--- layout: page title: "Template Sensor" description: "Instructions on how to integrate Template Sensors into Home Assistant." date: 2016-01-27 07:00 sidebar: true comments: false sharing: true footer: true ha_category: Sensor ha_release: 0.12 ha_iot_class: "Local Push" logo: home-assistant.png ha_qa_scale: internal --- The `template` platform supports sensors which break out `state_attributes` from other entities.
If you do not supply an `entity_id` in the configuration you will need to run the service `homeassistant.update_entity` to update the sensor.
## {% linkable_title Configuration %} To enable Template Sensors in your installation, add the following to your `configuration.yaml` file: {% raw %} ```yaml # Example configuration.yaml entry sensor: - platform: template sensors: solar_angle: friendly_name: "Sun angle" unit_of_measurement: 'degrees' value_template: "{{ states.sun.sun.attributes.elevation }}" sunrise: value_template: "{{ states.sun.sun.attributes.next_rising }}" ``` {% endraw %} {% configuration %} sensors: description: List of your sensors. required: true type: map keys: friendly_name: description: Name to use in the frontend. required: false type: string friendly_name_template: description: Defines a template for the name to be used in the frontend (this overrides friendly_name). required: false type: template entity_id: description: The template engine will attempt to work out what entities should trigger an update of the sensor. If this fails to get the correct list (for example if your template loops over the contents of a group) then you can provide a list of entity IDs that will cause the sensor to update. required: false type: string, list unit_of_measurement: description: "Defines the units of measurement of the sensor, if any. This will also influence the graphical presentation in the history visualisation as continuous value. Sensors with missing `unit_of_measurement` are showing as discrete values." required: false type: string default: None value_template: description: Defines a template to get the state of the sensor. required: true type: template icon_template: description: Defines a template for the icon of the sensor. required: false type: template entity_picture_template: description: Defines a template for the entity picture of the sensor. required: false type: template device_class: description: Sets the class of the device, changing the device state and icon that is displayed on the UI (see below). It does not set the `unit_of_measurement`. required: false type: device_class default: None {% endconfiguration %} ## {% linkable_title Considerations %} If you are using the state of a platform that takes extra time to load, the Template Sensor may get an `unknown` state during startup. To avoid this (and the resulting error messages in your log file), you can use `is_state()` function in your template. For example, you would replace {% raw %}`{{ states.switch.source.state == 'on' }}`{% endraw %} with this equivalent that returns `true`/`false` and never gives an `unknown` result: {% raw %}`{{ is_state('switch.source', 'on') }}`{% endraw %} ## {% linkable_title Examples %} In this section you find some real-life examples of how to use this sensor. ### {% linkable_title Sun Angle %} This example shows the sun angle in the frontend. {% raw %} ```yaml sensor: - platform: template sensors: solar_angle: friendly_name: "Sun Angle" unit_of_measurement: '°' value_template: "{{ '%+.1f'|format(states.sun.sun.attributes.elevation) }}" ``` {% endraw %} ### {% linkable_title Renaming Sensor Output %} If you don't like the wording of a sensor output then the Template Sensor can help too. Let's rename the output of the [Sun component](/components/sun/) as a simple example: {% raw %} ```yaml sensor: - platform: template sensors: sun_state: friendly_name: "Sun State" value_template: >- {% if is_state('sun.sun', 'above_horizon') %} up {% else %} down {% endif %} ``` {% endraw %} Processes monitored by the [System Monitor sensor](/components/sensor.systemmonitor/) show `on` or `off` if they are running or not. This example shows how the output of a monitored `glances` process can be renamed. {% raw %} ```yaml sensor: - platform: template sensors: glances: friendly_name: "Glances" value_template: >- {% if is_state('sensor.process_glances', 'on') %} running {% else %} not running {% endif %} ``` {% endraw %} The [Template Binary Sensor](/components/binary_sensor.template/) is the one in similar cases if you prefer to see an icon instead of text. ### {% linkable_title Multiline Example With an `if` Test %} This example shows a multiple line template with an `if` test. It looks at a sensing switch and shows `on`/`off` in the frontend. {% raw %} ```yaml sensor: - platform: template sensors: kettle: friendly_name: "Kettle" value_template: >- {% if is_state('switch.kettle', 'off') %} off {% elif states.switch.kettle.attributes.kwh|float < 1000 %} standby {% elif is_state('switch.kettle', 'on') %} on {% else %} failed {% endif %} next_sensor: ... ``` {% endraw %} ### {% linkable_title Change The Unit of Measurement %} With a Template Sensor it's easy to convert given values into others if the unit of measurement doesn't fit your needs. {% raw %} ```yaml sensor: - platform: template sensors: transmission_down_speed_kbps: friendly_name: "Transmission Down Speed" unit_of_measurement: 'kB/s' value_template: "{{ states('sensor.transmission_down_speed')|float * 1024 }}" transmission_up_speed_kbps: friendly_name: "Transmission Up Speed" unit_of_measurement: 'kB/s' value_template: "{{ states('sensor.transmission_up_speed')|float * 1024 }}" ``` {% endraw %} ### {% linkable_title Change The Icon %} This example shows how to change the icon based on the day/night cycle. {% raw %} ```yaml sensor: - platform: template sensors: day_night: friendly_name: "Day/Night" value_template: >- {% if is_state('sun.sun', 'above_horizon') %} Day {% else %} Night {% endif %} icon_template: >- {% if is_state('sun.sun', 'above_horizon') %} mdi:weather-sunny {% else %} mdi:weather-night {% endif %} ``` {% endraw %} ### {% linkable_title Change The Entity Picture %} This example shows how to change the entity picture based on the day/night cycle. {% raw %} ```yaml sensor: - platform: template sensors: day_night: friendly_name: "Day/Night" value_template: >- {% if is_state('sun.sun', 'above_horizon') %} Day {% else %} Night {% endif %} entity_picture_template: >- {% if is_state('sun.sun', 'above_horizon') %} /local/daytime.png {% else %} /local/nighttime.png {% endif %} ``` {% endraw %} ### {% linkable_title Change the Friendly Name Used in the Frontend %} This example shows how to change the `friendly_name` based on a date. Explanation: We add a multiple of 86400 seconds (= 1 day) to the current unix timestamp to get a future date. {% raw %} ```yaml sensor: - platform: template sensors: forecast_1_day_ahead: friendly_name_template: >- {%- set date = as_timestamp(now()) + (1 * 86400 ) -%} {{ date|timestamp_custom("Tomorrow (%-m/%-d)") }} value_template: "{{ sensor.darksky_weather_forecast_1 }}" forecast_2_days_ahead: friendly_name_template: >- {%- set date = as_timestamp(now()) + (2 * 86400 ) -%} {{ date|timestamp_custom("%A (%-m/%-d)") }} value_template: "{{ sensor.darksky_weather_forecast_2 }}" ``` {% endraw %} This example shows how to change the `friendly_name` based on a state. {% raw %} ```yaml sensor: - platform: template sensors: net_power: friendly_name_template: >- {% if states('sensor.power_consumption')|float < 0 %} Power Consumption {% else %} Power Production {% end %} value_template: "{{ states('sensor.power_consumption') }}" unit_of_measurement: 'kW' ``` {% endraw %} ### {% linkable_title Working with dates %} The `template` sensors are not limited to use attributes from other entities but can also work with [Home Assistant's template extensions](/docs/configuration/templating/#home-assistant-template-extensions). This template contains no entities that will trigger an update, so either we need to use `homeassistant.update_entity` or add an `entity_id:` line for an entity that will force an update - here we're using `sensor.date`. {% raw %} ```yaml sensor: - platform: template sensors: nonsmoker: value_template: '{{ (( as_timestamp(now()) - as_timestamp(strptime("06.07.2018", "%d.%m.%Y")) ) / 86400 ) | round(2) }}' entity_id: sensor.date friendly_name: 'Not smoking' unit_of_measurement: "Days" ``` {% endraw %} Useful entities to choose might be `sensor.date` which update once per day, or `sensor.time` which updates once per minute. Note: If a template uses more than one sensor they can be listed The alternative to this is to create an `Automation`using the new (81.0) service `homeassistant.update_entity` and list all entity's requiring updates and setting the interval based on time. {% raw %} ```yaml automation: - alias: 'nonsmoker_update' trigger: - platform: time minutes: '/1' action: - service: homeassistant.update_entity entity_id: sensor.nonsmoker ``` {% endraw %}