Home Assistant EWMA template sensor

configuration.yml

  - trigger:
      - id: state_changed
        platform: state
        entity_id: sensor.147334558305449_indoor_temperature
        to: null
      - id: time_pattern
        platform: time_pattern
        seconds: "/30"
    action:
      - variables:
          tau: 300
          precision: 1
          sensor_name: 147334558305449_indoor_temperature
          entity_id: sensor.147334558305449_indoor_temperature
    sensor:
      - name: "Heat Pump Smoothed Indoor Temperature"
        unique_id: b414f387d861985d8849c56a1b263317
        icon: mdi:home-thermometer
        availability: "{{ states(entity_id) | is_number }}"
        device_class: temperature
        state: >-
          {% set last_state = this.state | float(states(entity_id) | float) %}
          {% set last_state_changed = this.last_changed
            | as_timestamp(states.sensor[sensor_name].last_changed | as_timestamp) %}
          {% set next_state = trigger.from_state.state
              | float(states(entity_id) | float)
            if trigger.id == 'state_changed'
            else states(entity_id) | float %}
          {% set next_state_changed = now() | as_timestamp %}
          {% set dt = next_state_changed - last_state_changed %}
          {% set w = e ** (-dt / tau) %}
          {% set state = last_state * w + next_state * (1-w) %}
          {% if trigger.id == 'state_changed' or state | round(precision) != last_state | round(precision) %}{{ state }}{% else %}{{ last_state }}{% endif %}
        unit_of_measurement: "°C"
        state_class: measurement