Automatic Door Unlocking System Using PIR Sensor

Automation technologies are increasingly being used in modern security and access control systems. Traditional door locking systems require manual operation and may cause inconvenience in situations where automatic access is preferred. This paper proposes an Automatic Door Unlocking System Using a Passive Infrared (PIR) Sensor to detect human presence and control door unlocking automatically. The PIR sensor detects motion based on infrared radiation emitted by human bodies. When a person approaches the door, the PIR sensor sends a signal to the microcontroller, which processes the signal and activates the door unlocking mechanism using a motor or electronic lock. The proposed system aims to improve convenience, security, and energy efficiency in residential and commercial environments. The system is designed to operate automatically without requiring physical contact, making it suitable for smart homes and automated access control applications. Future improvements may include integration with IoT-based monitoring and smartphone control for enhanced functionality.