Long-range low-power electronic system for precision agriculture

Precision agriculture is one of the dominant fields in the food area where the requirement is to maximise the growth plant efficiency and to preserve natural resources as possible. A careful management of potable water, one of the earth resources, is the main key of the future of mankind. And the agriculture is the most thirsty economic sector with a big percentage of the total water footprint. In this context, this thesis is involved in the regional project WAPPFRUIT where smart technologies are applied to water management in fruit growing for rural development in Piedmont region. The main goal of WAPPFRUIT is the innovation of farms by means of cutting edge technologies that will let the correct definition of the water requirement and the complete automation of the micro-irrigation system. Through sensors, that measure water-involved physical quantities, the plants’ water requirement will be indirectly identified. Sensor data will be read automatically by a control unit, and an algorithm will activate a localized irrigation system when needed. As part of the work, an embedded electronic system was designed to collect environmental data (air temperature, air humidity and pressure) and soil data (soil water content and soil matric potential) to have punctual knowledge of water needs in orchards. A first step, it was to define requirements in terms of performance, standby consumption in a working scenario, low cost and communication protocol until to define an entire working system composed by several nodes where a front-end application can gather data from each of them. From a communication protocol point of view, it has been employed a radio procedure and it has been explained the reasons in the usage of the popular low cost radio communication protocol Long Range (LoRa) in the creation of a Low Power Wide Area Network (LPWAN), completely compliant with the concept of Internet of Things (IoT). All of these nodes was connected to a LoRa provider that allows to send basic commands to each node and to collect data on a cloud storage platform hence to be processed by an application subsequently. An investigation stage is followed to identify the best electronic and non-electronic components involved in the fabrication of the nodes thus to guarantee a proper protection from atmospheric agents as sunlight, rain, dust and cold. It has been realised a test firmware for a development board as a proof of concept of a single node, successively transferred on developed custom board with proper adjustments.