MQTT sensor with changing fields

Configuration
1

I have created the following MQTT Sensor:

 - platform: mqtt
   name: "Meter Power"
   state_topic: "power/#"
   qos: 0
   unit_of_measurement: "W"
   value_template: "{{value_json.power }}"

below are some example values I am receiving. What would be the correct way to parse them?

{"time": 1575888977.0, "power": 195.0}
{"time": 1575888984.0, "power": 199.0}
{"time": 1575631237.0, "price": 0.0, "tier": 0}
{"time": 1575888992.0, "power": 199.0}
{"time": 1575889000.0, "power": 197.0}

The sensor is updated but sometimes is empty (I guess when power is not one of the keys in the sensor data.

2

What do you want the sensor to show? The power? Do you just want to show 0 instead of an empty field in case there is now power reading?

3

I am only really interested in the time and the power usage. (I probably dont even need the time)

4

Then your code is correct. Do you just want to show 0 instead of an empty field or what is your issue?

5

If the payload contains power this template will report it as the sensor’s new state otherwise it will report the sensor’s existing state.

 - platform: mqtt
   name: "Meter Power"
   state_topic: "power/#"
   qos: 0
   unit_of_measurement: "W"
   value_template: >
     {{ value_json.power if value_json.power is defined else states('sensor.meter_power') }}
1 Like
6

Thanks for your help. would like the last value as per Taras solution

7

Thanks. Thats exactly what I was looking for but just didnt know :slight_smile:

1 Like