Implementasi Sistem Bel Rumah Otomatis berbasis Sensor Ultrasonik

In this research, ultrasonic module is used to develop a simple automatic doorbell system. The system was implemented to help some visitors who are difficultto press a switch of conventional doorbell, such as a child and a disabled people. The aim of this study is to evaluate an optimal vertical and horizontal distance of an object in front of the door where can activate the doorbell system automatically. There are three main modules to implement the system i.e. ultrasonic sensor module; microcontroller based processing unit module; and buzzer module. The sensor module, which installed in the upper side of a door frame with approximately 15 to 20 degrees angle from the door, detects the distances of visitor. The buzzer module will active for five seconds when the visitor in the detection range of the sensor. The results showed that the buzzer module will be active when the sensor detected an object with 101 cm of minimum height (vertically) and 45.33 cm of average distance from the door (horizontally).