Design And Development of a Lora Communication System For Scalable Smart Irrigation Systems

Smart irrigation is a promising tool to optimize irrigation water use but is still faced with challenges related to usability and applicability attributed to several constraints such as high initial costs, complex user interface, poor connectivity, and limited farm coverage. This study aimed at solving these issues through development and testing of a LoRa communication system using a Raspberry Pi 4, LoRa HAT concentrator, and Strega smart valve. The study was conducted at the Makerere University Agricultural Research Institute Kabanyolo (MUARIK) [00°27'06.000" N, 32°03'60.240"]. The system design incorporates Chirpstack open source components including LoRa Network and application server for the scalable and license-free radio operation. A Strega smart valve was connected to the LoRa network server and ensured to be communicating before the system was then tested for the signal strength at two different locations in the site. Two parameters, the Signal to Noise Ratio (SNR) and Received Signal Strength Indicator (RSSI), obtained from the data packets received from the smart valve were compared to provide an analysis of the capability of the system to provide for efficient communication and automation of the drip irrigation. The valve communicated more efficiently and throughout the testing period while at a distance and elevation difference of 402m and 7.6m respectively, as compared to while at a distance and elevation difference of 660m and 8.5m. The reduced disruption in communication was attributed to the fewer obstructions present between the valve and antenna for the former as compared to the latter. The results show that to ensure proper communication between LoRa components, receiving antennas ought to be placed at the highest point in the field. They also illustrate the system’s capability to ensure efficient communication and automation of extensive and small smart irrigation systems as well as agricultural systems. This caters for poor connectivity and limited farm coverage as compared to other existing technologies such as Wi-Fi, Bluetooth and Zigbee. High initial costs are solved for as locally available materials are used in addition to the Chirpstacks application server which provides for the complex user interfaces due to its simplicity which in overall make the LoRa system ideal for Uganda’s current setting.