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Laser Intruder Alarm System

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[LASER BASED SECURITY ALARM SYSTEM] This Document contains Project Report of Autumn 2012 of Course CT-111. PROJECT REPORT LASER BASED SECURITY ALARM ? An Alarm is a type of security equipment that can be used to safeguard houses and property. ? Now a days Burglar Crimes are continually rising with each passing day. ? Many have lost homes and families through violent burglaries in many countries ? Some of them lost most precious things such as Jewelry, Vehicles, huge investments in banks etc.. ? This led to the development of ALARM SYSTEM Basic circuit Alarm Interface: ? We used LDR to detect Laser Light. LDR pin was Fed to Op-Amp input leg. ? Clock pulse to 4017 was taken from Op-Amp output pin. Light Dependent Resistor (LDR) ? LDRs or Light Dependent Resistors are very useful especially in light/dark sensor circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000 000 ohms, but when they are illuminated with light resistance drops dramatically. ? Which acts as an sensor for our circuit. Op-Amp-741 ? The OP AMP is a ‘Linear Amplifier ? Its main purpose is to amplify (increase) a weak signal ? The OP-AMP has two inputs, INVERTING -2nd pin and NONINVERTING - 3rd pin, and one output at pin 6 1.

An inverting amplifier ? Leg two is the input and the output is always reversed. In an inverting amplifier the voltage enters the 741 chip through leg two and comes out of the 741 chip at leg six. If the polarity is positive going into the chip, it becomes negative by the time it comes out through leg six. The polarity has been ‘inverted’. 2. A non-inverting amplifier ? Leg three is the input and the output is not reversed. In a non-inverting amplifier the voltage enters the 741 chip through leg three and leaves the 741 chip through leg six. This time if it is positive going into the 741 then it is still positive coming out.

Polarity remains the same. How it helps ? ? When the illumination on LDR stops its resistance increases so the leg 2 of Op-Amp gets less voltage. ? Then it acts as non-Inverting amplifier. ? It gives high voltage to transistor which ultimately passes current to buzzer and the buzzer buzzes. 4017-Timer ? The 4017 decade counter has ten outputs which go HIGH in sequence when a source of pulses is connected to the CLOCK input and when suitable logic levels are applied to the RESET and ENABLE inputs. ? Internally, the 4017 contains five bi-stable subunits. These are interconnected in a pattern known as a Johnson counter.

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The outputs of the bi-stables are decoded to give the ten individual outputs. Operating voltages and currents of 4017 Timer: ? Minimum-6v ? Maximum-15v ? Max current-15mA ? Max speed of operation-5MHz Pin Configuration: Output waveforms of 4017 Timer: Sensor Interface.. ? What if some Authentic Person want to enter into say some Bank-Locker system in some Banks. ? Here we will provide a unique Identification card. ? We used a sensor to recognize and electronic prototyped platform to switch off the Alarm system. Basic Circuit for Slot Sensor: Slot Sensor Working Principle: It contains an Infrared Light Emitting Diode and an photo transistor. ? When power is supplied to the IR-LED it emits IR rays towards the photo transistor. ? There is a finite voltage drop across resistor. ? In the absence of light, output carrier has high voltage. What is arduino? ? It is an open-sourced free electronic prototyping platform. ? In our project we used the arduino uno microcontroller. ? Uno has five analog inputs. ? Six pwm signal outputs. ? In our project Uno facilitates the use of the slot sensors. Code: ? The code consists of two parts, both mandatory o o ? ? ? 1. setup() 2. loop() etup() is used to set the various ports of the uno as i/o. loop()- this part of the code is run indefinetly. void setup() { pinMode(8,OUTPUT); pinMode(A0,INPUT); pinMode(A1,INPUT); pinMode(A2,INPUT); pinMode(A3,INPUT); Serial. begin(9600); } // sets pin 8 as OUTPUT port. // sets A0-5 // ……. // as INPUTS. They take in analog inputs // from the slot sensors and OpAmp out. /* a communication link between Uno and computer is set at 9600 baud. */ void loop() { int a0=analogRead(A0); int a1=analogRead(A1); int a2=analogRead(A2); // four variables a0-a3 are integer variables // these take in analog input values from the // corresponding ports. nt a3=analogRead(A3); // the input voltage what ever voltage is represented as a 0-1024 bit value. if( ! (a0>300 && a1>300 && a2>300 )) { If(a3>500) { tone(8,1000); buzzer at 8 /* a pwm signal with duty-cycle 50% is sent to a port with a time period of 1sec. */ delay(100); } } noTone(8); Transmitter & Receiver Interface: ? Say in some apartments or malls if we use Laser alarm system, if there is any robbery the alarm should beep at the security guard/control room. ? We will transmit the message to all security systems in the mall/apartment So that we can alert them. We used RF-Transmitter and Receiver to transmit the message. ? We used Encoding and Decoding Schemes for protected transmission. ? For that we used HT12E(Encoder), HT12D(Decoder). ? For Demonstration purpose we are using LED’s to show the received message. Transmitter & Receiver: ? RF module comprises of an RF Transmitter and an RF Receiver. The transmitter/receiver (Tx/Rx) pair operates at a frequency of 434 MHz. ? In this RF system, the digital data is represented as variations in the amplitude of carrier wave. This kind of modulation is known as Amplitude Shift Keying (ASK). An RF transmitter receives serial data and transmits it wirelessly through RF through its antenna connected at pin4. ? The transmission occurs at the rate of 1Kbps - 10Kbps. The transmitted data is received by an RF receiver operating at the same frequency as that of the transmitter. Overall view of Transmitter and Receiver: TWS-434 Transmitter: ? TWS-434: The transmitter output is up to 8mW at 433. 92MHz with a range of approximately 400 foot (open area) outdoors. Indoors, the range is approximately 200 foot ? The TWS-434 transmitter accepts digital inputs, can operate from 1. 5 to 12 Volts-DC Encoder-HT12E: This 18 pin IC consists of 8 address pins and 4 data pins with a transmission enable(TE) and oscillator pins ? Transmission takes place from DOUT pin only when TE pin is grounded. ? Address bits are significant because at the receiver the decoder matches the address bits and latch the output only when address bits are matched. Transmitter Circuit: • The message is present at the Data pins in the form of logic state (1 or 0). • Whenever a data pin is grounded along with TE, a 12 bit message signal is generated with its first 8 bits representing the address state and last 4 bits containing the data. The 0 state is encoded as a pulse higher duration and 1 state is encoded as pulse with shorter duration RWS-434 Receiver: • RWS-434: The receiver also operates at 433. 92MHz, and has a sensitivity of 3uV. The RWS-434 receiver operates from 4. 5 to 5. 5 voltsDC, and has both linear and digital outputs. Decoder-HT12D: ? The decoder receives serial address and data from a RF receiver which catches data through antenna. ? It compares the serial input data 3 times continuously with its local address. If no error or matched codes are found then the input data codes are decoded and then transferred to the output pin. The VT pin also goes high to indicate a Valid Transmission (VT). Soldering: ? ? We used chip sockets for Soldering purpose, So that we can prevent chips burning out while soldering. We used female strip for soldering in order to prevent RF-Transmitter and Receiver from burning off’s. Individual Contributions Nagendra Chowdary Before deciding on this project of LASER based intruder detection and security system, we had ideas about two or three other projects. We sat down in group and took up this project because we could divide work to each and every member in this project.

I came up with the idea of using RF Transmitter and receiver so that in case of intruder detection, we can alarm the security person at some other place. I also spent considerable time on studying about the Slot Sensors which we have used to validate the entry of an authentic person. Apart from this, soldering was not an easy task for us as we were doing it for the first time. We made mistakes during soldering and had to de-soldering the circuit many times. Due to this, we all had to contribute to soldering part in turns.

Circuit assembling was the most important aspect of our project. Earlier we had taken up a circuit from “Electronics For You” magazine. We spent almost two days on assembling that circuit but it didn’t work. After that we decided to change the circuit and instead of using LASER detecting diode, we used photo resistors. We tried to make the circuit simpler, so I studied all the components of the circuit and tried to remove some of them to see if the circuit was still functioning. Apart from this, I compiled the data given by my group members to make the final presentation.

Abhinav Tripathi Id: 201101001. We had decide to make a LASER based intruder detection alarm but I thought that it will be better to make it into a security system to validate the entry of authentic people. For this purpose I thought of making a card swapping system using LED and photoresistors so that when a person comes with a valid card the buzzer should not beep. Later, we searched internet and I decided to use slot sensors for this purpose. All the group members, suggested ways of integrating the buzzer and the sensor interface to ensure desired functionality.

Soldering seemed to be tough task for us. I started with the soldering and was later joined by other group members too. I also made contribution in debugging the circuit several times when it didn’t work. All of us studied about the various components of the circuit. I did focused study of the Timer- 4017 and the encoder used in RF transmitter. Apart from this, I also devoted time to understand the functioning of the slot sensors and finding equivalent resistance for slot sensor circuit, implemented it in our circuit. Srinivas SriVasthav Bontula Id-201101025.

After we decided on the topic that is Laser Based Intruder Alarm. I came up the Circuit . Our first attempt was a failure. In our first attempt we used Voltage Regulator IC-7805 , Phototransistor L14F1, Opamp IC-LM356, Timer IC-555, Transistor – BC548. Then we searched for various others circuits, finally while watching some videos on Laser Alarms We found out a circuit . In our second attempt we connected this circuit and it worked. The components we used in this circuit are - Counter – 4017, instead of Phototransistor in the previous circuits we used a LDR( light dependant

Resistor) , Opamp IC-741. After we finished the basic Laser Circuit we came up with this idea of using an RF Transmitter and Reciever , so that we detect the alarm at the place we want. I also spent some time in studying and understanding the circuit. I did my part in connecting the circuit. We assigned tasks to every member of our group regarding the working principles of Laser Circuit, Transmitter , Reciever , Slot Sensor. My task was to study and understand the working of Laser Alarm circuit. First we connected everything on the Breadboard and checked whether the circuit worked.

And then finally we soldered the RF transmitter and Reciever on the PCB. I also helped in soldering the circuit. Even after we finished everything our circuit didn’t function properly twice or thrice at that time I helped in debugging the circuit. Karan J. Dave ID: 201101019 I was very excited to do project after we decided the project of Laser Based Security Alarm. First of all I tried to find some circuits of such project in Google and YouTube. We found some 2-3 circuits from different source but in 2 of them we chased many problems regarding to buzz on and off alarm. Finally we got one circuit from YouTube.

I studied about chips which are used in that circuit. I studied about LDR, OP-AMP and 4017 TIMER. I got the chance to know about inverting and non-inverting OP-AMP. I studied about 4017 TIMER from its datasheet got from the internet and I had known about that from my friends also. I studied about HT12E (Encoder) which was used in RF-Transmitter and HT12D (Decoder) used in RF-Receiver. I did soldering of some of the circuits. I did circuit assembling and debugging with my friends. I did also resource-management work for our project. I really enjoyed the whole project by doing this all things.

Thanks to you sir for giving us this wonderful opportunity. From our project we have learnt team-work, time-management and we could feel that now we are the engineers. T Pavan Nagaraju Id: 201101024 Initially I helped in connecting a Alarm Based circuit Interface which consists of Voltage Regulator IC-7805 , Phototransistor L14F1, Opamp IC-LM356, Timer IC-555, Transistor – BC548. But we are unable to get The Desired Output from It then We Switched to a circuit that does the work of alarm and many of our group mates were not able to understand the working of IC 4017 Timer.

Which works using Jonson Counter I understood the Concept and working principle of the Jonson Counter Which is basically made of 5 bi-stable (D-Flip flops) I understood that which a Logic from this 10 states of the Jonson Counter the output pins get hot coded high output. And get to know how this reset button be useful and Implemented in this IC 4017 . As This IC 4017 is made of n-MOS I applied my Digital Logic Knowledge and come to know that there will be some Dynamic Hazards. I had soldered the Receiver part in the RF Receiver And understood why encoding is necessary In any signal transmission .

So we can have Bit recovery and Safe Signal transmission. I worked in circuit assembling and debugging circuits. I did the documentation part for the presentation regarding 4017-Timer and Receiver part. Archit Bakliwal ID: 201101005. When we started our project, our key concern was to make a security alarm. But as we proceed further, we also used the idea of slot sensing which is mainly used for the entry of authentic person in banks, buildings etc. But later on, all of sudden, I thought that there is no part of communication in out project. Then everyone realized that we have to do something more than just making an alarm.

So, Then, I, along with one of my friend, came up with the idea of making receiver and transmission interface in our project. Soldering is referred as major part of making a circuit. Initially, it seemed to be difficult task because chips were more likely to burn but as I had a little experience with it, so it didn’t remain a tough task for us. I have also played keen role in assembling the circuit which was not an easy task. I have also contributed in making the circuit and have done detailed study on functionality of various components of the circuit.

Specially regarding Timer4017,LM71 Opamp, HT12e Encoder, HT12d Decoder, RWS 434 receiver, TWS 434 transmitter etc. This detailed study helped me to know about the components and analyzing the circuit for resource management and documentation. DHARMIK THAKKAR Id: 201101006 Our Project was LASER BASED INTRUDER DETECTION ALARM which could be used for security system in building apartments, banks, malls, etc. The project was extended to validate the entry of some authentic person such that a person with valid card enters the buzzer shouldn’t buzz. For this purpose slot sensors were used to keep a check upon valid entry.

The project further used RF Transmitter and Receiver interface so that if some unauthentic entry takes place security system is alerted which was accomplished by glowing LED’s at Receiver interface. My role for the project was study of chips which included analysing availability and functionalities of LDR, TWS TRANSMITTER 434, RWS RECEIVER 434 and DECODER HT12D. I helped my team mates in Soldering purpose as it seemed to be tough task for us. Soldering purpose was successfully accomplished without burning chips by the use of chip sockets and female strips. I collected information regarding various phases i. . Alarm, Sensor and RF Transmitter and Receiver interfaces of our project and analysed the circuit for Resource Management and Documentation that could be used for Slide Preparation. I also helped in Circuit Assembling. Prasoon Id: 201101036 After lots of idea's our group stick to the topic that is Laser Based Intruder Detector Alarm in which we created a body which contained a main circuit that produced voltage when light didn’t fall on the LDR. The circuit contained many component that need to be study so I helped in understanding the function of opamp LM 741.

The material for our project was hard to find sometime so I was the one of the prime candidate for fetching these material. Our circuit also contained audrino board, Slot sensor(for security system) and RF transmitter and receiver these circuits were also hard to make but our group combined to make it look easy. I helped in assembling these circuit many times. Soldering also was a main part of our project which was a difficult task, I helped in many parts of the task also we needed to remove mistake from the circuit and documentation which was also a combined effort, In presentation every one had there slides to make.

At the last it’s a combined effort by our group. Ankit Chaparwal ID: 201101017. For the project everybody came up with new innovative ideas, at last we decided to make a laser based intruder detection alarm, but in group discussion we decided to make it in a security system to validate entry of an authentic person. For this purpose we used slot sensors. In the project I helped the Group members in soldering . Other then that I had assembled the receivers circuit with one of the Group members and also prepared Slide for presentation on LDR .

Studied on LDR and thought about how it can be used as a sensor in our circuit. Anuroop Kuppam My involvement in the project , coding the Arduino micro-controller. In our project Arduino provides an interface between the slot sensors and the alarm system. So the micro-controller needs to be coded. The micro-controller takes the input from the slot sensors and then decides whether to enable the alarm system or not. Hence the operating voltages margins of the micro-controller needs to be determined manually.

After this was done we used these margins in making the micro-controller work accordingly. Having seen a lot of coding samples on the INTERNET , I came up with a code which serves the purpose of the project . The code then was debugged in certain places and further processed and fine tuned to fit perfectly and decrease various delays that we have encountered in the course of making the alarm system. I also soldered the various components of the RF receiver and the slot sensor onto the perforated circuit board and debugged the circuit to make it work.

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