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Template Sensor

The template sensor platform allows you to create a sensor with templated values using lambdas.

# Example configuration entry
sensor:
  - platform: template
    name: "Template Sensor"
    lambda: |-
      if (id(some_binary_sensor).state) {
        return 42.0;
      } else {
        return 0.0;
      }
    update_interval: 60s

Possible return values for the lambda:

  • return <FLOATING_POINT_NUMBER>; the new value for the sensor.
  • return NAN; if the state should be considered invalid to indicate an error (advanced).
  • return {}; if you don’t want to publish a new state (advanced).

Configuration variables

Section titled “Configuration variables”

  • lambda (Optional, lambda): Lambda to be evaluated every update interval to get the new value of the sensor

  • update_interval (Optional, Time): The interval to check the sensor. Set to never to disable updates. Defaults to 60s.

  • All other options from Sensor.

sensor.template.publish Action

Section titled “sensor.template.publish Action”

You can also publish a state to a template sensor from elsewhere in your YAML file with the sensor.template.publish action.

# Example configuration entry
sensor:
  - platform: template
    name: "Template Sensor"
    id: template_sens


# in some trigger
on_...:
  - sensor.template.publish:
      id: template_sens
      state: 42.0


  # Templated
  - sensor.template.publish:
      id: template_sens
      state: !lambda 'return 42.0;'

Configuration options:

  • id (Required, ID): The ID of the template sensor.
  • state (Required, float, templatable): The state to publish.

NOTE

This action can also be written in lambdas:

id(template_sens).publish_state(42.0);

Useful Template Sensors

Section titled “Useful Template Sensors”

Here are some useful sensors for debugging and tracking Bluetooth proxies.

# Example configuration entry
sensor:
  - platform: template
    name: "Bluetooth Proxy Connections Limit"
    id: bluetooth_proxy_connections_limit
    icon: "mdi:bluetooth-settings"
    update_interval: 30s
    entity_category: "diagnostic"
    lambda: |-
      int limit = bluetooth_proxy::global_bluetooth_proxy->get_bluetooth_connections_limit();
      ESP_LOGD("bluetooth_proxy_sensor", "Current connections limit => %d", limit);
      return limit;


  - platform: template
    name: "Bluetooth Proxy Connections Free"
    id: bluetooth_proxy_connections_free
    icon: "mdi:bluetooth-settings"
    update_interval: 30s
    entity_category: "diagnostic"
    lambda: |-
      int free = bluetooth_proxy::global_bluetooth_proxy->get_bluetooth_connections_free();
      ESP_LOGD("bluetooth_proxy_sensor", "Current connections free => %d", free);
      return free;

See Also

Section titled “See Also”