Design and Development of an Automated Coin Dispensing Machine Using Arduino

Abstract

The design, development, and implementation of an automated coin dispensing machine based on Arduino are presented in this paper. The system accepts a currency note (simulated through user input) and enables the user to choose the desired coin denomination (i.e., INR 1, 2, or 5) through push buttons. Data for user selection is read using a 16x2 LCD with built-in I2C converter, while servo motors dispense a coin according with the user choice. This prototype is designed for a low cost, small footprint, easy-to-use solution that is well-suited for small businesses, vending operations, and public facilities. In this project, we are using Arduino Uno, Servo motors, Push Buttons, and 16x2 LCD. Its modelling, simulation, and testing were all accomplished within TinkerCad, yielding results that argue for the viability of its physical counterpart. This project demonstrates how microcontroller-based automation can be used to address common currency transaction challenges in public-facing environments. By simplifying the coin distribution process, the machine reduces human effort, minimizes transaction time, and improves user experience. The hardware design is built around affordability and replicability. The Arduino Uno is chosen for its ease of use and programming flexibility. Servo motors offer precise angular control for simulating coin dispensing, while push buttons allow simple and intuitive denomination selection by the user. The 16x2 LCD serves as the user interface for instructions and real-time feedback. The key innovation lies in the system's modularity and adaptability. Although the current implementation is limited to simulated input and basic dispensing logic, it lays a foundation for integrating more advanced features like real note detection using sensors, dynamic change calculation, secure enclosures, and network connectivity for transaction logging. The use of TinkerCad for simulation not only made the project cost-effective but also helped in identifying potential design flaws before physical prototyping. Each module was tested independently and then integrated into the final simulation to validate the overall logic flow and hardware interaction. The project was not only a technical success but also earned recognition by securing the 1st position in an intercollege competition. This emphasizes the practical utility and innovation demonstrated by the solution. Looking forward, the concept can be expanded into a full-fledged system for small-scale retail or service centers.