MQTT Sensors - Espresense

I am really struggling to get MQTT sensors defined correctly. I have read all the documentation (several times) and most of the discussion on the Community.

I’m using Espresense and I can see the states of the device_trackers created by Espresense.

Using MQTT Explorer on a Windows laptop I can inspect the MQTT messages being received by HA

I’ve used an alias to translate the MAC address to an id so I can see the topic as
espresense/devices/car:merc/gate for example.

The value of the topic is:

  "name":"Car - Merc",

I have 4 Espresense sensors, one of which is gate, along my driveway and I want to detect the movement of the cars, so I am trying to extract the distance attribute for a car from each of the sensors.

I tried to create sensors in my configuration.yaml file as instructed in the manual.

  - name: 'Car - Merc - Gate'
    state_topic: 'espresense/devices/car:merc/gate/infojson'
    value_template: "{{ value_json.distance }}"
    unit_of_measurement: "m"
    state_attributes_topic: 'espresense/devices/car:merc/gate'
    payload_available: "online"
    payload_not_available: "offline"

I keep on getting the following error after a reboot.

I cannot see what I have done incorrectly. I saw some people using state_attribute_template but this does seem to be required, and that is not the error message.

I removed the state_attributes_topic from each of the sensors and they get created correctly, but the value returned is “unknown”.


There is no such option while defining a MQTT sensor

Unless the topic has a “retained” message, the sensor will only get a value the next time the topic is updated.