About us

The team behind this project is small but enthusiastic. Some would say it's a "one-man band", but it wouldn't be fair to friends and colleagues who contributed to the creation of this portal, both conceptually and also materially (granted space, Raspberry Pi computers...). The project was born out of a hobby, excess free time, and as an escape from daily stress.

Project Sensorbox

The Sensorbox project started at the end of 2021, motivated by the often bad air of a small Croatian city - Varaždin, and the lack of an official air quality sensor (Particulate Matter - PM 2.5 and PM 10), we decided to buy particle sensor and connect it to an unused Raspberry Pi computer. That's when everything started, from the first static html page on a local server to the portal with up-to-date data in real-time for several cities across Croatia.
This is just the beginning since the portal as such is far from finished.

Among the available stations that measure air quality are: Zagreb, Varaždin, and Čabar. The air quality may vary due to various meteorological and microclimatic factors, and for this reason - in addition to air quality, we also measure temperature, pressure, and humidity, which gives us a broader picture and an insight into air quality trends (concerning the listed meteorological factors). All data is recorded in the database and an archival review is available from the first moment when air quality measurements began. There is a tabular representation of the data along with the graph. The graph also makes it possible to observe the trends in air quality for the selected period. The given data is possible to sort and filter.

Our goals

In order to get a better and more relevant picture of the actual air quality situation in Croatia and Croatian cities, our goal is to expand the network of stations and use existing publicly available data on air quality. The point of the portal is not to scare anyone or to point a finger at anyone, but rather to indicate the problem if the problem exists.
The consequences of impure air are visible and measurable, but also accumulative, which means that children are the most vulnerable group.

Data

This is an amateur project and all data comes from amateur sensors and homemade stations, therefore, it should not be a benchmark for anyone citing it as a single source of data due to possible deviations. For precise numbers, there are government institutions that use industrial-grade quality sensors that are regularly maintained and calibrated. The sensor numbers of this project may indicate a possible problem and air pollution with particles of 2.5 and 10 microns, especially in locations that do not have such a sensor (Varaždin only received a small particle sensor at the end of November 2022).
If we want to ensure decent air quality, we need as many sensors as possible, in every city and several locations of every city, especially in residential areas, so that they can indicate a problem if it exists.
In an ideal world, there should be no need for sensors or such a project.

Technology

The measuring stations consist of a Raspberry Pi computer with sensors for PM 2.5 and PM 10 particles (Nova PM sensor SDS011) and a temperature, pressure, and humidity sensor (BME280).
Each measurement is carried out in an interval of 2-3 minutes in a cycle of 15 measurements within 15 seconds (with CRC checking of the value of the sensor itself) and the average of these values is taken. Sensors and stations are protected from cold, wind, sun, rain, and snow.