Abstract: The main aim of this project is to design a system which is used for security of anything like home, vehicle and banking by opening and closing the door. In our research we presented a part of smart home technology which is using Bluetooth in a mobile device, so it will more easy and efficient to use. It also based on Android which is free open source software. In this paper, a system called door locking system using Bluetooth-based Android Smartphone is proposed and prototyped. First the hardware design and software development are described, then the design of a Bluetooth-based Smartphone application for lock/unlock the door are presented. The hardware design for door-lock system is the combination of android smart phone as the task master, Bluetooth module as command agent, 89C52 microcontroller as controller center / data processing center. All of the tests indicate that all goes according to the initial design of this research.

Keywords: Android, GSM, Bluetooth, Smart Phone, Stepper Motor, LCD Display.