Development of plum ripeness sorting system using colour sensors

Sorting is an important post-harvest process that extends the shelf life and enhances their market value. At present, plum sorting plums in orchards is usually done manually which is inefficient, time consuming when dealing with large quantities. Moreover, manual sorting incurs high labour costs and is subject to variabilities due to differing individual judgement standards. To address these challenges, an automated sorting machine capable of rapidly detecting and categorizing plums based on colour is proposed. This machine aims to improve productivity by efficiently grouping fruits according to their ripeness. The system utilizes the TCS3200 colour sensor to classify plums into four categories: unripe, semi-ripe, fully ripe, and rotten. The sorting process is driven by a servo motor and controlled by STM32 and ESP32 microcontrollers.