Design and Simulation of Smart Touchless Dispenser Using AT89C51 Microcontroller

Abstract

In the wake of increasing hygiene awareness, automation in liquid dispensing systems has gained significant relevance. This paper presents a low-cost, efficient, and compact solution for a smart touchless dispenser using the AT89C51 microcontroller. The system is designed to activate and deactivate a DC motor based on simple button-based user input, mimicking gesture control without the need for expensive sensors or complex interfacing modules. The use of push buttons as gesture proxies simplifies the hardware design and makes the system accessible for educational and prototype purposes. The motor-driven mechanism facilitates the dispensing of liquid such as soap or sanitizer in a contactless manner. The primary objective is to demonstrate how basic embedded system components can be utilized to implement practical automation with minimal resources. The proposed system ensures easy integration, low power consumption, and real-time response, making it ideal for public hygiene systems and small-scale embedded projects.

Introduction

The paper presents a low-cost, simplified smart touchless dispenser prototype using the AT89C51 microcontroller (8051 family). Instead of expensive infrared or ultrasonic sensors, it uses two tactile push buttons to simulate start and stop gestures, directly controlling a DC motor without additional driver circuitry. This minimalistic design offers an economical and educational platform for beginners in embedded systems.

The system architecture includes input switches connected to the microcontroller's Port 1, the microcontroller unit itself, a DC motor on Port 2, and a regulated 5V power supply. The device was simulated successfully using Proteus Design Suite and programmed in Embedded C via Keil µVision, showing quick and reliable motor control with no delay or debounce issues in simulation.

Key benefits of the design include simplicity, reliability, user-friendly control, and minimal hardware requirements. The paper also discusses practical upgrades such as replacing push buttons with IR proximity sensors for true touchless operation, swapping the DC motor for a water pump or servo motor for liquid dispensing, and adding transistor switches and voltage regulators for safe, stable hardware operation.

The project validates the AT89C51’s capabilities for automating liquid dispensing tasks efficiently and serves as a strong educational example and prototype for future development of fully automated, hygienic dispensers.

Conclusion

Global emphasis on hygiene and automation has accelerated demand for contact free systems—especially in health sensitive settings where traditional dispensers require touch and risk germ transmission. Although modern touchless solutions often rely on costly infrared or ultrasonic sensors and motor driver ICs, these components are impractical for low budget applications. This paper presents a simplified smart touchless dispenser prototype based on the AT89C51 microcontroller (8051 family). Instead of complex sensors, it uses two tactile push buttons to mimic user gestures (start and stop) and drives a DC motor directly, without external driver circuitry. The minimalist approach yields an economical, educational platform for students and beginners in embedded systems.

References

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Copyright

Copyright © 2025 Kshitij Pathak, Nihal Nipane. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.