6th March 2019
Optimizing building conditions is a challenge for many modern companies. It not only helps to reduce company operating costs but also benefits the health and productivity of the occupants, as well as the natural environment.
This issue also concerned a customer, who asked us to provide a tool for measuring air quality in the office. Our goal was to obtain measurements of humidity, temperature and carbon dioxide levels.
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Technology in air quality monitoring
Our primary goal was to create a prototype as quickly and efficiently as possible.
That’s why we used ready-made sensor modules, which we already had in the laboratory:
Bosch BME280 – for measuring temperature, humidity and pressure, and DFRobot CO2 Sensor hooked up to the ADC ADS1015 – Adafruit module.
As one of our priorities was to achieve the fastest possible results, we used Raspberry Pi 3B+.
To simplify the system architecture, we’ve installed the Node-RED environment, the Mosquito MQTT Broker and the MySQL database on the central unit.
The other devices were only to publish data using the MQTT protocol to the central unit.
After installing all the required packages and running the Node-Reda application, we were able to proceed with the configuration.
In the system, we defined a simple flow, thanks to which it is possible to read the transmitted data, transfer them to the created database and view on dashboards.
Then we created the data sources. For this purpose, we wrote a simple script in Python, which accessed the sensors and routed the collected data to our MQTT broker in JSON format.
Additionally, we defined a module in the “flow” which enables seeing data insights entering the system. This allowed us to verify the correct decoding of our data format.
These activities made it possible to display on the dashboard all collected information from the period defined in the configuration.
The MySQL database used in the project enables exporting data from any period.
Results and next steps
What results have we achieved with these technologies and methods? The whole project has become a handy tool for monitoring indoor air quality.
But that’s not all. We still have to design and print the case for the device.
However, we saved the best point for last. The project turned out to be really “rapid”! It only took us a few hours to assemble the entire system, launch it and collect the first data!