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+---
+blueprint:
+  author: runejuhl
+  homeassistant:
+    min_version: 2024.6.0
+  name: Radiator external temperature sensor control (0.0.1-alpha)
+  description: |-
+    ## Radiator external temperature sensor control
+
+    Version `0.0.1-alpha`.
+
+    Sets the `external_measured_room_sensor` value on Danfoss Ally TRV, enabling
+    the TRV to adjust the valve based on an external sensor.
+  domain: automation
+  source_url: https://git.petardo.dk/runejuhl/hass-blueprints/raw/branch/dev/blueprints/danfoss_ally_trv_external_sensor.yaml
+
+  input:
+    radiator:
+      name: Radiator thermostat
+      selector:
+        entity:
+          filter:
+            - domain: climate
+    climate_sensor:
+      name: Climate sensor temperature entity
+      selector:
+        entity:
+          filter:
+            - device_class:
+              - temperature
+
+mode: queued
+
+variables:
+  climate_entity: !input radiator
+  temperature_entity: !input climate_sensor
+
+triggers:
+  - entity_id: !input climate_sensor
+    attribute: temperature
+    trigger: state
+
+conditions:
+  # We only want to execute the action if the temperature has changed by at
+  # least 0.1 degress C, according to the Zigbee2MQTT documentation for the
+  # device: https://www.zigbee2mqtt.io/devices/014G2461.html
+  #
+  # `external_measured_room_sensor` defaults to `-8000`, so this will work in
+  # all cases.
+  - condition: template
+    value_template: >-
+      {{
+        (
+         (
+          state_attr(climate_entity, 'external_measured_room_sensor') -
+           trigger.to_state.attributes.temperature * 100)
+          | abs)
+        >= 10
+      }}
+
+actions:
+  - variables:
+      # If we don't have a trigger ID the automation has been run manually, in
+      # which case we pull the temperature from the sensor instead of the
+      # trigger state.
+      external_temperature: >-
+        {% if trigger.id is not defined %}
+        {{ state_attr(temperature_entity, 'temperature') }}
+        {% else %}
+        {{ trigger.to_state.attributes.temperature }}
+        {% endif %}
+  - action: number.set_value
+    target:
+      entity_id: |-
+        number.{{ states[climate_entity].object_id }}_external_measured_room_sensor
+    data:
+      value: >-
+        {{
+          (external_temperature * 100) | int
+        }}