Design and implementation of a low-cost IoT-based agroclimatic monitoring system for greenhouses

Climate change is one of the main factors causing environmental variations that affect the crops in agriculture worldwide. These variations are expected to not only continue, but also to increase, putting future agricultural production and food security at risk. In this work, an agroclimatic monitoring system for greenhouses composed of three main parts: monitoring stations, a wireless communication network, and a data processing and visualization platform is proposed. The aim of this work is to provide a technological solution based on the Internet of Things (IoT) that helps the agricultural sector to avoid crop losses due to climate change. The proposed system consists of several monitoring stations inside and outside the greenhouse, with multiple sensors to measure temperature, relative humidity, soil humidity, wind speed, wind direction, precipitation, radiation, pH, and electroconductivity. The information generated by the sensors is pre-processed and temporarily stored in the LinkIt Smart 7688 Duo microcontroller. Then, this information is sent via wireless through the inbuilt Wi-Fi module of the stations to the Thinger.io platform, where the data is processed, analyzed, and presented in real time in graphical form. Authorized users have access to this platform and can visualize the collected data from any electronic device with Internet access, following protocols to guarantee the security of the system. Using open hardware and open-source tools, and based on the IoT concept, a low-cost greenhouse monitoring system with six internal monitoring stations, one external monitoring station, and one portable monitoring station, that costs US, 180.00 was implemented. The results show that the total energy consumption of the system is approximately 20W, with a very good performance in terms of sampling time. This system was implemented in a 5000 square meter greenhouse with melon crops, where tests to evaluate the network performance within each zone in the greenhouse allowed us to consider WiFi technology to improve network coverage. Also, maximum, minimum, and average measurement values were evaluated to determine the critical levels recorded by the different sensors of agroclimatic variables during the period of study. The proposed system demonstrated to provide the agricultural sector with a low-cost, efficient, and easy-to-use tool to monitor agroclimatic variables in greenhouses that can help to prevent undesired climatic variations in advance, thus guaranteeing adequate conditions and reducing losses in production.