Temperature unit conversions are moving from the Entity base class to the SensorEntity base
class. Unit conversions will only be done if the sensor's device_class attribute is set
to DEVICE_CLASS_TEMPERATURE. If the device_class is not set or is not set to
DEVICE_CLASS_TEMPERATURE temperature conversion will take place during a transition
period and a warning will be logged.
To facilitate this, the sensor entity model has been updated with two new properties,
native_value and native_unit_of_measurement. This allows us to add additional
unit conversions in the future instead of relying on the integrations to do it themselves.
Sensor implementations should no longer implement the state() property function or set
the _attr_state attribute. Sensor implementations should also not implement the
unit_of_measurement property function, set the _attr_unit_of_measurement attribute
or set the unit_of_measurement member of EntityDescription.
native_value
The value reported by the sensor.
The actual state written to the state machine may be modified by SensorEntity due to
unit conversions.
native_unit_of_measurement
The unit of measurement of the sensor, if any.
The unit_of_measurement written to the state machine may be modified by SensorEntity
due to unit conversions.