Improving the performance of a banana solar drying cabinet using an automatic temperature control system with IoT-based alerts

Abstract

This research aimed to design and develop a temperature control system for a solar banana drying cabinet using a KidBright32 microcontroller together with a DHT22 temperature sensor. The system also included a notification and data display system via a smartphone application using Internet of Things (IoT) technology. An automatic curtain opening–closing mechanism was designed to control the internal temperature of the drying cabinet within an appropriate range. The system was programmed to close the curtain when the temperature exceeded 60°C and open the curtain when the temperature dropped below 55°C. The experimental results showed that the developed system could effectively maintain the temperature inside the solar banana dryer within the specified range. The system was able to display real-time data and send notifications to a mobile phone. Moreover, the system reduced the time required for opening and closing the shade curtain from an average of 45 seconds using manual operation to only 18 seconds using the automatic system. In addition, compared with traditional sun drying, the system reduced the amount of damaged bananas from an average of 38.18% to 11.82%. The dried bananas produced had more consistent quality in terms of color, aroma, taste, and texture. User satisfaction was at a very high level. The economic analysis showed that the system cost approximately 5,237 baht to build and the investment could be recovered within 4–5 months. Therefore, the developed solar banana dryer control system can improve the efficiency of the banana drying process, reduce waste, improve product quality, and is suitable for application at the household or community level.