esp32-air-quality-sensor-mqtt

This is a version of my esp32-air-quality-reader that reads from a Plantower PMS5003 air quality sensor and publishes the results to an MQTT topic. It uses Peter Hinch's mqtt_as MicroPython library for MQTT functionality.

It reads the sensor every three minutes, warming it up for 30 seconds beforehand.

Setup

Create a file called config.json at the root of the src directory with the following contents:

{
    "client_id": "<MQTT client ID for the ESP32",
    "server": "<address of MQTT broker>",
    "port": 1883,
    "topic": "<MQTT topic to publish to>",
    "ssid": "<wifi network name>",
    "wifi_pw": "<wifi network password>"
}

You can optionally add the following to override the default library values of true for clean and clean_init:

    "clean": false,
    "clean_init": false,

Message content

Messages are published as stringified JSON in the following format:

{
    "pm_1_0": 0,
    "pm_2_5": 0,
    "pm_10": 0,
    "particles_0_3um": 0,
    "particles_0_5um": 0,
    "particles_1_0um": 0,
    "particles_2_5um": 0,
    "particles_5_0um": 0,
    "particles_10um": 0
}

On an Adafruit HUZZAH32, the red LED on the board will light up when it has connectivity to the MQTT broker and will go out when the connectivity stops.