ESP8622 MQTT RGB LEDs Using JSON for Home Assistant

This project adds an easy way to create custom lighting for Home Assistant, an amazing, extensible, open-source home automation system.

I was frustrated that the built-in MQTT light didn't support transitions (fading between colors/brightnesses), and that it uses multiple separate calls to set the different values (state (on/off), brightness, color), so I decided to make my own version.

By sending a JSON payload (in an MQTT message), Home Assistant can include whichever fields are necessary, reducing the round trips from 3 to 1. For example, this is a sample payload including all of the fields:

{
  "state": "ON",
  "brightness": 120,
  "color": {
    "r": 255,
    "g": 100,
    "b": 100
  },
  "transition": 5
}

Installation/Configuration

To set this system up, you need to install and configure the custom component in Home Assistant and set up a light to control. This also assumes that you already have Home Assistant set up and running. If not, see the installation guides here.

The Home Assistant Side

1. Place the mqtt_json.py file in {HASS-CONFIG-DIRECTORY}/custom_components/light/, where {HASS-CONFIG-DIRECTORY} is your Home Assistant configuration directory. For a Raspberry Pi All-in-One install, this is /home/hass/.homeassistant/.

2. In your configuration.yaml, add the following:

   light:
     + platform: mqtt_json
       name: mqtt_json_light_1
       state_topic: "home/rgb1"
       command_topic: "home/rgb1/set"
       brightness: true
       rgb: true
       optimistic: false
       qos: 0

3. Set the name, state_topic, and command_topic to values that make sense for you.

4. Restart Home Assistant. Depending on how you installed it, the process differs. For a Raspberry Pi All-in-One install, use sudo systemctl restart home-assistant.service (or just restart the Pi).

The Light Side

I'm using ESP8266-01 microcontrollers for my lights because they are so cheap and small. The downside of the size and price is that programming them can be a bit of a hassle. There are many sites that go into detail, so I won't do it here. You'll need an ESP set up to work with the Arduino IDE. See the readme here for instructions.

1. Using the Library Manager in the Arduino IDE, install ArduinoJSON and PubSubClient. You can find the Library Manager in the "Sketch" menu under "Include Library" -> "Manage Libraries..."
2. Open the appropriate .ino file. For an RGB light, use mqtt_esp8266_rgb.ino. For a light that only supports brightness, use mqtt_esp8266_brightness.ino.
3. Set the pin numbers, WiFi SSID and password, MQTT server, MQTT username, and MQTT password to appropriate values.
4. Set the client_id variable to a unique value for your network.
5. Set light_state_topic and light_command_topic to match the values you put in your configuration.yaml.
6. Upload to an ESP with the correct connections.