BioSense’s Group for Sensor Design focuses on development of sensing devices based on optical, physical and electromagnetic properties of the surroundings. These measurements, however, have to be delivered and presented to the user, so that he could make optimal decisions on them. Key ingredient for that is communications layer of IoT technology that deals with interoperability issues in order to support devices communication and enables the data exchange between heterogeneous field sensors and management information systems.
One of the goals of IoT research at BioSense is to enable communication of sensors with other devices. These devices fall into two groups. The first consists of machine-to-machine communication devices, such as base stations and gateways. An example of this is the add-on for the 500 weather stations that BioSense will deploy across Serbia. It enables them to be integrated to the LoRa network and gather spatially precise measurements of weather parameters. The second group consists of mobile phones and tablets, that is, the devices for direct presentation of the results to the user. An example of this is the communication pipeline developed for Plant-O-Meter device that senses the reflectance from the plant canopy in four bands (blue, green, red and near infrared). Here, the aim was to transfer the data processing from the sensor to the mobile phone and further to the server with geo-database for storing processed data. The solution utilizes two network connectivity types (Bluetooth and Wi-Fi) to enable capturing and transmitting geo-localised real-time information. Established connection layer transmits raw measurements of spectral reflectance to mobile phone where vegetation indexes are calculated. Along with GPS location calculated indexes are further forwarded to the server. Bluetooth interface for sensor – mobile phone connection had a huge influence on lowering the price of the IoT solution.