This document describes an anti-theft alarm system project using an 8051 microcontroller. It includes an introduction, circuit diagram, block diagram, component descriptions, advantages and applications. The system uses an IR transmitter and receiver, along with an 8051 microcontroller, LCD display, buzzer and power supply. It provides security for vehicles and homes in a simple, easy to understand design requiring continuous power. Future improvements could include sending data remotely, adding additional sensors and a voice alarm module.

1. SYED HASHIM COLLEGE OF SCIENCE & TECHNOLOGY
ANTI-THEFT ALARM SYSTEM
Mini Project
By
MD SHAKIR RAHMA (14565A0401)
Under the Guidance of
ER. ZIAUL HAQUE
Assistant Professor
Department of ECE

2. OUTLINE
Introduction
Circuit diagram
Block diagram
Advantages
Disadvantage
Applications
Conclusion and Future Scope
References

3. INTRODUCTION
Security is the primary concern for everyone. This
project is used to develop the anti theft alarm system
using 8051 micro controller. This project is useful in
all applications where we need security alert. Use of
embedded technology makes this closed loop
feedback control system efficient and reliable. Micro
controller (AT89C51) allows dynamic and faster
control. AT89C51 micro controller is the heart of the
circuit as it controls all the functions.

4. CIRCUIT DIAGRAM

5. Block diagram
8
0
5
1
Power
Supply
IR
receiver
1
IR
receiver
2
16X2 LCD
Buzzer
IR
transmitter
1
IR
transmitter
2

6. Microcontroller
 The Intel 8051 is an 8-bit microcontroller which means
that most available operations are limited to 8 bits.
 Introduced in 1981 by Intel corp.
 It is a 40 pin IC chip
 it has 128 bytes of RAM,
 4Kbytes of ROM,
 2 Timers,
 1 Serial port,
 and four ports on a single chip
 These are designed for embedded applications.

7. • A variable regulated power supply, also called a variable bench power supply.
• This type of regulation is ideal for having a simple variable bench power supply.
• To use these parts we need to build a regulated 5 volt source. Usually we start
with an unregulated power supply ranging from 9 volts to 24 volts DC.

8. IR CIRCUITS:
This circuit has two stages: a transmitter unit and a receiver unit. The
transmitter unit consists of an infrared LED and its associated circuitry.
IR TRANSMITTER:
The IR LED emitting infrared light is put on in the transmitting unit. To
generate IR signal, 555 IC based satiable multivibrator is used. Infrared
LED is driven through transistor BC 548.
IR RECEIVER:
The receiver unit consists of a sensor and its associated circuitry. In
receiver section, the first part is a sensor, which detects IR pulses
transmitted by IR-LED.
(IR) INFRAREDTECHNOLOGY

9.  Liquid crystal displays (LCD‟s) have materials which combine the
properties of both liquids and crystals.
 An LCD consists of two glass panels, with the liquid crystal material
sand witched in between them.
 The LCD’s are lightweight with only a few millimeters thickness.
Since the LCD’s consume less power, they are compatible with low
power electronic circuits, and can be powered for long durations.

10. BUZZER
 A buzzer or beeper is a signaling device,
usually electronic typically used in
automobiles, household appliances such
as a microwave oven, or game shows.
 The word "buzzer" comes from the
rasping noise that buzzers made when
they were electromechanical devices,
operated from stepped-down AC line
voltage at 50 or 60 cycles

11. Prepared kit

12. ADVANTAGES & APPLICATIONS
 Advantages:
This circuit is easy and simple to understand.
This circuit is used wherever security needed.
 Limitations:
Continuous power supply is needed to the circuit for operation.
 Applications:
To provide security for vehicles.
To provide security for house doors.

13. Conclusion and Future Scope
 1. We can send this data to a remote location using
mobile or internet
 2. We can implement other related modules like fire
sensor, wind sensor.
 3. We can add the module of voice alarm system to
indicate theft entry or gas leakage.

14. References
 http://www.electronicsforu.com
 http://www.engineersgarage.com
 http://www.en.wikipedia.org/wiki/filerelay-parts.jp
http://www.projectsof8051.com/home-security-
system/

15. Thank you