Development of an arduino-controlled smart storage rack for component reels using MQTT and RS485 communication protocols

Abstract

This thesis represents the development of an innovative storage rack system designed to manage electronic component reels in the manufacturing environment efficiently. The system integrates multiple custom-designed PCBs equipped with many LEDs and sensors, each assigned to individual storage slots. Each storage slot is equipped with an LED and an infrared (IR) sensor. The sensors detect the presence of reels, while the LEDs provide visual guidance for storing or locating specific reels. To manage multiple sensors efficiently, a multiplexing method is used, allowing each Arduino Pro Mini to control up to 16 sensors with fewer pins. Multiple Arduino Pro Mini microcontrollers are deployed across different rack sections and communicate with a central master controller using the RS485 protocol. The master controller, based on an ESP32, connects to an MQTT broker to send and receive data from a storage management system. Users interact with the system through a web interface. When storing a reel, the user scans it into the online system, which then activates an LED to indicate the appropriate storage slot. When retrieving a reel, the system highlights its location via the corresponding LED. Sensors are used to confirm the presence or absence of reels within the slots ensuring accurate tracking of stored items in real time. The system is modular and scalable. In this thesis, the prototype demonstrates two levels of storage racks, each independently controlled and networked, validating the communication between multiple slave units and a master. Additionally, because of the different sizes of the reel, the design includes removable metal dividers between slots. When storing larger reels, dividers can be removed, and this change is also updated via MQTT to the online system. Power is supplied through a 5V, 30A power supply, ensuring stable operation of all electronic components. Overall, the results confirm that the system achieves reliable performance in both hardware and communication aspects, offering a practical and scalable solution for modern electronic component inventory management