Manually add MQTT Entities

123 · January 6, 2021, 3:52pm

1. Create an MQTT Light using a script

Assuming you have an existing scripts.yaml file, paste this into it and save the file:

Click to reveal scripts

## MQTT Discovery Test
  example_create:
    alias: 'Example MQTT Light - Create'
    sequence:
      service: mqtt.publish
      data:
        topic: 'homeassistant/light/example/config'
        retain: true
        payload: >
          {
            "name": "Example",
            "unique_id": "ABC123",
            "stat_t": "home/example",
            "cmd_t": "home/example/set",
            "bri_stat_t": "home/example/brightness",
            "bri_cmd_t": "home/example/brightness/set"
          }

  example_delete:
    alias: 'Example MQTT Light - Delete'
    sequence:
      service: mqtt.publish
      data:
        topic: 'homeassistant/light/example/config'
        retain: true
        payload: ''

Then carry out the following simple steps

Execute Configuration > Server Controls > Check Configuration and confirm it reports no errors.
Execute Configuration > Server Controls > Reload Scripts
Execute Configuration > Scripts > Example MQTT Light - Create

Congratulations! You have used a script to create an MQTT Light via MQTT Discovery.

2. Control/remove the light

If you check Developer tools > States, you will find a new entity named light.example and its state will be off.

To turn on light.example, publish ON to home/example.
To change its brightness, publish 125 to home/example/brightness
To remove light.example from your system, execute:
Configuration > Scripts > Example MQTT Light - Delete

3. Advantages of this method

One of the advantages (compared to manually defining MQTT entities in YAML) is that you don’t need to restart Home Assistant to add/remove MQTT entities. Another advantage is that you can define Devices using MQTT Discovery but cannot do that via YAML.

Here’s an example of what I mean. The following script defines a switch. However, I want the switch to be represented as an entity of a device called “X10 CM11A”. Notice the additional “device” information included in its discovery payload (you can’t do that if you were to define the switch in YAML).

      - service: mqtt.publish
        data:
          topic: homeassistant/switch/pool_pump/config
          retain: true
          payload: >
            {
              "name": "Pool Pump",
              "state_topic": "home/pump/powerstate",
              "command_topic": "command/pump/powerstate",
              "payload_on": "1",
              "payload_off": "0",
              "state_on": "1",
              "state_off": "0",
              "unique_id": "x10_pool_pump_switch",
              "device": {
                  "identifiers": ["x10"],
                  "name": "X10 CM11A",
                  "model": "CM11A",
                  "manufacturer": "X10",
                  "sw_version": "1.X"
              }
            }

The result will be the creation of a Device called “X10 CM11A” and “Pool Pump” is one of the several entities belonging to it.