Cost effective wireless attendence and access control system

In this paper, design of a cost effective RF based attendance and access control system for office use is presented. The design utilizes a low cost and readily available wireless door bell for wireless transmission of user information. The user module consists of an AT89C52 microcontroller which transmits different codes using transmitter section of door bell corresponding to various push buttons for attendance and access control purposes. The receiver section of door bell is also interfaced to AT89C52 microcontroller which recognizes the code and passes it to central computer through serial port interface. Computer software developed using Visual Basic keeps record of check-in and check-out time of employees and calculates the salary accordingly. In case if the transmitter is lost, the employee is required to inform the central station with the help of a mobile or through emergency device installed at central station for prevention of possible misuse and theft detection.