| dc.description.abstract | Technological advancements today have led to the emergence of various security
systems that are more efficient and practical. One such innovation is an automatic door
unlocking system that no longer requires a physical key, but instead utilizes a platform
based on the Arduino Uno. This study aims to design and implement a prototype of a door
unlocking system that uses a knock pattern as an authentication method, employing a
piezoelectric sensor and an Arduino Uno microcontroller. The system operates by de-
tecting specific knock patterns that have been previously recorded. When a user knocks on
the door following the saved pattern, the piezoelectric sensor detects the resulting vi-
brations and converts them into signals processed by the Arduino. If the detected pattern
matches the stored one, the system activates a solenoid door lock through a relay module,
allowing the door to open automatically. Test results show that the system can accurately
recognize knock patterns, including the number of knocks, time intervals, and the intensity
of pressure. Additionally, the system features a knock pattern re-recording function and
indicators in the form of a buzzer and LED to provide both visual and auditory feedback
to the user. Furthermore, the system includes an automatic power charging mechanism,
where the piezoelectric sensor converts mechanical pressure into electrical energy, ge-
nerating approximately 17–23 mW of power. By utilizing cost-effective components and a
simple design, this system presents an innovative, practical, and user-friendly alternative
solution for door security accessible even for individuals with disabilities | en_US |
