Sensor Template | use backup sensor if main not available

Configuration
#1

I have a BLE sensor attached to a remote HA instance which sometimes times out. When this happens, I want to use the main HA instance (provided the BLE sensor is in range) to show the BLE value.

I have seen many contradicting examples over this forum and reddit but none seem to work for me… I have tried == none None unknown Unknown unavailable Unavailable and nothing works for me. In HA Lovelace is shows as Unknown

What is the correct syntax?

configuration.yaml

sensor:
  temperature_kitchen:
        friendly_name: 'Kitchen Temperature'
        unit_of_measurement: °C
        value_template: >
          {% if states('sensor.pz_ble_temperature_kitchen') == "Unknown" %}
            {{states('sensor.ble_temperature_kitchen')}}
          {% else %}
          {{states('sensor.pz_ble_temperature_kitchen')}}
          {% endif %}
#2

If it indicates Unknown in the Lovelace UI then in Developer Tools > States it will be displayed as unknown (all lowercase) which is its actual state value.

sensor:
  - platform: template
    sensors:
      temperature_kitchen:
        friendly_name: Kitchen Temperature
        unit_of_measurement: "°C"
        value_template: >
          {% set t1 = states('sensor.pz_ble_temperature_kitchen') %}
          {% set t2 = states('sensor.ble_temperature_kitchen') %}
          {{ t2 if t1 == 'unknown' else t1 }}

Legacy Template Sensor Configuration Format

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#3

Oh, that worked! Thanks Taras!

#4

You’re welcome!

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#5

If I wanted to set an attribute to show with the state was coming from Sensor A or B… how would I incorporate that? Thanks in advance!

#6 
sensor:
  - platform: template
    sensors:
      temperature_kitchen:
        friendly_name: Kitchen Temperature
        unit_of_measurement: "°C"
        value_template: >
          {% set t1 = states('sensor.pz_ble_temperature_kitchen') %}
          {% set t2 = states('sensor.ble_temperature_kitchen') %}
          {{ t2 if t1 == 'unknown' else t1 }}
        attribute_templates:
          source: >-
            {% set t1 = states('sensor.pz_ble_temperature_kitchen') %}
            {% set t2 = states('sensor.ble_temperature_kitchen') %}
            {{ 'B' if t1 == 'unknown' else 'A' }}
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#7

Legend, thank you.

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#8

Say Taras… you’re kinda smart… is it possible to set up sensors something like this? Or not possible with sensors…?

ble_sensors = {‘kitchen’ : ‘pz_ble_temperature_kitchen’, ‘ble_temperature_kitchen’, ‘ben’ : ‘sensor.pz_ble_temperature_ben’, ‘sensor.ble_temperature_a4c13825e91f’ }
for name in ble_sensor.name():

and set up the friendly name and sensor 1 and 2?

#9

Use friendly_name_template (instead of friendly_name) with the same template that was used for attribute_templates in the previous example.

1 Like