Table of Contents
Introduction:
The need for security and enhanced privacy is increasing as electronic forms of identification replace face-to-face and paper-based ones. The primary purpose of an office access control system (OACS) is to secure access-controlled zones by restricting access to zones to only those persons (or assets) who are allowed access. An access-controlled door is not a single entity but a collection of door hardware that typically includes controlled outputs, such as a door lock, door holder, door sounders, etc., and supervised inputs, such as door contacts, request-to-exit inputs, motion detectors, etc. An access control system has the role to verify and mediate attempts made by users to access resources in a system. An access control system maps activities and resources to legitimate users. The main aim of the present work is to develop an automated low-cost office access control system with the help of a microcontroller(MSP 430). Automation is the use of control systems and information technologies to reduce the need for human work in the production of goods and services. Here a keypad is used to restrict the access of persons and a corresponding password is provided for each individual. So correct password ensures transaction through an electromagnetically locked door whether the wrong password collapses the system and generates an alarm. An LCD is interfaced with the main controller to show different statuses when a user gives his corresponding password.
Block diagram explanation
Power supply unit
This section needs two voltages viz., +12 V & +5 V, as working voltages. Hence specially designed power supply is constructed to get regulated power supplies.
4X4 Keypad:
A keypad is a set of buttons arranged in a block or “pad” which usually bears digits, symbols, and usually a complete set of alphabetical letters. If it mostly contains numbers then it can also be called a numeric keypad. Keypads are found on many alphanumeric keyboards and on other devices such as calculators, push-button telephones, combination locks, and digital door locks, which require mainly numeric input.
RF transmitter
RF transmitters are electronic devices that create continuously varying electric currents, encode sine waves, and broadcast radio waves. RF transmitters use oscillators to create sine waves, the simplest and smoothest form of continuously varying waves, which contain information such as audio and video. Modulators encode these sign wives and antennas broadcast them as radio signals. There are several ways to encode or modulate this information, including amplitude modulation (AM) and frequency modulation (FM). Radio techniques limit localized interference and noise.
RF receiver
RF receivers are electronic devices that separate radio signals from one another and convert specific signals into audio, video, or data formats. RF receivers use an antenna to receive transmitted radio signals and a tuner to separate a specific signal from all of the other signals that the antenna receives. Detectors or demodulators then extract information that was encoded before transmission. There are several ways to decode or modulate this information, including amplitude modulation (AM) and frequency modulation (FM). Radio techniques limit localized interference and noise.
MSP 430 Microcontroller:
MSP low-power microcontrollers (MCUs) from Texas Instruments (TI) are RISC-based, mixed-signal processors that include smart analog and digital peripherals and offer several additional options such as low-power embedded RF and security such as AES encryption. MSP microcontrollers offer the ultimate solution for a wide range of low-power and portable applications.
Buffers
Buffers do not affect the logical state of a digital signal (i.e. a logic 1 input results in a logic 1 output whereas logic 0 input results in a logic 0 output). Buffers are normally used to provide extra current drive at the output but can also be used to regularize the logic present at an interface
Drivers
This section is used to drive the relay where the output is a complement of input that is applied to the drive but the current will be amplified.
Relays
It is an electromagnetic device that is used to drive the load connected across the relay and the o/p of the relay can be connected to the controller or load for further processing.
Buzzer:
A buzzer or beeper is an audio signaling device, which may be mechanical, electromechanical, or piezoelectric. Typical uses of buzzers and beepers include alarm devices, timers, and confirmation of user input such as a mouse click or keystroke.
DC motor:
A DC motor relies on the fact that magnet poles repel and unlike magnetic poles attract each other. A coil of wire with a current running through it generates an electromagnetic field aligned with the center of the coil. By switching the current on or off in a coil its magnetic field can be switched on or off or by switching the direction of the current in the coil the direction of the generated magnetic field can be switched 180°.
Methodology:
In this module, the Transmitter module will be there at the entrance of the office. The receiver will be there in the office center. This module consists of a coded card security system, RF transmitter, and receiver, MSP 430 controller unit, and the output with RF paging. If the office has this module, then every time a person wants to do anything he has to enter the password. After entering the password that signal will be applied to MSP 430 controller, then it analyses the signal and the same information will be transmitted to the center in charge. If the password is correct then the successful ding operation will take place. If the password is wrong then that signal will be transmitted to the receiver via RF Tx and Rx. At the receiver, the buzzer will be activated to indicate the wrong password.
Advantages:
- Easy to use for rural areas also.
- Automated areas.
- Low power consumption.
- Flexible and reliable.
- This application is easy to install and easy to operate.
- More reliable than manual Operation.
- In this project losses are Minimal.
- This project can implement for the Security of supply.
- Automatically controlled & Easy to use.
Disadvantages:
- It increases the cost whereas digital systems reduce the cost of the system.
- High Cost.
Applications:
- This system finds its application in real-time traffic surveillance. It could be used as a valuable tool for real-time travelers.
- This system can be implemented in industries.
- We can implement this project in all vehicles.
- Where security is important there we can implement this project.
