Multi Security System

Transcription

1 Page 1 TRIBHUVAN UNIVERSITY INSTITUTE OF ENGINEERING Pulchowk Campus A Project Report on Multi Security System Submitted to LOCUS 2014 Team Submitted By Manish Munikar 070-BCT-520 Kritish Pahi 070-BCT-517 Arun Kumar Agrawal 070-BCT-509 Miran Ghimire 070-BCT-521 June, 2014

2 Page 2 TABLE OF CONTENTS Abstract 3 Introduction 4 Objectives 5 Literature Review 5 Methodology 6 Limitations & Future Improvements 7 Conclusion 7

3 Page 3 ABSTRACT Home security is one of the most sensitive and important part of everyone s lives. Everyone wants to keep their house and their valuable properties as safe as possible. Nobody wants their precious possessions to be easily able to be stolen or destroyed by fire. But we can t keep our important stuffs safe just with our human consciousness and attention because we humans have many other things to worry about. We need an extra helping hand, a technological helping hand. That s why almost all the offices, malls, banks, stores etc are equipped with advanced technological security system to keep the place secure against malicious people. That was for the big stores and offices. But we don t see such security systems in general residential homes. But it s not because the things in homes are less important than those in large offices. Rather it s because residential people don t think investing heavy on such systems is worth it. Implementing those advanced technological security systems in homes is just not sensible because such advanced security systems are most probably not required in homes and they are too expensive. Keeping these things in mind, we decided to develop this Multi Security System, a much less sophisticated security system that is simple, affordable, and yet effective enough to be used at residential homes or small-scale stores.

4 Page 4 INTRODUCTION The Multi Security System is a small collection of simple security techniques that can be used at homes and small-scale stores to provide security against thieves, burglars and fire, and by security, we mean a simple alarm system here. The three independent security modules we ve implemented in our project are: Laser-based Intruder Detection It is a basic security circuit that triggers the warning alarm whenever an intruder crosses the path of a laser light. It is constructed with a laser light pointing towards a LDR (Light Dependent Resistor). A microcontroller is programmed in such a way so as to switch on the alarm whenever the path of the laser light is blocked. It can be used to protect the house from thieves and burglars, especially at night when we are all sleeping and unaware of the house. Temperature Sensing Fire Alarm This is another simple circuit that senses the temperature of the room. It can be used to detect fire and help avoid unwanted damages caused by sudden fire. It uses the very popular LM35 Temperature Sensor to sense the environment temperature. Its output is connected to the micro-controller which is programmed to trigger the alarm when the temperature of the room exceeds 50 C. Touch-based Intruder Detection This is yet another very simple circuit that can be used to detect the intruders who have somehow bypassed the laser-based detection system. In this circuit, two thin metal plates are fixed very close to one another and is kept under the carpet or doormat near the place of valuable possession. Whenever the intruder steps on it, the pressure will make the two plates come in contact and current flows through them to again trigger the alarm.

5 Page 5 OBJECTIVES To develop a simple security system that can be used at small homes. To create a simple and cheap security system that is still effective enough for practical use. To protect houses and small stores and offices from thieves, burglars and sudden fire. LITERATURE REVIEW This is a project full of simple concepts and principles. Everyone with a basic electronic knowledge can understand, use and even make this. However, some of the important hardware/software/concepts used in this project are as follows: Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. It is a technique of getting amplified and highly intense beam of light of a particular wavelength by exploiting the meta-stable property of some materials. But for general purpose, laser diodes are more popular because it is more affordable. Light Dependent Resistor (LDR or Photo-cell) is a special type of resistor whose resistance depends on the intensity of light falling on it. Its resistance decreases rapidly when the intensity of light falling on it increases. Therefore, LDRs are used as light sensors. A Temperature Sensor is a tiny electronic chip that has been programmed to give an output voltage which is proportional to the temperature of the environment. It has three terminals, one for output and the other two for power input. On of the most common temperature sensors in the market is the LM35. It is popular because it is directly calibrated with temperature in Celsius, that is, the output voltage of LM35 is directly proportional to the temperature in Celsius with the factor 10mV per degree Celsius. A micro-controller is an integrated circuit (IC) chip that has various input/output pins and can be programmed in any programming language to do certain digital task. A micro-controller is like a small computer. It has a memory, an internal clock, a timer, I/O pins, Analog to Digital Converter (ADC), Digital to Analog Converter (DAC), etc. The ATMEL ATmega32 AVR is a very popular micro-controller that is big and powerful enough, but not too big.

6 Page 6 The micro-controller is programmed by using a another device called the Programmer which acts as the bridge between computer and the microcontroller and is programmed by the manufacturer to transfer the program from computer into the micro-controller. METHODOLOGY Since this project is our very first taste of electronics engineering, we decided to make a simple security system whose concept is very easy but which is effective enough to be used in houses and small stores. \ For the Laser-based Intruder Detection, we kept a laser light pointing at an LDR. As resistance of LDR decreases when the intensity of incident light increases, the voltage across it also decreases accordingly. So when laser light is incident on it, the voltage across it is low. When the laser light is not incident on it (obstructed by intruder for example) then the voltage across it is high. The voltage across it is given as an analog input to the ATmega32. After converting it into digital value by the ADC, if the voltage is found to be high, the buzzer alarm is triggered. For the fire alarm circuit, we used the LM35 temperature sensor to check the temperature of the environment. The LM35, when powered, gives an output voltage which is directly proportional to the temperature in Celsius, with the proportionality factor 10mV per Celsius. The output of this LM35 is sent to one of the ADC pins of the micro-controller and the temperature is calculated on the basis of the input voltage. When the temperature is found to be greater than 40 Celsius, the buzzer alarm is triggered.

7 Page 7 The touch-sensor intruder detection circuit is even more simple. It just consists of two metal plates (mounted on cardboards) that are placed close to each other and acts as a switch. It is placed on the floor under the carpet or doormat for instance and when anyone steps on it, the two metal sheets are shorted, which is read by the micro-controller and it sends the output to the buzzer alarm. LIMITATIONS & POSSIBLE IMPROVEMENTS Since this is our very first electronics project, we have used very simple techniques and this project has many limitations at the moment which we weren't able to remove due to lack of enough knowledge in electronics engineering. So out project has many rooms for improvements which are briefly listed below: 1. Our project is done on breadboard, which is not a stable way of doing it. Breadboards are just for testing purpose. We could have done it in matrixboard but we faced problems in it. 2. Visible laser lights are easily detectable by using sprays and can be bypassed by using a strong flash light. To eliminate these possibilities we can use infrared lasers and infrared sensors, which cannot be easily detected by human beings. 3. Our project only uses a buzzer as the warning alarm, which is practically is not the most useful method of being alarmed. For better security, we can use SMS alarm, or even digital camera shutter system to take the picture of the intruder. CONCLUSION In this way, we made a simple, affordable yet effective security system that can protect homes and small-scale stores from thieves, burglars and fire-accidents.