HOME SECURITY SENSOR SYSTEM USING ATMEL AVR MICROCONTROLLER LIM BOON HOI



Similar documents
Understanding Alarm Systems

Intruder Alarm Advice for Domestic Properties

Contents TABLE OF. List of Illustrations... IX. Preface... XV. Chapter 1: How the Burglar Breaks into Your Home... 1

ACTIVE INFRARED MOTION DETECTOR FOR HOUSE SECURITY SYSTEM MIOR MOHAMMAD HAFIIZH BIN ABD. RANI UNIVERSITI MALAYSIA PAHANG

A Review of Security System for Smart Home Applications

BURGLAR ALARM SYSTEMS BURGLAR ALARM SYSTEMS BURGLAR ALARM SYSTEM EURO ALARM WIRELESS BURGLAR ALARM SYSTEM OASIS

Intelligent Home Automation and Security System

868 Mhz. Wirefree DIY. Friendly. Easy Fit Range of Alarms

DC-8706K Auto Dial Alarm System

Invisible EYE for Security System

HOME AUTOMATED LIGHTING CONTROL USING ATMEL AVR MICROCONTROLLER LEONG CHING HOONG

about your house How to Lock Out Crime: Home Security Alarms

HOME ALARM MONITORING NETWORK GOH SWEE TIAN

AN INTERNET OF THINGS (IOT) BASED SECURITY ALERT SYSTEM USING RASPBERRY PI

INTRUSION ALARM SYSTEM

TX GSM SMS Auto-dial Alarm System. Installation and User Manual

MICROCONTROLLER BASED SMART HOME WITH SECURITY USING GSM TECHNOLOGY

LYNX Touch Small Business Solutions DYNAMIC, FULL COLOR SELF-CONTAINED BUSINESS CONTROL SYSTEM. Your Connected Business

ABB Stotz-Kontakt GmbH ABB safe&smart Project planning of security systems

Home Alarm System. Product Description

VR8. User Guide Intruder Alarm System

BE SAFE AND SECURE. Landmark Security... giving you peace of mind.

Wireless AUTODIAL GSM SMS Home Alarm Security System 900/ 1800/ 1900Mhz(CK-GSM-9003)

GC2 Panel User Guide

GSM ALARM SYSTEM USER MANUAL

Overview. Components of an alarm system Technology behind the equipment Communication Platforms Industry Terminology False Alarm Tips DSC products

Additional Instruction

HELP DESK SYSTEM IZZAT HAFIFI BIN AHMAD ARIZA

Performance Objective Identification Worksheet

Keys to understanding your alarm system

Quick Installation Guide LCD GSM ALARM SYSTEM LH

User Manual CN2HK LIMITED. Complete Wireless Home Alarm Security System (CK-8806) ENG. Please read this manual before operating this product.

What is an intruder alarm?

Enjoy it. SA 2700 Wireless Security Alarm

How To Control A Car Alarm On A Car With A Remote Control System

Solution Ultima ICP-CC488 Home security you can rely on

ISSN: ISO 9001:2008 Certified International Journal of Engineering Science and Innovative Technology (IJESIT) Volume 2, Issue 3, May 2013

Guardian Home Security System

P/N Rev D

DEVELOPMENT OF DATA ACQUISITION SOFTWARE FOR CENTRALIZED RADIATION MONITORING SYSTEM

PROFESSIONAL HOME ALARM SYSTEM. Important! Please read these instructions carefully.

Nice. Simplicity has come home! alarm shop. Innovation and simplicity in the integrated management of home alarm and automation systems.

Home Security System Using Gsm Modem

USER INSTRUCTIONS CONTENTS

JOB AGENT MANAGEMENT SYSTEM LU CHUN LING. A thesis submitted in partial fulfillment of. the requirements for the award of the degree of

Smart Home Security System Based on Microcontroller Using Internet and Android Smartphone

Destiny Destiny Owners Manual

securıty HOME home protection 101

S100. GSM House Alarm System.

Wireless peripherals

Crime Central Station Burglary Alarm Systems

Hills wireless security alarm DIY range

DEVELOP AND DESIGN SHEMATIC DIAGRAM AND MECHANISM ON ONE SEATER DRAG BUGGY MUHAMMAD IBRAHIM B MD NUJID

PASSIVE INFRARED INTRUSION DETECTOR PASSIVE INFRAROOD DETECTOR DETECTEUR D INTRUSION PASSIF INFRAROUGE

Solution Ultima ICP-CC488 Home security you can rely on

in partnership with Virgin Media

SERIES ͲΝΒΣΞ ΒΟΘΖ Swann 2013

TELE-SAFE HOME SECURITY SYSTEM

INSTRUCTION MANUAL PC5OO WITH PC5OORK KEYPAD

DESIGN AND IMPLEMENTATION OF LOW COST HOME SECURITY SYSTEM USING PIC MICROCONTROLLER ANDGSM NETWORK

PC Tab INSTALLATION MANUAL SECURE-IT, INC. EAST LONGMEADOW, MA / (fax)

LW A. Wireless Auto Dial Alarm System. Sentry Plus User Manual By Global Gadgets

GSM Alarm System User Manual

tattletale User Guide Consumer unit version P a g e

Users Manual of GSM Home Alarm System with Photo-taken

S I E R R A PRODUCT INFORMATION GUIDE FOR HOME SECURITY. SIERRA Page 1

To Real Home Security

Automated Security System using ZigBee

FIRST ALERT INSTRUCTION MANUAL FOR FA 270 KEYPADS SECURITY SYSTEM

Security Alarm Monitoring Protocol

GSM Home Alarm System User Manual.

The Constituents of a Security System

Car Rental Management System (CRMS) Lee Chen Yong

GLOSSARY of SECURITY TERMS

GUIDE TO HOME SECURITY

THE FINGERPRINT IDENTIFICATION OF ATTENDANCE ANALYSIS & MANAGEMENT. LEE GUAN HENG (Software Engineering)

securıty HOME home protection 101

Wireless Security System

Residential & Commercial Alarm Systems by Gross Security, LLC

Rogers Smart Home Monitoring QUICK START GUIDE ROG_6093_QST_GDE_EN.indd 1 9/22/12 8:29 AM

Wireless Alarm system s manual

Elite 8D/Lite Version 8 Zone Controller. Arrowhead Alarm Products Ltd. Operating Guide. Proudly Designed and Manufactured in New Zealand

WIRELESS HOME ALARM SYSTEM (WHA1)

LCD -based Intelligent Burglar Alarm System. User Guide. Ver 2.0

Using your LED Plus keypad

Using Your. Security System With Icon Keypad S5020, S5021, S5022

Thank you for the opportunity and privilege to introduce the services offered by Silver Space Electro Mechanical Works L.L.C.

Home Security Alarm System

D24 ALARM CONTROL PANEL USER S MANUAL REVISION 1.1 A$12.00 INC GST

Alarm Systems. The purpose of an intruder alarm system is: Commonly utilised detection devices include:

Melaleuca Home Security

Home & Office Security, Personal Alarms & Safety Products

Alarm User Awareness Class. National Burglar & Fire Alarm Association

Your Ademco. Fir&Burglar Alarm System. LogiCenter INTRODUCTION: 1. _- ALARM DEVICE MANUFACTURING CO.

TABLE OF CONTENTS. SUPERVISOR S DECLARATION ii STUDENT S DECLARATION iii DEDICATION ACKNOWLEDGEMENTS v ABSTRACT LIST OF TABLES

Videofied Video Verification A Guide for Central Monitoring Stations

CLIENT SERVER APPLICATION FOR SERVER FARM PERFORMANCE MONITORING ABDIRASHID HASSAN ABDI

The IoT s application to protect your family

SECURITY SYSTEM NOTES. Security System Configuration

Home Security System

Transcription:

HOME SECURITY SENSOR SYSTEM USING ATMEL AVR MICROCONTROLLER LIM BOON HOI This project is submitted in partial fulfillment of the requirements for the degree of Bachelor of Computer Science with Honours (Network Computing) Faculty of Computer Science and Information Technology UNIVERSITI MALAYSIA SARAWAK 2006

ACKNOWLEDGEMENT First and foremost, I would like to send my utmost gratitude to the Faculty of Computer Science and Information Technology, University Malaysia Sarawak for giving me an opportunity to do this final year project. I would also like to thank and acknowledge the contribution of my supervisor, Dr. Tan Chong Eng for guiding me through in this final year project. He has given full support and motivation for my final year project. And to Dr. Wang Yin Chai for being the coordinator of this final year project where he has also given guidance to us. I would like to thank my family for their encouragement and support. Lastly but not least, to everyone who has helped me in the final year project and bringing the best memories throughout the processes of completing project. ii

ABSTRACT The AVR Flash Microcontroller based Home Security Sensor System is an automated home alarm system with built-in centralized security monitoring system prototyped using the Atmel STK500 starter kit. The system is able to monitor the house by displaying the information of the current condition of the house and trigger the alarm when the house is being broken in. The development of this home security sensor system involves both hardware and software components. The hardware interface is used to connect all the sensors in the model of the house together with a display panel. The hardware circuit design is built on the AT90S8515 microcontroller. The software program developed is used to control all the functions of the system and it is developed using the AVR studio. The AVR studio is a specific tool for Atmel based assembly program development and debugging. The Home Security Sensor System can be further extended to become more comprehensive in the future. iii

ABSTRAK AVR Flash Microcontroller based Home Security Sensor System merupakan satu sistem alarm rumah automatik yang mempunyai pengawal keselamatan berpusat dengan menggunakan Atmel STK500 starter kit sebagai landasan asal. Sistem ini boleh mengawal rumah dengan memaparkan keadaan semasa dalam rumah dan membunyikan loceng apabila rumah dicerobohi. Pembangunan sistem rumah keselamatan ini melibatkan pembinaan fizikal/perkakasan dan perisian. Antaramuka fizikal digunakan untuk menyambungkan sensors ke rumah dengan papan pemapar. Fizikal litar direka di atas AT90S8515 microcontroller. Bagi pembangunan pengaturcaraan, perisian pula digunakan untuk mangawal semua fungsi dalam sistem ini. Pembangunan perisian ini menggunakan AVR studio. AVR Studio ialah sebuah perkakasan bagi Atmel yang berdasarkan pengaturcaraan assembly. The Home Security Sensor System berpontensi untuk dibangunkan dengan lebih canggih lagi. iv

TABLE OF CONTENTS ACKNOWLEDGEMENT ABSTRACT ABSTRAK TABLE OF CONTENTS LIST OF FIGURES LIST OF TABLES ii iii iv v x xii CHAPTER 1: AN OVERVIEW 1.0 Introduction 1 1.1 Problem Statement 2 1.2 Objective 3 1.3 Methodology 3 1.3.1 Phase 1: Planning 3 1.3.2 Phase 2: System Analysis 4 1.3.3 Phase 3: System Design 4 1.3.4 Phase 4: System Implementation and Integration 5 1.3.4.1 Stage 1: Hardware Implementation 5 1.3.4.2 Stage 2: Software Implementation 5 1.3.4.3 Stage 3: System Integration 5 v

1.3.5 Phase 5: System Testing and Evaluation 6 1.4 Scope of Project 6 1.5 Significance of Project 6 1.6 Expected Outcome 7 1.7 Summary 7 CHAPTER 2: LITERATURE REVIEW 2.0 Introduction 8 2.1 Background Study 9 2.1.1 The Operation of Security Alarm 9 2.1.2 The Operation of Magnetic Sensor 10 2.1.3 The Operation of Motion Detector 10 2.1.4 The Operation of Vibration Detector 12 2.1.5 How the Burglar Breaks into a House 12 2.2 Reviews on Existing Security System and Sensors 13 2.2.1 NAPCO Gemini P816 Security Panel 13 2.2.2 Home Alarm system 14 2.2.3 48-Zone-Customizable Caddx Security System 16 2.2.4 DDT-15 New Generation Professional Diffused Spectrum Analysis 17 Detector with PIR & MW Dual-tech Novel 2.2.5 Comparing the Features of the Existing Systems 19 vi

2.3 Microcontroller 20 2.3.1 Atmel AVR Microcontroller 20 2.3.2 Comparison of Microcontroller 22 2.4 Summary 23 CHAPTER 3: REQUIREMENT ANALYSIS AND SYSTEM DESIGN 3.0 Introduction 24 3.1 Requirement Analysis 24 3.1.1 Physical Hardware Requirement 24 3.1.1.1 Atmel AVR STK500 Flash Microcontroller Starter Kit 25 3.1.1.1.1 STK500 Switches and LED 27 3.1.1.1.2 STK500 Port connection 29 3.1.1.1.3 STK500 Jumper 30 3.1.1.1.4 STK500 Target Socket Section 30 3.1.1.1.5 AT90S8515 Microcontroller 32 3.1.1.2 Sensors 37 3.1.1.2.1 Magnetic Sensor 37 3.1.1.2.2 Vibration Sensor 37 3.1.1.2.3 Passive Infrared Motion Sensor 38 3.1.1.3 Display Panel and Siren 39 3.1.1.3.1 Control Panel 39 vii

3.1.1.3.2 Keypad 39 3.1.1.3.3 Siren 39 3.1.2 Communication Port Requirement Analysis 40 3.1.3 Software Requirement Analysis 40 3.2 System Design 41 3.2.1 Hardware Interface Design 41 3.2.1.1 Security Sensor System Circuit Design Layout 42 3.2.2 Security Sensor System Flow Chart 46 3.3 Summary 47 CHAPTER 4: IMPLEMENTATION AND TESTING 4.0 Introduction 48 4.1 Hardware Interface Implementation 48 4.1.1 Home Sensors Implementation 48 4.1.2 Display Panel Implementation 50 4.2 Software Implementation 52 4.3 Integration of the System 54 4.4 System Testing and Evaluation 55 4.5 Summary 55 viii

CHAPTER 5: CONCLUSIONS AND FUTURE WORK 5.0 Introduction 56 5.1 Conclusions 56 5.2 Future Work 57 REFERENCES 58 ix

LIST OF FIGURES Page Number Figure 2.1 The Magnetic sensor 10 Figure 2.2 Motion detector- Radar-based motion detectors 11 Figure 2.3 Vibration Sensor 12 Figure 2.4 How burglar breaks into the house 13 Figure 2.5 NAPCO Gemini P816 Security Panel 14 Figure 2.6 Home Alarm System 15 Figure 2.7 48-Zone-Customizable Caddx Security Systems 17 Figure 2.8 DDT-15 New Generation Professional Diffused Spectrum Analysis Detector with PIR & MW Dual-tech Novel 18 Figure 2.9 Atmel AVR STK500 Programmers and Starter Kit 21 Figure 3.1 Physical Hardware Components That Required In This Security Sensor System 25 Figure 3.2 The connections to the STK500 25 Figure 3.3 The STK500 Starter Kit Schematic 26 Figure 3.4 The special Function and Status Indication LEDs 27 Figure 3.5 The STK500 Components 28 Figure 3.6 The LED and Switches Schematic 28 Figure 3.7 The General Pinout of I/O Port Headers 29 Figure 3.8 The I/O Ports Schematic 29 Figure 3.9 The default Jumpers Setting 30 Figure 3.10 The AT90S8515 AVR RISC Architecture 33 Figure 3.11 The AT90S8515 Data Block diagram 34 Figure 3.12 Memory Map 35 Figure 3.13 Pin Configurations 35 x

Figure 3.14 Print screen of AVR studio 41 Figure 3.15 Logical Structure of the Security Sensor System 42 Figure 3.16 Figure 3.17 Display panel with LED connected to the Atmel STK500 s port B. Home Security Sensor System design layout connected to the Atmel STK500 s port D. 43 44 Figure 3.18 Home Security Sensor System circuit design layout 45 Figure 3.19 Overall circuit layout of the home security sensor system 45 Figure 3.20 The Security Sensor System Flow Chart 46 Figure 4.1 A house model with switches (sensors) 49 Figure 4.2 The connection pins of each wire to 10-pin cable at port D 49 Figure 4.3 The 8-N-1 format 49 Figure 4.4 The connection of the house model to the STK500 starter kit through Port D 50 Figure 4.5 Display panel with LED 50 Figure 4.6 Figure 4.7 The connection pins of each wire to the 10-pin cable at port B The connection of the display panel to the STK500 starter kit through Port B 51 51 Figure 4.8 Hardware connection of the system 54 xi

LIST OF TABLES Page Number Table 2.1 Features of NAPCO Gemini P816 Security Panel 14 Table 2.2 Features and benefits of Home Alarm System 15 Table 2.3 Table 2.4 Table 2.5 features of 48-Zone-Customizable Caddx Security System Features of DDT-15 New Generation Professional Diffused Spectrum Analysis Detector with PIR & MW Dual-tech Novel Monitored alarm systems and alarm monitoring from national alarm companies compared 17 18 19 Table 2.6 Features of Atmel AVR STK500 22 Table 2.7 Microcontroller Comparisons 23 Table 3.1 The description of jumpers 30 Table 3.2 AVR Socket 31 Table 3.3 The detail information about AT90S8515 features 32 Table 3.4 Pin Description Summary 36 Table 4.1 The Source code of the home security sensor system prototype 53 xii

CHAPTER 1 AN OVERVIEW 1.0 Introduction In this fast and rapid growth of information technology era, most of the people nowadays can live in comfort zone. People can get whatever they want easily and go wherever they want. The criminal rate is increasing day by day. Robbery, burglary, and rape are happening everywhere. People are afraid of walking alone, living in frighten, no peace in their heart when they go out or traveling, and hence people reduce their out door activities. From a survey that done by the National Crime Prevent Council (NCPC), most of the people feel safe when they are in the house, in workplace and in the community [NCPC, 2001]. Most of the people nowadays are preferred to stay at home. Since Internet is widely used and everywhere, by having Internet at home, people think that they do no need to go out to socialize with other people. Crime rates continue to increase nationwide. Mark Jarrett from British Gas Home Security said that the crime statistic shows that 18.2% of the households with no security system were burgled compared to there was only 0.7% out of 2% household with high level of security system being entered [Centrica, 2004]. Some people may believe that locking all the doors and windows, using hardwood or metal for outside doors and door frame and so on 1

will make the house a safer place. In reality, these are still not safe enough! Burglars still can break into the house. The National Crime Prevent Council (NCPC) suggests the homeowner to install an alarm system for summoning emergency help [NCPC, 2001]. When the house is broken in, the alarm system will be triggered and alert the homeowner or neighbours. Therefore, homeowner or neighbours can take necessary reactions. Even though, a security system cannot give 100% guarantee that the house is safe, but at least it managed to reduce the crime rate. 1.1 Problem statement Due to the increase in crime rate, most of the houses today are lacking of a security system to protect the home. A good lock for doors and windows is just not enough. The National Crime Prevent Council (NCPC) suggests the homeowner to install the alarm system [NCPC, 2002]. A security systems that only trigger the alarm is just not good enough, it only can get attention from the homeowner and neighbours. Sometimes it may scare the burglar, but most of the time they will not afraid of the alarm. Most of the homeowners would like to know the current state of their house even before the alarm system is triggered. The lack of features such as monitoring in an automated alarm system, will never give a total peace of mind to the home owners. 2

1.2 Objective The purpose of this project is to develop a security sensor system for smart home. The project aims to: i. Create an automated home alarm system with monitoring feature built-in based on the Atmel AVR STK500 starter kit. ii. Create an alarm system that is able to monitor the house by displaying or providing the information of the current condition of the house (centralized security monitoring system). iii. Create an alarm system that is able to trigger the alarm and send a signal to homeowner when the security system has been triggered or detecting moving objects like human in the house. 1.3 Methodology In order to complete this project, several phases are needed. This project starts with planning the system. Then, analysis and design of the system. Finally, it is implemented and tested. 1.3.1 Phase 1: Planning In this phase, feasibility study will be conducted. It involves identifying the project goals, objectives, problems, project contributions, and system requirements. The methods to be adopted by the security sensor system in the planning phase are: 3

Literature reviews on the existing security systems and study their background to understand more about the security sensor features and functionality. Exploration on how the Atmel AVR STK500 microcontroller works and understands the AVR studio by testing some of the example assembly programs. 1.3.2 Phase 2: System Analysis In this system analysis phase, analyze and specify system requirements, finalize systems objectives, and define system functionality will be done. The information gather in phase 1 during the feasibility studies will be used to further define the system goals and functions. The methods to be adopted by the security sensor system for this phase 2 are: Analyzing the existing security systems and comparison among the systems which similar to the proposed security sensor system. Performing search for appropriate hardware required by the system. Analyzing of hardware and software requirements for the system such as sensor circuits and assembly language to use. 1.3.3 Phase 3: System Design At this phase, a detailed implementation plan will be developed, revise cost estimation, and produces the Systems Design Specifications. The methods to be adopted by the security sensor system for this design phase are: 4

Design and propose a standalone security system specifically for home use. Sensor circuit design Design the logical flow of the system. 1.3.4 Phase 4: System Implementation and Integration In this phase, the security sensor system will be divided into three stages. Therefore, developer can be more focus on a small module and become more effective compare to doing the whole system at once. Besides that, it also helps to refine the vital components of the system that needs more time to develop. 1.3.4.1 Stage 1: Hardware Implementation Implementing, setup and configuring all the sensors and come out with a functional prototype. This prototype will be developed based on the sensor circuits design that was defined in the previous phase. 1.3.4.2 Stage 2: Software Implementation Program will be developed to implement all the applications that have been proposed for the security system by using assembly language. 1.3.4.3 Stage 3: System Integration Integrating the hardware and software systems to produce the final system. Solve the system errors or hardware errors once integrate. 5

1.3.5 Phase 5: System Testing and Evaluation After the system is completely built functionality and usability testing will be carried out. Feedbacks gather from the tests will be used to further improve the final system. Documenting process will also be carried out in line with the testing and evaluation. 1.4 Scope of Project This prototype system is designed only for home use. The security sensors will be implemented by homeowner in their house. This system only includes the basic security applications implemented using the Atmel AVR STK500 microcontroller. This system not only can trigger the alarm when the security is breach, but also capable of performing centralized security monitoring under normal home conditions. 1.5 Significance of Project The significance of this project is to provide a solution to the problem faced by the homeowner which is the security of their house. By implementing this security system in the house, users are able to check their house condition from time to time. They can monitor their home from a centralized location where they will know exactly which part of the house has been broken in. This will give them additional information to plan for the actions required to counter the break-in. 6

1.6 Expected Outcome When this working prototype of security system is fully developed, it will be able to trigger the alarm and alert the user at the centralized control panel when the sensor is triggered. This system can also alert the user when the motion sensor detects any moving object. Users can know their house conditions through the centralized control panel. 1.7 Summary Chapter 1 gives an idea about the importance of having a security system at home. The problem statements, objectives, methodology, and expected outcome are discussed as well in this chapter. 7

CHAPTER 2 LITERATURE REVIEW 2.0 Introduction Statistic showed that burglars attack homes without electronic security three times more often than homes with a system [TCPALM Network]. Therefore, knowing how to choose a good or suitable security system for home is important. A good system covers the entire perimeter of your home and at least one internal trap [TCPALM Network]. The size and layout of the home must be taken into consideration when designing the overall system. The alarm system should be loud and clearly heard [Vivian Capel, 1997] but also easy to use. The system chosen must also reliable and less false alarms happen. In the Metropolitan Police area no less than 98% of the call-outs are for false alarms. So, it is a waste of time and resources [Vivian Capel, 1997]. Basic elements of a standard system includes: a keypad, control panel, a siren, an inside motion detector and door contacts [TCPALM Network]. And it must be linked to a central monitoring station. Additional protection should be added to meet the individual needs of the property being protected. 8

2.1 Background Study Before go into the detail of the current technologies, an overview of the security alarm and sensors will be discussed in this chapter to further the understanding of the techniques used in the similar system. 2.1.1 The Operation of Security Alarm Most of the security alarm systems or burglar alarms are simple electric circuit built into an entry way. In any circuit, electricity only flow when giving the path between two points of opposite charge. In order to turn on the electric current, it needs to close the circuit by a using switch. In order to turn off the electricity, it needs to open the circuit. In the security alarm system, a switch detects the act of intrusion. For example, open or close the door and window. In a closed-circuit system, the electric circuit is closed when the door or window is closed. This means that as long as the door is closed, electricity can flow from one end of the circuit to the other. But if somebody opens the door, the circuit is opened, and electricity cannot flow. This triggers the alarm. While in an open-circuit system, opening the door closes the circuit, and electricity begins to flow. In this system, the alarm is triggered when the circuit is completed. The modern alarm system insert a control box inside their system in order to prevent burglar closes the door after triggering the alarm and turn off the alarm. This control box has its own power supply even though it hooked on the alarm circuit. It monitors the circuits and sounds the alarm when they are closed or opened. When the alarm is triggered, the control 9

box will not cut off until someone has enters a correct security code at the connected keypad. [HowStuffWorks] 2.1.2 The Operation of Magnetic Sensor Magnetic sensor works closely related to security alarm system. When the door or window is closed, the magnet pulls the metal switch closed so the circuit is complete. When you move the magnet by opening the door or window, the spring snaps the switch back into the open position. This cuts off the current and closes the relay, then sounding the alarm. Figure 2.1 shows examples of magnetic sensor. [HowStuffWorks] Figure 2.1 The Magnetic sensor 2.1.3 The Operation of Motion Detector There are several different sorts of detectors. Radar-based motion detector sends out bursts of microwave radio energy (or ultrasonic sound waves), and then waits for the reflected energy to bounce back. If there is nobody in front of the door, the radio energy will bounce back in the same pattern. But if somebody enters the area, the reflection pattern is disturbed. 10

When this happens, the sensor sends a signal and the door opens. In a security system, the sensor sends an alarm signal when the reflection pattern in a room is disturbed as shown in Figure 2.2. [HowStuffWorks] The motion detector emits radio energy into a room and monitors the reflection pattern. If somebody disturbs the reflection pattern, the motion detector sends an alarm signal to the control box. Figure 2.2 Motion detector- Radar-based motion detectors Another type of motion detector is photo-sensor motion detector. There are two types of components: focused light (laser beam) and light sensor. Normally, the light sensor will be used for home. When somebody walks between the light source and the sensor, the path of the beam is blocked briefly. The sensor registers a drop in light levels and sends a signal to the control box. [HowStuffWorks] Passive infrared (PIR) motion detectors are more advanced than others. These sensors sense the infrared energy emitted by an intruder's body heat. When an intruder walks into the field of view of the detector, the sensor detects a sharp increase in infrared energy. PIR detectors are designed to trigger the alarm only when infrared energy levels change very rapidly. [HowStuffWorks] 11

2.1.4 The Operation of Vibration Detector These devices consist of a leaf spring suspended at its top and having a weight fixed to its free end. At the free end is a contact that mates with another which is fixed to the case. The pressure between the contacts, which are normally closed, is adjusted by a set-screw which thereby sets the sensitivity of the device. Any vibration or movement will cause the contacts to part, this will initiate an alarm. Figure 2.3 shows the components of a vibration sensor [Vivian Capel, 1997] Figure 2.3 Vibration Sensor 2.1.5 How the Burglar Breaks into a House According to the National Crime Prevention Center, there are several ways for a burglar to break into the house for example through a door, window, garage, basement and so on. According to the statistic done by the National Crime Prevention Center, 34% of the burglary is through the front door; followed by 23% through the first floor windows and 22% is broken in through the back door as shown in Figure 2.4. From the survey, it can be 12