Automated GSM-based un-locker system

This work presents the design and construction of an SMS-based unlocker system that will allow users to lock or unlock a specific door without using the conventional method. The chief component used in the design of this device is the Atmega328 microcontroller (IC1). The device was designed in modules that include the system power supply unit, microcontroller unit, PIR motion sensor, and GSM SIM900 module. These discrete parts or components on their own are made up of smaller components. The different modules were put together in a particular pattern to form the circuit design. SMS from the authorized user’s mobile phone enables the Arduino controller to automatically unlock the security door when necessary. Basically, it reads the SMS and acts according to the message command, hence allowing the authorized owner to remotely control the door from anywhere using a mobile phone and preventing unauthorized access to the door. The GSM based door unlocking system constructed worked effectively when tested in homes and office doors and is thus recommended in every home for security purposes.