Development of microcontroller-based data logger for real-time monitoring of drying and storage of food grains

Food grains are harvested at higher moisture content to avoid losses during harvesting. Temperature and relative humidity are the key control factors of drying and storage operations for maintaining and enhancing the quality of food. Real-time monitoring and management of these parameters improve the level of post-harvest processing and reduce losses. An effort has been made to develop a data logger for real-time monitoring of the drying and storage environment. It consists of different modules such as precision integrated temperature and relative humidity sensor DHT22, LCD, SD Card, motor control driver, and RTC 3231 for real-time monitoring and data recording of temperature and humidity. An open-source-based software program was developed to integrate all modules in one platform to operate sequentially. Developed data logger tested in a 0.5-tonne grain storage structure and 100 kg capacity solar-powered air-inflated dryer. The temperature of drying air ranged between 29.8 and 38.2°C compared to ambient air temperature ranging from 25.7 and 34°C. Moisture reduction from 22% to 14% (w.b.) was completed in 7.5-9 hours in the developed dryer compared to 11-12.8 hours in sun drying. Variation of temperature and humidity inside double-wall insulated silo is less as compared to the single wall and triple-layer plastic storage structure. The salient features of this developed system are costefficient, portable, robust, and fast use and perform satisfactorily under different conditions.