homebridge-airrohr

HomeBridge module for the DIY luftdaten.info air particulates sensor from OpenData Stuttgart.

It can be used to see the status of your own sensor in HomeKit. You can also use it to see another sensor if its data is published to data.sensor.community (see here for more info).

Features

• See air quality (incl. particulates values for PM10 and PM2.5), temperature and humidity in HomeKit and the Home app
• Get the data from a sensor on your local network
• Get the data from public sensor on data.sensor.community
• See history for temperature, etc. using the Elgato Eve app
• Supported sensors / combinations :
  • SHT3X (temperature & air quality)
  • DHT22 + BMP280 (temperature & air quality)
  • SDS011 (temperature & air quality)
  • and adding more is simple as long as you get the data as JSON via HTTP

Setup

First follow the instructions for HomeBridge.

Install homebridge-airrohr using (sudo) npm install -g homebridge-airrohr.

Configure your AirRohr sensor in the homebridge settings file. See config.sample.json. All settings except update_interval_seconds (defaults to 120 seconds) and history (defaults to persisting to memory) are required.

See the documentation of the fakegato-history module for the list of supported options.

To run this project you have two options

Option A: The sensor & homebridge in your (home) network

To do this set json_data to

http://feinstaubsensor-<YOUR_SENSOR_ID>.local/data.json

using the same local network as your sensor.

Note: If you use a HomeKit hub (like a Apple TV or a iPad) you can still access your data from outside your home. See Apple's documentation for details.

Don't set public_temperature_json_data or public_airquality_json_data in this scenario.

Option B: Use the luftdaten.info API

This allows you to add any sensor not only your own. To get the same functionality as above you need to set two IDs/URLs:

• Set public_temperature_json_data to the URL where to find the temperature data: http://data.sensor.community/airrohr/v1/sensor/<YOUR_TEMPERATURE_SENSOR_ID>/

• Set public_airquality_json_data to the URL where to find the air particulates (PM10, PM25) data: http://data.sensor.community/airrohr/v1/sensor/<YOUR_AIRQUALITY_SENSOR_ID>/

Don't set json_data in this scenario.

Note: If you set json_data the public_… settings will be ignored.

Advanced configuration

Disabling sensors

You can disable several characteristics by setting:

• "disable_humidity": true
• "disable_temperature": true
• "disable_pressure": true
• "disable_pm25": true
• "disable_pm10": true

in the config file. Note that if you disable temperature pressure will also not be disanbled.

Configuring alert limits

The warning levels are calculated at <=40% -> EXCELLENT, <=60% -> GOOD, <=80% -> FAIR, <=100% -> INFERIOR, >100% -> POOR quality.

The basis for this calculation is the average of the percentage of a daily maximum limit for PM10 and PM2,5. These limits default to 50 µg/m³ and 25 µg/m³ respectivly. However these can be adjusted in the config as well. See the sample config for this.

Demo