Extract multiple json values from a dictionary?

Configuration
1

Hi all,

So I’m using the Platerecognizer integration and it’s publishing a MQTT payload like below to what looks like a dict to me?


{
  "plate_number": "CAM04",
  "score": 0.9,
  "frigate_event_id": "1709149025.353807-kftrt6",
  "camera_name": "front_driveway_2",
  "start_time": "2024-02-28 19:37:05"
}

How would I go about creating an MQTT sensor that incorporates all values?

Currently I have:


  - name: "License plate"
    state_topic: "frigate/platerecognizer"
    value_template: "{{ plate_number }}"
    #unit_of_measurement: "na"
    #json_attributes_topic: "na"
    icon: mdi:car

But it probably needs to be {{ json_value.plate_number }} and it also only gets that one value, whereas it would be helpful to get the other fields as well.

2

i believe you need to have an entry for each value.

mqtt:
  sensor:
    - name: "License plate"
      state_topic: "frigate/platerecognizer"
      value_template: "{{ json.plate_number }}"
    - name: "camera"
      state_topic: "frigate/platerecognizer"
      value_template: "{{ json.camera_name }}"

etc…
yes, this does risk race conditions where they can get mismatches.

typcially if you need them in sync, trigger off the mqtt trigger directly and use the data in the trigger event instead of reading the sensor.

if someone else knows a better way, i’d be interested too…

1 Like
3

Something like this should work.

  sensor:
    - name: ems_esp_thermostat
      state_topic: "ems-esp/thermostat_data"
      value_template: "{{ value_json.hc2.mode }}"
      json_attributes_topic: "ems-esp/thermostat_data"

One value of the json data will be the state of the sensor.
The other values will be attributes.

4

Cool.
So the value_json.hc2.mode, what does the hc2.mode signify ?
In my case can I then just use value_json.plate_number ?

5

Ah yes I forgot about Mqtt triggers. I might mess around with that. Ideally I do want to keep them synced up and make a history sensor out of it. Thanks.

6

It’s just an example.

value_template: "{{ value_json.plate_number }}"

should work for you.

1 Like
7

ah nice. learned something! thanks!

1 Like