Our partner Thing Innovations are developing a number of air quality monitoring devices. The first of these is a portable CO2 monitor with GPS. This can be used to monitor CO2 levels not just outdoors but indoors too where the CO2 level will vary depending on occupancy and ventilation within the building.
This has been developed on the Thing Innovations/Herelab ENV platform using the Multitech mDot LoRaWAN module. The CO2 sensor uses Non-dispersive infrared (NDIR) absorption to determine the CO2 levels. The sensor normally uses a UART interface which is already being used by the GPS module so a custom developed I2C to UART board was created in collaboration with the engineers at Herelab. This particular sensor was chosen for its accuracy, response time and low power operation which is important for a battery operated device.
The device sends its location, temperature, humidity and CO2 level to our mapping application which can then be used to produce a heatmap showing CO2 concentrations. The device could be attached to a bicycle or backpack and the user cycles or walks an area to produce the data in real time providing there is a TTN gateway nearby. The data can also be logged to flash for off-line processing later.
