
    below: '11.5'
  - platform: event
    event_type: homeassistant_start
condition:
  - condition: or
    conditions:
      - condition: and
        conditions:
          - condition: numeric_state
            entity_id: sensor.exterieur_dewpoint
            below: '11.5'
          - condition: numeric_state
            entity_id: sensor.sdb_dewpoint
            above: '14'
      - condition: state
        entity_id: light.sonoff_01minizb_4febc024_on_off
        state: 'on'
action:
  - type: turn_on
    device_id: 3c3d6f675c5d59e015c83cfd7d4282ed
    entity_id: light.sonoff_01minizb_4febc024_on_off
    domain: light
  - repeat:
      sequence:
        - delay:
            hours: 0
            minutes: 2
            seconds: 0
            milliseconds: 0
      while:
        - condition: and
          conditions:
            - condition: numeric_state
              entity_id: sensor.sdb_dewpoint
              above: '13.8'
            - condition: numeric_state
              entity_id: sensor.exterieur_dewpoint
              below: '10.5'
  - type: turn_off
    device_id: 3c3d6f675c5d59e015c83cfd7d4282ed
    entity_id: light.sonoff_01minizb_4febc024_on_off
    domain: light
mode: restart

The following trace shows an execution of this automation where I had the loop delay set to 15 seconds (which I now increased to 2 minutes):

[petro]

You can make 2 input_numbers and use them in all those places. Secondly, is there any reason why you aren’t using a wait_for_trigger instead of the while loop? Use wait for trigger with 2 triggers and a timeout of 40 minutes where you continue on timeout.

example template trigger based on an input number

{{ states('sensor.exterieur_dewpoint') | float < states('input_number.exterieur_dewpoint_threshold') | float - 1.0 }}

[le_top]

1. Ok, I’ll try with input numbers - I thought that this would prompt the user to input numbers in the UI.
2. I do not remember if I considered wait for trigger. I guess the main reason is that I am not intimate with this part of HA.

[petro]

You can hide them from the UI.

[le_top]

I probably tried the ‘wait_for_trigger’ - the issue I had with it is that it only triggers when one of the values change, so not when the condition is already true when wait_for_trigger is evaluated.

I’ll probably get away with it when used in a regular way, but when starting it manually, the fan is turned on (the condition is skipped) and not turning off while the humidity levels are low enough already.
I think I went with the solution that I could test.

For now, I am not using input numbers yet (as far as I understand they haved to be defined “outside” the automation), but I have:

alias: Ventilation SDB
description: Ventilation SDB
trigger:
  - platform: numeric_state
    entity_id: sensor.sdb_dewpoint
    above: '14'
  - platform: numeric_state
    entity_id: sensor.exterieur_dewpoint
    below: '11.5'
  - platform: event
    event_type: homeassistant_start
    id: ha_restart
condition:
  - condition: or
    conditions:
      - condition: and
        conditions:
          - condition: numeric_state
            entity_id: sensor.exterieur_dewpoint
            below: '11.5'
          - condition: numeric_state
            entity_id: sensor.sdb_dewpoint
            above: '14'
      - condition: and
        conditions:
          - condition: state
            entity_id: light.sonoff_01minizb_4febc024_on_off
            state: 'on'
          - condition: trigger
            id: ha_restart
action:
  - type: turn_on
    device_id: 3c3d6f675c5d59e015c83cfd7d4282ed
    entity_id: light.sonoff_01minizb_4febc024_on_off
    domain: light
  - wait_for_trigger:
      - platform: template
        value_template: >-
          {{ states('sensor.sdb_dewpoint') | float < 13.8 or
          states('sensor.exterieur_dewpoint') | float > 12 }}
  - type: turn_off
    device_id: 3c3d6f675c5d59e015c83cfd7d4282ed
    entity_id: light.sonoff_01minizb_4febc024_on_off
    domain: light
mode: restart

[le_top]

While the wait_for_trigger did not have a timeout specified and I did not intervene on the automation (no update, no cancel), the trace shows the 'wait_for_trigger` was canceled, so the fan continued running beyond 12:45PM at which time the trigger condition was met:

.

I am going to test this one more time without changing the automation.

[petro]

your automation is set to restart. Change your automation to single.

[le_top]

Ok, I’ll change it to single which will not hurt due to the changes.

However the automation documentation about modes does not hint there is a difference between restart and single regarding the observed cancelation.

[petro]

The first line in the docs you linked state what it does.

Start a new run after first stopping previous run.

vs single

Do not start a new run. Issue a warning.

Even the image shows you what it does

[Markus99 (Mark)]

Here’s a previous post of mine how I run a bathroom fan based on humidity.

[Automation] Shower detection: trigger when humidity increases in 10 minutes?

To throw another way to accomplish this out there. I use the Average Sensor (available via HACS [also here: GitHub - Limych/ha-average: Average Sensor for Home Assistant]). - platform: average name: Master Bathroom Humidity Average duration: days: 1 entities: - sensor.master_bathroom_sensor_relative_humidity_measurement I then created an input_number which saves a threshold. This is used so I can easily update this threshold without having to restart HA. master_bath_humidity_t…

Uses average humidity inside and a binary sensor + automation.