Airthings Wave Mini Sensor Reader

Airthings Wave Mini includes sensors for temperature, humidity and volatile organic compounds (VOC) measurements. Additionally, you can simply wave in front of the device to get a visual indication of your indoor air quality.

This is a project to provide users a starting point (read_wavemini.py) to read current sensor values from a Airthings Wave Mini devices using a Raspberry Pi 3 Model B over Bluetooth Low Energy (BLE).

Table of contents

• Airthings Wave Mini Sensor Reader
• Requirements
  • Setup Raspberry Pi
  • Turn on the BLE interface
  • Installing linux and python packages
  • Downloading script
• Usage
• Sensor data description
• Contribution
• Release notes

Requirements

The following tables shows a compact overview of dependencies for this project.

List of OS dependencies

OS	model/version	Comments
Raspbian	Raspberry Pi 3 Model B	Used in this project.
Linux	x86 Debian	Should work according to bluepy

List of linux/raspberry dependencies

package	version	Comments
python	2.7 or 3	Tested with python 2.7.13 and 3.7.3
python-pip		pip for python2.7
python3-pip		pip3 for python3
git		To download this project
libglib2.0-dev		For bluepy module

List of third-party Python dependencies

module	version
bluepy	1.3.0

Setup Raspberry Pi

The first step is to setup the Raspberry Pi with Raspbian. An installation guide for Raspbian can be found on the Raspberry Pi website. In short: download the Raspbian image and write it to a micro SD card.

To continue, you need access to the Raspberry Pi using either a monitor and keyboard, or by connecting through WiFi or ethernet from another computer. The latter option does not require an external screen or keyboard and is called “headless” setup. To access a headless setup, you must first activate SSH on the Pi. This can be done by creating a file named ssh in the boot partition of the SD card. Connect to the Pi using SSH from a command line interface (terminal):

$ ssh [email protected]

The default password for the pi user is raspberry.

Turn on the BLE interface

In the terminal window on your Raspberry Pi:

pi@raspberrypi:~$ bluetoothctl
[bluetooth]# power on
[bluetooth]# show
[bluetooth]# exit

After issuing the command show, a list of bluetooth settings will be printed to the Raspberry Pi terminal window. Look for Powered: yes.

Installing linux and python packages

Raspbian images usually comes with Python (2 and/or 3) pre-installed.

pi@raspberrypi:~$ python2 --version
pi@raspberrypi:~$ python3 --version

Install dependencies:

pi@raspberrypi:~$ sudo apt-get update && sudo apt-get install libglib2.0-dev git
# For Python 2
pi@raspberrypi:~$ sudo apt-get install python-pip 
pi@raspberrypi:~$ sudo pip2 install bluepy==1.3.0
# For python 3
pi@raspberrypi:~$ sudo apt-get install python3-pip
pi@raspberrypi:~$ sudo pip3 install bluepy==1.3.0

Downloading script

Downloading using git:

pi@raspberrypi:~$ sudo git clone https://github.com/Airthings/wavemini-reader.git

Downloading using wget:

pi@raspberrypi:~$ wget https://raw.githubusercontent.com/Airthings/wavemini-reader/master/read_wavemini.py

Usage

The general format for calling the script is as follows:

sudo python read_wavemini.py SERIAL_NUMBER SAMPLE_PERIOD [> somefile.txt]

After a short delay, the script will print the current sensor values to the Raspberry Pi terminal window. Optionally, you may pipe the readings to a text-file using > somefile.txt. Exit the script using Ctrl+C.

Positional input arguments	Type	Description
SERIAL_NUMBER	Integer	10-digit number found under the magnetic backplate of your Airthings product.
SAMPLE_PERIOD	Integer	Time in seconds between reading the current sensor values (excluding the overhead of connecting to target).

Example output:

Temperature: 27.33 *C, Humidity: 25.51 %rH, VOC: 48 ppm
Temperature: 27.33 *C, Humidity: 25.51 %rH, VOC: 48 ppm
Temperature: 27.33 *C, Humidity: 25.51 %rH, VOC: 48 ppm
Temperature: 27.33 *C, Humidity: 25.51 %rH, VOC: 48 ppm

Note: The scripts require that your device is advertising. If your device is paired/connected to e.g. a phone, you need to turn off bluetooth on your phone while using the scripts.

Note on choosing a sample period: Sensor values are updated every 5 minutes.

Sensor data description

sensor	units
Temperature	°C
Humidity	%rH
VOC	ppm

Contribution

Let us know how it went! If you want contribute, you can do so by posting issues or suggest enhancement here.

Release notes

Initial release 2-June-2020