Homebridge Plugin for PMS7003

This is a Homebridge plugin for PMS7003 dust/particulate matter sensor, working on the Raspberry Pi 3 or Zero.

It uses read() and write() syscalls on the UART devices exposed by Linux's filesystem, and epoll to watch for messages on the UART file descriptor with a timeout.

Configuration

The PMS7003 must be connected to pins BCM14/BCM15 on a Raspberry Pi 3/Zero. Before running this plugin, you must add the homebridge user to the dialout group so Homebridge can access the serial port. sudo adduser homebridge dialout

Field name	Description	Type / Unit	Default value	Required?
name	Name of the accessory	string	—	Y
enableFakeGato	Enable storing data in Eve Home app	bool	false	N
fakeGatoStoragePath	Path to store data for Eve Home app	string	(fakeGato default)	N
enableMQTT	Enable sending data to MQTT server	bool	false	N
mqttConfig	Object containing some config for MQTT	object	—	N
showTemperatureTile	Enable showing temperature tile in Home that represents PM10	bool	false	N
showHumidityTile	Enable showing humidity tile in Home that represents 0.3µm-0.5µm particles	bool	false	N

If showTemperatureTile is true, a temperature tile will show up in Home with the PM10 in µg/m3. If showHumidityTile is true, a humidity tile will show up in Home with the number of particles of size 0.3-0.5µm in 0.1L of air, divided by 100 (i.e. 4% humidity = 400 particles).

The mqttConfig object is only required if enableMQTT is true, and is defined as follows:

Field name	Description	Type / Unit	Default value	Required?
url	URL of the MQTT server, must start with mqtt://	string	—	Y
PM1_0STopic	MQTT topic to which standard PM1.0 data is sent	string	PMS7003/PM1.0 Standard	N
PM2_5STopic	MQTT topic to which standard PM2.5 data is sent	string	PMS7003/PM2.5 Standard	N
PM10STopic	MQTT topic to which standard PM10 data is sent	string	PMS7003/PM10 Standard	N
PM1_0Topic	MQTT topic to which current PM1.0 data is sent	string	PMS7003/PM1.0	N
PM2_5Topic	MQTT topic to which current PM2.5 data is sent	string	PMS7003/PM2.5	N
PM10Topic	MQTT topic to which current PM10 data is sent	string	PMS7003/PM10	N
B0_3Topic	MQTT topic to which number of particles of size 0.3-0.5µm is sent	string	PMS7003/0.3	N
B0_5Topic	MQTT topic to which number of particles of size 0.5-1.0µm is sent	string	PMS7003/0.5	N
B1_0Topic	MQTT topic to which number of particles of size 1.0-2.5µm is sent	string	PMS7003/1.0	N
B2_5Topic	MQTT topic to which number of particles of size 2.5-5.0µm is sent	string	PMS7003/2.5	N
B5_0Topic	MQTT topic to which number of particles of size 5.0-10µm is sent	string	PMS7003/5.0	N
B10Topic	MQTT topic to which number of particles of size >10µm is sent	string	PMS7003/10	N

The difference between standard/current particle concentrations is that standard concentrations are scaled for ICAO standard atmosphere at sea level (i.e. 288.15K and 1013.25hPa).

Example Configuration

{
  "bridge": {
    "name": "Homebridge",
    "username": "XXXX",
    "port": XXXX
  },

  "accessories": [
    {
        "accessory": "PMS7003",
        "name": "Office PMS7003",
        "enableFakeGato": true,
        "showTemperatureTile": true,
        "showHumidityTile": true,
        "enableMQTT": true,
        "mqtt": {
            "url": "mqtt://192.168.0.38",
            "PM1_0STopic": "pms7003/PM1.0 Standard",
            "PM2_5STopic": "pms7003/PM2.5 Standard",
            "PM10STopic": "pms7003/PM10 Standard",
            "PM1_0Topic": "pms7003/PM1.0",
            "PM2_5Topic": "pms7003/PM2.5",
            "PM10Topic": "pms7003/PM10",
            "B0_3Topic": "pms7003/0.3",
            "B0_5Topic": "pms7003/0.5",
            "B1_0Topic": "pms7003/1.0",
            "B2_5Topic": "pms7003/2.5",
            "B5_0Topic": "pms7003/5.0",
            "B10Topic": "pms7003/10"
        }
    }
  ]
}

Project Layout

• All things required by Node are located at the root of the repository (i.e. package.json and index.js).
• The rest of the code is in src, further split up by language.
  • c contains the C code that runs on the device to communicate with the sensor. It also contains a simple C program that communicates with the sensor.
  • binding contains the C++ code using node-addon-api to communicate between C and the Node.js runtime.
  • js contains a simple project that tests that the binding between C/Node.js is correctly working. It also contains a characteristic that enables Eve to keep a historical graph of air quality.