The IAQ4Classroom Project aims to control, monitor and manage the air quality inside classrooms. For this, it was necessary to develop a cyber-physical system with certain sensors, capable of collecting data to quantify the air quality and then sending it, with the help of LoRaWAN technology, to the respective gateway and a priori to a server.
The three sensors used to measure and collect data were:

• DHT22 – A low-cost sensor that measures the relative humidity and temperature of indoor air;
• SPS30 – A PM sensor, it has a lower limit detection size of 0.3μg/m3 and allows the measurement of the mass of particles up to sizes PM1.0, PM2.5, PM4 and PM10, and the number of particles up to sizes PM0.5, PM1.0, PM2.5, PM4 and PM10;
• SGP30 – It is capable of detecting a wide variety of volatile organic compounds (VOCs), however, the sensor returns the value of the Total VOC (TVOC), and the carbon dioxide equivalent (eCO2), an indirect measure, that although not highly accurate, after calibration turns out to be a very reliable estimate;

A web application was developed using the FIWARE technology/framework, which makes the communication of IoT devices with the final interface more accessible. The main concept of the developed platform was to facilitate its use and make it more user-friendly for the end user. It is able to display the devices present in the school, as well as the floor plans of the same, and the device’s real-time data, it is also able to list all devices, being possible to edit and remove them. When creating a new device, all you need to do is assign a new ID, the floor and the coordinates on which it will be placed.