Sensing particulate matter where it really matters.

prototype built by the sense10 team @cyclehackBER

Some background

Ben and I have developed a prototype that measures distance with a simple Arduino platform distance sensor. The data then gets uploaded to a TTN backend via the LoRa protocol. Through a Node.js API we make use of the data by simply displaying a SVG that changes its state when the distance changes. This happens in real time and is mobile. We attached a 9v power source to this setup and took it for a walk. Because of our TTN gateway we placed at the window the coverage of the LoRaWAN is good enough to have a stable upload while moving many kilometers away from our gateway.

Developing Environment

code snippet from the .ino file

To make it easy for everyone to understand or even contribute to this project we uploaded the code to Github. The initial setup is quite complex but it’s definitely worth the effort. Once you have the setup running you are able to create awesome IoT products that work independently from any WiFi sources. Put it everywhere in the range of a running TTN gateway and your imagination is the only limit. We decided to make use of it by sensing particulate matter.

Why particulate matter?

Since we are facing many challenges regarding air pollution in big cities it’s important to actually show everyone what’s going on. Using data to communicate the problems is an important step to initiate next steps to eventually make our all lives a little healthier. In Germany the Umweltbundesamt provides a data platform where one can download all the data from the static monitoring stations in Germany. In 2016 there are almost 350 stations measuring PM10, PM2,5 and the NO2 pollution. Another great project comes from Stuttgart. not only provides data, collected by citizen and visualized on a map. They also are providing a toolkit for building your own PM sensor.

pm10 data in real time on a map projection

Our goal

It’s great seeing all the efforts towards making health related issues more transparent. Visualizing the data can help to communicate the problems to citizens and politicians. Both sure have interests in recognizing the challenges to take the next steps and eventually do countermeasures.

With Sense10 we are taking the particulate matter sensing to the next level by enabling people carrying the sensors with them. We want you to attach the Airrohr on your bicycle or stroller or backpack. We want you to measure particulate matter where you go. We think this is an important information we need to communicate. We want to answer the question:

How is the individual citizen affected by air pollution on a daily basis?

Urban Image by Gabriel Santiago taken from

Did you know?

Let’s quickly recap what several recent studies and papers say about air pollution and learn what projects exists that helping people making an impact.

In its factsheet from 2016 the World Health Organisation is providing some interesting key facts:

  • Air pollution is a major environmental risk to health. By reducing air pollution levels, countries can reduce the burden of disease from stroke, heart disease, lung cancer, and both chronic and acute respiratory diseases, including asthma.
  • The lower the levels of air pollution, the better the cardiovascular and respiratory health of the population will be, both long- and short-term.
  • The “WHO Air quality guidelines” provide an assessment of health effects of air pollution and thresholds for health-harmful pollution levels.
  • In 2014, 92% of the world population was living in places where the WHO air quality guidelines levels were not met.
  • Ambient (outdoor air pollution) in both cities and rural areas was estimated to cause 3 million premature deaths worldwide in 2012.
  • Some 88% of those premature deaths occurred in low- and middle-income countries, and the greatest number in the WHO Western Pacific and South-East Asia regions.
  • [..]

This paper from the European Commission states that

Reducing global particulate matter pollution could save millions of lives


Globally, more than 3.2 million premature deaths per year are attributed to exposure to ambient fine particulate matter (PM2.5). A new study estimates that 2.1 million premature deaths could be avoided if countries achieved the WHO guideline for PM2.5. Even meeting their closest WHO interim concentration targets could avoid 750 000 (23%) deaths attributed to PM2.5 per year.

Awesome people making awesome stuff

Cyclehack Berlin

Yay! Group effort. Within the two days of the Cyclehack Berlin we developed a functional prototype which measures the air quality while being mobile on a bike. The idea was to combine the Airrohr from the initiative with the LoRaWAN technology. We now sending the exact location of the LoRa Node in combination with the measurement data from the NovaPM10 sensor. This then gets visualized on a map to enable people to watch where a bicyclist gets into trouble in terms of air quality.

The team, consisting of Hannes, Joscha, Til, Jannis and me, has been incredible productive throughout the whole Cyclehack.

When eating an elephant take one bite at a time

We figured it would be helpful to segment the whole project into smaller steps so that everyone involved can easily choose what he would like to work on. Friday was pitch day. The idea was already clear to me. I just had to present it in a understandable manner so I could inspire as many people as possible. The team formed quickly and we were ready to start. First I quickly explained what LoRa is and does and then segmented the whole work into smaller steps.

First step was to get sensor data from the NovaPM10 Sensor. Since this was originally build to transmit data via WiFi we had no use for the pre-installed program on the board.

Two nodes, double the fun

We then used the GPS module to track the location of the nodes. A blinking blue light indicates that the node has a steady connection to at least three GPS satellites.

Third step was combining the PM10 sensory data and the GPS location data and transmitting the whole package via the LoRa protocol to the TTN. We were very fortunate to actually get a connection from the FabLab to the Central Station LoRa Gateway, which is operated by the DB Systel. (Thanks for that!)

With Mapbox we then made the whole data visible to everyone. The map we developed shows location and air quality data live from the box’ current location. The time slider on the bottom gives access to some recent history data.

Since the whole technical setup is kind of fragile and definitely would be outside most of the time, we quickly created a box and laser cutted it. This is not only helpful for protection from wind and weather it also looks cool. We also engraved our logo on the transparent roof. (Which I quickly made on the train ride)

What do you think? Not bad for a hack, eh?

Demo time

After a short introduction into why we are doing this and how, we demonstrated the prototype. Unfortunately we did not had enough time to get around the city to gather more data. We only took a quick ride to the Alexanderplatz and back, that already revealed some issues. First we need to know what the threshold of the measurement data is. We tested it with a diesel car parked outside and noticed that the data only showed small changes. So there is still some work to do.

photograph by Matthias Grytzka

Summary and a Thank you

We took the NovaPM10 sensor from the Airrohr and changed the data transmitting technology from WiFi to LoRa to enable people sensing the air quality where it really matters: where people are. The LoRaWAN technology enables us to transmit small amount of data without an internet connection. The data then gets visualized live on a map. The setup got a nice box that is ready to go and that’s it.

The Code for the arduino setup and the web backend is open source and available at Github and Github.

We want to thank the entire Cyclehack Berlin Team for making this a great event.

You can see many more Hacks on the global Hack-Catalogue.