Report final

ABSTRACT An accident is a specific, unexpected, unusual and unintended external action which occurs in a particular time and place, with no apparent and deliberate cause but with marked effects. Carelessness of the driver is the major factor of such accidents. The traffic authorities give a lot of instructions to the vehicle operators. But many of them do not obey the rules. Nowadays most of the countries are forcing the motor riders to wear the helmet and not to use the vehicles when the person is in drunken condition. But still the rules are being violated by the users. In order to overcome this, we introduce an intelligent system, Smart Helmet, which automatically checks whether the person is wearing the helmet and has non- alcoholic breath while driving. Here we have a transmitter at the helmet and the receiver at the bike. There is a switch used to sure the wearing of helmet on the head. The ON condition of the switch ensures the placing of the helmet in proper manner. An alcohol sensor is placed near to the mouth of the driver in the helmet to detect the presence of alcohol. The engine should not ON if any of the two conditions is violated. When the rider crashes and the helmet hit the ground, the sensors sense and gives to controller board, the controller extract GPS data using GPS module that is interfaced to it. When the data exceeds the minimum stress limit then GSM module automatically sends message to ambulance or family members.

i

LIST OF CONTENTS Topic Name

PAGE NO

● Abstract

i

● List of figures

vi

● List of tables

viii

CHAPTER 1: INTRODUCTION 1.1 INTRODUCTION

1

1.2 MOTIVATION OF PROJECT

1

1.3 LITERATURE SURVEY

2

1.4 OBJECTIVE OF THE PROJECT

5

1.5 THESIS ORAGNISATION

6

1.6 APPLICATIONS

6

CHAPTER 2: DESCRIPTION OF PROJECT 2.1 INTRODUCTION

7

2.2 BLOCK DIAGRAM

7

2.3 BLOCK DIAGRAM DESCRIPTION

8

2.4 INTRODUCTION TO 89C52 MICROCONTROLLER

9

2.4.1 FEATURES

9

2.4.2 DESCRIPTION

10

2.4.3 PIN DESCRIPTION

13

2.5 REGULATED POWER SUPPLY

16

2.5.1 INTRODUCTION

16

2.5.2 BLOCK DIAGRAM

16

2.6LCD

17

2.6.1 PIN FUNCTION

18 ii

2.7 MOTOR DRIVE AND MOTOR

20

2.7.1 PRINCIPLES OF OPERATION

20

2.7.2 MOTOR DRIVER L293D

22

2.7.3 WORKING OF L293D

23

2.8LED

23

2.9 MQ 3 SENSOR

24

2.9.1 HOW DOES IT LOOK LIKE

25

2.9.2 WORKING PROCESS

26

2.10 GSM

27

2.10.1 GPRS ACCESS INTERFACES AND

28

REFERENCE POINTS 2.10.2 NETWORK INTERFACING

29

2.10.3 LOGICAL ARCHITECTURE

30

2.11 GPS

31

2.12 SIM808 GSM/GPRS/GPS MODULE

34

2.12.1 FEATURES

35

2.12.2 ELECTRONIC CHARACTERISTICS

36

2.12.3 LED STATUS

36

2.13 RF MODULES

36

2.13.1 433 MHZ RF TRANSMITTER

37

AND RECEIVER MODULE 2.13.2 SPECIFICATION

39

2.14 HT12E ENCODER

39

2.14.1 PIN DIAGRAM AND DESCRIPTION

40

2.14.2 WORKING

41

2.14.3TYPICAL APPLICATION CIRCUIT OF HT12E

41

2.14.4 WORKING FLOWCHART OF HT12E

42

iii

2.15 HT12D DECODER

42

2.15.1 PIN DIAGRAM AND DESCRIPTION

43

2.15.2 WORKING

44

2.15.3 TYPICAL APPLICATION CIRCUIT

45

2.15.4 HT12D DECODER WORKING FLOWCHART

46

2.16 VIBRATION SENSOR

47

2.16.1 FEATURES

47

2.17 BUZZER

47

CHAPTER 3: GENERAL COMPONENTS 3.1 RESISTOR

49

3.1.1 RESISTOR COLOR CODING 3.2POTENTIOMETER

50 50

3.2.1 POTENTIOMETER CONSTRUCTION 3.3 CAPACITORS

51 54

3.3.1 DISC CAPACITORS

54

3.3.2 ELECTROLYTIC CAPACITORS

55

3.3.3 COLOR CODING

55

3.3.4 SIX DOT CODE

56

3.4 DIODES

56

3.5 TRANSISTOR

57

3.5.1 NAMING THE TRANSISTOR TERMINALS

58

3.5.2 CHARACTERISTICS OF TRANSISTORS

58

3.6 RELAY

59

3.6.1 BASIC DESIGN AND OPERATION CHAPTER 4: PCBDESIGNING & SOLDERING TECHNIQUES iv

60

4.1: PCB DESIGNING

62

4.2: SOLDERING TECHNIQUES

63

CHAPTER 5: FLOW CHART 5.1 FLOW CHART

66

CHAPTER 6: RESULTS AND DISCUSSION 6.1 INTRODUCTION

68

6.2 SIMULATION AND TEST RESULTS

68

CHAPTER 7: ADVANTAGES AND LIMITATIONS 7.1 INTRODUCTION

70

7.2 ADVANTAGES

70

7.3 LIMITATIONS

70

CHAPTER 8: FUTURE SCOPE AND CONCLUSION 8.1 INTRODUCTION

71

8.2 FUTURE SCOPE

71

8.3 CONCLUSION

71

REFERENCES

72

LIST OF FIGURES Name of figure

Page no v

2.2.1 Block diagram of Project

7

2.4.1 89c51 Pin Configuration

11

2.4.2 Block diagram of 89c51

14

2.5.1Regulated Power Supply

16

2.5.2 Circuit diagram of Regulated Power Supply

17

2.6.1 Liquid Crystal Display

20

2.7.1 Internal structure DC motor

21

2.8.2 DC Motor

21

2.7.3 Pin diagram of L293D

22

2.8.1 Inside a LED

23

2.8.2 Parts of LED

23

2.8.3 Electrical Symbol & Polarities of LED

24

2.9.1 MQ 3 Sensor

25

2.9.2 MQ 3Sensor Internal

26

2.9.3 MQ 3 Working

26

2.9.4 MQ 3 Sensor Behavior

27

2.10.1 GPRS Access Interface

29

2.10.2 GPRS Architecture

30

2.11.1 SIM 808

35

2.13.1 RF Module

38

2.14.1 HT12E Block Diagram

39

2.14.2 HT12E Pin Diagram

40

2.14.3 Oscillator of HT12E

40

2.14.4 Transmission timing for the HT12E

41

2.14.5 Typical Application Circuit of HT12E

41

2.14.6 Working Flowchart of HT12E

42

2.15.1 HT12d Block Diagram

43 vi

2.15.2 HT12E Pin Diagram

43

2.15.3 Oscillator of HT12D

44

2.15.4 HT12D Decoder Timing

44

2.15.5 Typical Application Circuit of HT12D

45

2.15.6 HT12D Decoder working Flowchart

46

2.16.1 Vibration Sensor

47

2.14.1 Buzzer

48

3.1.1 Resistors

49

3.1.2 Color code for Resistor

50

3.2.1 Potentiometer construction

51

3.2.2 Types of potentiometer

52

3.2.3 Electronic symbol for potentiometer

52

3.2.4 Circuit for potentiometer

53

3.3.1 Disk Capacitors

54

3.3.2 Electrolytic Capacitor

55

3.4.1 Diodes

56

3.5.1 Transistor

57

3.6.1 Relay

59

4.1.1 PCB Designing

62

4.2.1 Soldering Iron

64

4.2.2 PCB Erasing

64

4.2.3 Soldering

64

4.2.4 Extended Leg Trimming

65

5.1.1 Flow Chart of System Before Ignition

66

5.1.2 Flow Chart of System After Ignition

67

6.2.1 Initial setup when power is ON

68

6.2.2 Confirmation of wearing helmet

69

vii

6.2.3 Alcohol Detection

69

6.2.4 Accident Detection

69 LIST OF TABLES

Table Name

Page No.

2.4.1Port 1 of 89c51

13

2.4.2 Port 3 of 89c52

14

2.6.1 Pin Function of LCD

18

2.7.1 Pin Function of L293D20

22

2.12.1 Electronic Characteristic of SIM 808

36

2.12.2 LED Status SIM 808

36

viii

Chapter 1 INTRODUCTION 1.1 Introduction: An accident is a specific, unexpected, unusual and unintended external action which occurs in a particular time and place, with no apparent and deliberate cause but with marked effects. Carelessness of the driver is the major factor of such accidents. The traffic authorities give a lot of instructions to the vehicle operators. But many of them do not obey the rules. Nowadays most of the countries are forcing the motor riders to wear the helmet and not to use the vehicles when the person is in drunken condition. But still the rules are being violated by the users. In order to overcome this, we introduce an intelligent system, which automatically checks whether the person is wearing the helmet and has non- alcoholic breath while driving. Here helmet in proper manner. An alcohol sensor is placed near to the mouth of the driver in the helmet to detect the presence of alcohol. The data to be transferred is coded with RF encoder and transmitted we have a transmitter at the helmet and the receiver at the bike. There is a switch used to sure the wearing of helmet on the head. The ON condition of the switch ensures the placing of the through radio frequency transmitter. The receiver at the bike receives the data and decodes it through RF decoder. The engine should not ON if any of the two conditions is violated. MCU controls the function of relay and thus the ignition, it controls the engine through a relay and a relay interfacing circuit. 1.2 Motivation of the project: The idea of developing this project comes from social responsibility towards the society. Bike riding is a lot of fun, but accidents happen. People choose motor bikes over car as it is much cheaper to run, easier to repair, easier to park and flexible in traffic. In India more than 37 million people are using two wheelers. Since usage is high accident percentage of two wheelers are also high compared to four wheelers. Motorcycles have high rate of fatal accidents than cars or trucks and buses. This project aims for accident avoidance, safety and security of bike rider. The main purpose of the project is to encourage wearing helmet. The system will ensure

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that the motorbike will not start unless the rider is wearing a helmet and has not consumed alcohol. Thus, alcohol detection is also an important part in this project. Alcohol detections done by MQ3 sensor and helmet detections done by pressure switch. The system will also alert the bike rider if any obstacle comes too close while riding the bike. This is found to be useful at night or when the riders drowsy or tired. By this accident can be prevented. Also, GSM technology is used to inform the family members in case of an accident. Accident detection is done using accelerometer. Wireless communication through Ask module is done between the helmet and motorbike.

1.3 Literature Survey: 1.3.1 SMART HELMET FOR TWO-WHEELERS Ravi Nandu and Kuldeep Singh SRM University, Department of Automobile Engineering, Kattankulathur, Chennai-603203, India According to this paper on smart helmet the authors describes

Abstract: Helmet is the most important safety gear for two-wheeler riders. But due to carelessness of people and paying less importance toward safety, there are much causality every year. Especially in countries like India; these accidents are common due to ignorance toward safety. According to National Crime Records Bureau (NCRB), two wheelers claimed 92 lives every day out of which most were due to helmetless drive. Many seminars and road safety campaign were organized but still there is very less improvement. The most people who met accident were youngsters. So In order to overcome this problem we came up with the idea of SMART HELMET. The smart helmet will help to reduce the injuries to head. The smart helmet will be different in many ways. It will be technically advanced and electronically controlled. The system design will be such that without wearing the helmet the rider cannot start two wheelers. The helmet will be connected to vehicle key ignition systems, which will be electronically controlled. The smart helmet will be having proximity sensor fitted inside it, which will act as our switch for on/off ignition and further with wireless connection the helmet sensor circuit will be connected to the vehicle ignition system. If the rider is wearing the helmet he will be able to crank the engine

2

and could propel, where as in case if helmet is not there then vehicle will cannot start. This will surely reduce the no of fatalities on road and hence giving a safer drive.

1.3.2 DESIGN OF ACCURATE NAVIGATION SYSTEM BY INTEGRATING INS AND GPS USING EXTENDED KALMAN FILTER Santhosh Kumar MS. Suganthi Assistant professor, Department of TEC, PES institute of technology, Bangalore, Karnataka. According to this paper on GPS and GSM the authors present

Abstract: MEMS based Inertial Measurement Unit (IMU) has been the primary sensor for measuring attitude of unmanned Aerial Vehicles. However, inertial measurements drift in time because the basic parameters have been obtained by dead reckoning wherein the parameters are obtained from integration, so an external aid like the GPS (Global positioning system) has been traditionally used to correct the measurements periodically. This project proposes to demonstrate this application in real time using GPS as an external aid in the correction process. Towards this extended kalman filter (EKF) is proposed to be realized in real time. International Research Journal of Engineering and Technology (IRJET) Volume: 04 Issue: 04 | Apr -2017 Summary: In this paper, the author has improved the GPS tracking using extended kalman filter. Now a Days the GPS modules have been more efficient and tracking the location with great Accuracy. We used this study, as GPS is one the important feature in Smart helmet.

1.3.3 SMART HELMET Mr. Vivek A. Patel1, Mr. Akash Mishra2, Mr. Rana Hiten3, Mr. Kautik Prajapati4 1Assistant professor, electrical Engg, Mahavir Swami College of Engg. & Tec, Surat, Gujarat, India 2, 3, 4 Student, electrical Engg. Mahavir Swami College of Engg. & Tec, Surat, Gujarat, India According to these authors, there is a great need in smart technology to be implemented in

3

smart helmet and they have come up with many features

Abstract Two-wheeler have high rate of accidents than cars or trucks and buses. The aim of smart helmet is to Provide Safety to the bike rider. With the help of Proper Switch Mounted inhelmet, the two-wheeler would not start without helmet so safety of rider is assured and ifaccident hasoccurred our system will give information to the ambulance about the accident, so they can takecertain measures to save the life of the person who meet with an accident. Itis developed usingArduino. We place sensors in different sides of helmet, which isconnected to Arduino board.Therefore, when the bike rider crashes sensors sense and theArduino extract GPS location datausing the GPS, which is interfaced with Arduino. Whenthe sensor data exceeds maximum limitof pressure then GSM module automatically sendsmessage to ambulance, police and familymembers. In case of minor injuries, the rider canstop sending of message by the SMS sending stop switch. I. To design system that can improve bike rider safety. II. To design system reduces number of accident due to the drink and drive. III. To design system that ensure that the rider has were the helmet IV. To design system that reduces the loss of life due to late arrival of the ambulance.

1.3.4 Smart Helmet Using GSM &GPS Technology for Accident Detection and Reporting System International Journal of Electrical and Electronics Research Month: October - December 2014 Manjesh N M Tech, ECE-DSCE, JNTUA, Hindupur, India Prof. Sudarshan Raj. HOD & Asst. Prof. BIT-IT, Hindupur, India

Abstract A smart helmet is a special idea, which makes motorcycle driving safer than before. This isimplemented using GSM and GPS technology. The working of this smart helmet is verysimple; vibration sensors are placed in different places of helmet where the probability ofhitting is more, which are connected to microcontroller board. Therefore, when the ridercrashes and thehelmet hit the ground, these sensors sense and gives to the microcontrollerboard, then controllerextract GPS data using the GPS module that is interfaced to it. Whenthe data exceeds minimumstress limit then GSM module automatically sends message toambulance or family members.Considering

4

three major factors for avoiding the accident causes such as I. Make wearing the helmet compulsory. II. Avoid drunk and drive. III. If person met with an accident, no one is there to help him. Simply leaving or ignoring the person, he may die. In such situation, informing to ambulance or family members through mobile to rescue him for an extent.

1.4 Objective of the Project: Existing System: The existing project basically has a wireless telecommunication, and is connected to a smart phone. This prototype uses sensors to detect a crash or accidents and the communication hardware is used to automatically dial a predefined emergency contact. Thus, helping the victim to reach doctors as early as possible. The other existing system is to control the speed in which the biker is going in. The helmet is fixed with all the components and sensors that read the speed of the bike and accordingly instruct the rider to reduce or increase the speed based on the obstacles ahead the bike. Along with the speed limit sensors the helmet also checks if the rider is drunk and driving.

Proposed System: Security in travel is primary concern for everyone. This Project describes adesign of effective alarm system that can monitor an automotive / vehicle / car condition in traveling. This project is designed to inform about an accident that is occurred to a vehicle to the family members of the traveling persons. This project uses a piezo-electric sensor which can detect the abrupt vibration when an accident is occurred. This sends a signal to microcontroller. This Project presents an automatic vehicle accident detection system using GPS and GSM modems. The system can be interconnected with the car alarm system and alert the owner on his mobile phone. This detection and messaging system is composed of a GPS receiver, Microcontroller and a GSM Modem. GPS Receiver gets the location information from satellites in the form of latitude and longitude.

5

1.5 Thesis Organization The thesis explains the implementation of ―"Two-Wheeler Accident Detection and Prevention System" using microcontroller. The organization of the thesis is explained here with: Chapter 1 Presents introduction to the overall thesis and the overview of the project. In the project overview. Chapter 2 Presents the hardware description. It deals with the block diagram of the project and explains the purpose of each block. In the same chapter the explanation of Microcontroller, Alcohol sensor, power supplies, buzzer, DC motor and LCD,LED are considered. Chapter 3 Presents information of general components such as Resistor, Potentiometer, Capacitor etc. Chapter 4 Presents PCB Designing & Soldering Techniques. Chapter 5 Presents Flow Chart of system. Chapter 6 Presents Result and discussion. Chapter 7 Presents the advantages and limitations of the project. Chapter 8 Presents the conclusion and future scope of the project. Chapter 8 Presents the references of the project. Chapter 8 Presents the appendix.

1.6 Applications 1.

The system will ensure that the motorbike will not start unless the rider is wearing a helmet and has not consumed alcohol. Hence safety of person is ensured.

2.

Also, GSM technology is used to inform the family members in case of an accident. This project could be highly developed with upcoming technologies to provide further more safety and security to the vehicle systems.

6

Chapter 2 DESCRIPTION OF THE PROJECT 2.1 Introduction: In this chapter we will see the block diagram and hardware description of the project in brief.

2.2Block Diagram The following figure shows the independent modules which are considered in this project. Bike Unit

Helmet Unit

7

Fig 2.2: Block diagram of Project

2.3 Block Diagram Description: There are two units in the system namely 

Bike Unit



Helmet Unit

A] Bike Unit: Bike module is integrated with Microcontroller, Vibration sensor. GPS (Global positioning system)and the GSM (Global System for Mobile) modules are also integrated in the Bike module. Vibration Sensor: Vibration sensor is highly sensitive with extremely fast response time. The sensor will output a low logic voltage when vibration is detected. GSM/GPS module: TheGSM Module allowsto send and receive SMS using GSM Library. GPS is used to detect the Latitude and Longitude of any location on the Earth, with exact UTC time.Whenever there is an occurrence of an accident, GPS Receiver used for detecting coordinates of the vehicle, and GSM module is used for sending the coordinates to rider’s emergency contacts by SMS B] Helmet Unit: Helmet module is integrated with the Pressure Switch and Alcohol Sensor. Flex sensor: The Flex sensor is used to detect weather the helmet is worn or not. flex sensor will be placed in the helmet module. This sensor works by bending the sensor itself. Alcohol sensor: An alcohol sensor is used to check the alcohol consumption by the rider. The output value of

8

this sensor will be given as input to the microcontroller. If the rider is found to have consumed alcohol, then the microcontroller prevents the ignition of the bike under this case. The main blocks of the project are 1. 89C52 Microcontroller 2. Alcohol Sensor 3. Pressure Switch 4. LCD Display 5. Vibration Sensor 6. GPS/GSM Module 7.Regulated Power Supply (RPS)

2.4Introduction to 89c52 Microcontroller 2.4.1 Features • Compatible with MCS-51™ Products • 8K Bytes of In-System Reprogrammable Flash Memory • Endurance: 1,000 Write/Erase Cycles • Fully Static Operation: 0 Hz to 24 MHz • Three-level Program Memory Lock • 256 x 8-Bit Internal RAM • 32 Programmable I/O Lines • Three 16-bit Timer/Counters • Eight Interrupt Sources • Programmable Serial Channel • Low Power Idle and Power Down Modes

9

2.4.2 Description: The AT89C52 is a low-power, high-performance CMOS 8-bit microcomputer with 8Kbytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry standard 80C51 and 80C52 instruction set and pinot. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C52 is a powerful microcomputer which provides a highly flexible and cost-effective solution to many embedded control applications.

10

Fig 2.4.1: Pin Configuration

11

Fig 2.4.2: Block diagram of 89C52

The AT89C52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM,32 I/O lines three 16-bittimer/counters, a six-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89C52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM , timer/counters, serial port, and interrupt system to continue functioning. The Power Down Mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next hardware reset.

12

2.4.3 Pin Description VCC Supply voltage. GND Ground. Port 0 Port 0 is an 8-bit open drain bidirectional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high impedance inputs. Port 0 can also be configured to be the multiplexed low order address/data bus during accesses to external program and data memory. In this mode, P0 has internal pull-ups. Port 0 also receives the code bytes during Flash programming and outputs the code bytes during program verification. External pull-ups are required during program verification. Port 1 Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. In addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count input (P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX), respectively, as shown in the following table. Table 2.4.1 Port 1 89c52 Port Pin

Alternate Functions

P1.0

T2 (external count input to Timer/Counter 2), clockout

P1.1

T2EX (Timer/Counter 2 capture/reload trigger and direction control)

13

Port 2 Port 2 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that uses 16-bit addresses (MOVX @ DPTR). In this application, Port 2 uses strong internal pull-ups when emitting 1s. During accesses to external data memory that uses 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-order address bits and some control signals during Flash programming and verification. Port 3 Port 3 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins, they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pull-ups. Port 3 also serves the functions of various special features of the AT89C51, as shown in the following table. Port 3 also receives some control signals for Flash programming and verification. Table 2.4.2 Port 3 89c52 Port Pin

Alternate Functions

P3.0

RXD (serial input port)

P3.1

TXD (serial output port)

P3.2

INT0 (external interrupt 0)

P3.3

INT1 (external interrupt 1)

P3.4

T0 (timer 0 external input)

P3.5

T1 (timer 1 external input)

P3.6

WR (external data memory write strobe)

P3.7

RD (external data memory read strobe)

14

RST Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. ALE/PROG Address Latch Enable is an output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation, ALE is emitted at a constant rate of 1/6 the oscillator frequency and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external data memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode. PSEN Program Store Enable is the read strobe to external program memory. When the AT89C52 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory. EA/VPP External Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for internal program executions. This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming when 12-volt programming is selected. XTAL1 Input to the inverting oscillator amplifier and input to the internal clock operating circuit. XTAL2 Output from the inverting oscillator amplifier.

15

2.5 Regulated Power Supply 2.5.1 Introduction: Power supply is a supply of electrical power. A device or system that supplies electrical or other types of energy to an output load or group of loads is called a power supply unit or PSU. The term is most commonly applied to electrical energy supplies, less often to mechanical ones, and rarely to others. A power supply may include a power distribution system as well as primary or secondary sources of energy such as ● Conversion of one form of electrical power to another desired form and voltage, typically involving converting AC line voltage to a well-regulated lower-voltage DC for electronic devices. ● Low voltage, low power DC power supply units are commonly integrated with the devices they supply, such as computers and household electronics. ● Batteries. ● Chemical fuel cells and other forms of energy storage systems. ● Solar power. ● Generators or alternators. ●

2.5.2 Block Diagram:

Fig 2.5.1: Regulated Power Supply The basic circuit diagram of a regulated power supply (DC O/P) with led connected as load is shown in fig: 3.6

16

Figure 2.5.2: Circuit diagram of Regulated Power Supply with Led connection

The components mainly used in above figure are ● 230v AC mains ● Transformer ● Bridge rectifier(diodes) ● Capacitor ● Voltage regulator (IC 7805) ● Resistor ● LED (light emitting diode)

2.6 Liquid Crystal Display LCD stands for Liquid Crystal Display. LCD is finding widespread use replacing LEDs (seven segment LEDs or other multi segment LEDs) because of the following reasons: 1. The declining prices of LCDs. 2. The ability to display numbers, characters and graphics. This is in contrast to LEDs, which are limited to numbers and a few characters. 3. Incorporation of a refreshing controller into the LCD, thereby relieving the CPU of the task of refreshing the LCD. In contrast, the LED must be refreshed by the CPU to keep displaying the data. 4. Ease of programming for characters and graphics.

17

These components are “specialized” for being used with the microcontrollers, which means that they cannot be activated by standard IC circuits. They are used for writing different messages on a miniature LCD. A model described here is for its low price and great possibilities most frequently used in practice. It is based on the HD44780 microcontroller (Hitachi) and can display messages in two lines with 16 characters each. It displays all the alphabets, Greek letters, punctuation marks, mathematical symbols etc. In addition, it is possible to display symbols that user makes up on its own. Automatic shifting message on display (shift left and right), appearance of the pointer, backlight etc. are considered as useful characteristics.

2.6.1 PINS FUNCTIONS: There are pins along one side of the small printed board used for connection to the microcontroller. There are total of 14 pins marked with numbers (16 in case the background light is built in). Their function is described in the table below:

Table 2.6.1 Pin Function of LCD Description

Logic

0V +5V 0 - Vdd D0 – D7 are interpreted as

State 0

commands

1

D0 – D7 are interpreted as data Write data (from controller to

0

LCD)

1

Read data (from LCD to controller) Access to LCD disabled

0

Normal operating

1

Name

Pin

Function

Vss Vdd Vee RS

Number 1 2 3 4

Ground Power supply Contrast Control of operating

18

R/W

5

E

6

Data/commands are transferred to

From 1 to

LCD Bit 0 LSB Bit 1 Bit 2 Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 MSB

0 0/1 0/1 0/1 0/1 0/1 0/1 0/1 0/1

D0 D1 D2 D3 D4 D5 D6 D7

7 8 9 10 11 12 13 14

Data / commands

LCD SCREEN: LCD screen consists of two lines with 16 characters each. Each character consists of 5x7 dot matrix. Contrast on display depends on the power supply voltage and whether messages are displayed in one or two lines. For that reason, variable voltage 0-Vdd is applied on pin marked as Vee. Trimmer potentiometer is usually used for that purpose. Some versions of displays have built in backlight (blue or green diodes). When used during operating, a resistor for current limitation should be used (like with any LE diode).

Fig:2.6.1 Liquid Crystal Display

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2.7 MOTOR DRIVE & MOTOR: Here DC Motor is used to rotate the panel in the required direction. Let us study in detail about the DC Motor.

2.7.1 Principles of Operation In any electric motor, operation is based on simple electromagnetism. A current-carrying conductor generates a magnetic field; when this is then placed in an external magnetic field, it will experience a force proportional to the current in the conductor, and to the strength of the external magnetic field. The internal configuration of a DC motor is designed to harness the magnetic interaction between a current-carrying conductor and an external magnetic field to generate rotational motion. Let's start by looking at a simple 2-pole DC electric motor (here red represents a magnet or winding with a "North" polarization, while green represents a magnet or winding with a "South" polarization).

Fig 2.7.1 Internal structure DC motor Every DC motor has six basic parts. They are axle, rotor (a.k.a., armature), stator, commutator, field magnet(s), and brushes. In most common DC motors (and all that BEAMERS will see), the external magnetic field is produced by high-strength permanent magnets. The stator is the stationary part of the motor -- this includes the motor casing, as well as two or more permanent magnet pole pieces. The rotor (together with the axle and attached commutator) rotates with respect to the stator. The rotor consists of windings (generally on a core), the windings being electrically connected to the commutator. The above diagram shows a common motor layout with the rotor inside the stator (field) magnets. The geometry of the brushes, commutator contacts, and rotor windings are such that when power is applied, the polarities of the energized winding and the stator magnet(s) are misaligned, and the rotor will rotate until it is almost aligned with the stator's field magnets. As the rotor

20

reaches alignment, the brushes move to the next commutator contacts, and energize the next winding. Given our example two-pole motor, the rotation reverses the direction of current through the rotor winding, leading to a "flip" of the rotor's magnetic field, driving it to continue rotating.

Figure 2.7.2 DC Motor Consider a DC motor. A DC motor [4] will have two terminals. Let the terminals are D1 and D2. If we give positive voltage to D1 and negative voltage to D2 (simply voltage at D1 should be more positive than the voltage at D2) the rotor will rotate in forward direction. Alternatively, if the voltage at D1 is negative and D2 is positive (or in other words voltage at D1 is more negative than D2) then the motor will rotate in reverse direction.

2.7.2MOTOR DRIVER L293D

Figure 2.7.3 Pin diagram of L293D

21

Table 2.7.1 Pin Function of L293D Name

Function

Enable 1,2 Input 1 Output 1 Ground Ground Output 2 Input 2 Vcc2 Enable 3,4 Input 3 Output 3 Ground Ground Output 4 Input 4 Vcc1

Enable pin for Motor 1;active high Input 1 for Motor 1 Output 1 for Motor 1 Ground(0V) Ground(0V) Output 2 for Motor 1 Input 2 for Motor 1 Supply voltage for Motors;9-12V(upto 36V) Enable pin for Motor 2; active high Input 1 for Motor 1 Output 1 for Motor 1 Ground (0V) Ground(0V) Output 2 for Motor 1 Input 2 for Motor 1 Supply voltage; 5V(upto 36V)

Pin No 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

2.7.3 Working of L293D The 4 input pins for this L293d, pin 2,7 on the left and pin 15 ,10 on the right as shown on the pin diagram[5]. Left input pins will regulate the rotation of motor connected across left side and right input for motor on the right-hand side. The motors are rotated on the basis of the inputs provided across the input pins as LOGIC 0 or LOGIC 1. In simple you need to provide Logic 0 or 1 across the input pins for rotating the motor.

2.8 LED: A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices, and are increasingly used for lighting. Introduced as a practical electronic component in 1962, early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet and infrared wavelengths, with very high brightness. The internal structure and parts of a led are shown in figures 2.9.1 and 2.9.2 respectively.

22

Fig 2.8.1: Inside a LED Fig 2.8.2:Parts of LED Working: The structure of the LED light is completely different than that of the light bulb. Amazingly, the LED has a simple and strong structure. The light-emitting semiconductor material is what determines the LED's color. The LED is based on the semiconductor diode. When a diode is forward biased (switched on), electrons are able to recombine with holes within the device, releasing energy in the form of photons. This effect is called electroluminescence and the color of the light (corresponding to the energy of the photon) is determined by the energy gap of the semiconductor. An LED[6] is usually small in area (less than 1 mm2), and integrated optical components are used to shape its radiation pattern and assist in reflection. LEDs present many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved robustness, smaller size, faster switching, and greater durability and reliability. However, they are relatively expensive and require more precise current and heat management than traditional light sources. Current LED products for general lighting are more expensive to buy than fluorescent lamp sources of comparable output. They also enjoy use in applications as diverse as replacements for traditional light sources in automotive lighting (particularly indicators) and in traffic signals. The compact size of LEDs has allowed new text and video displays and sensors to be developed, while their high switching rates are useful in advanced communications technology. The electrical symbol and polarities of led are shown in fig: 2.10.3.

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Fig 2.8.3: Electrical Symbol & Polarities of LED

2.9MQ3 Sensor: This is an alcohol sensor from futurlec, named MQ-3, which detects ethanol in the air. It is one of the straightforward gas sensors so it works almost the same way with other gas sensors. Typically, it is used as part of the breathalyzers or breath testers for the detection of ethanol in the human breath.

Fig 2.9.1: MQ3 Sensor

2.9.1 How does it look like: Basically, it has 6pins, the cover and the body. Even though it has 6 pins, you can use only 4 of them. Two of them are for the heating system, which I call H and the other 2 are for

24

connecting power and ground, which I called A and B. If you look at the inside of the sensor, you will find the little tube. Basically, this tube is a heating system that is made of aluminum oxide and tin dioxide and inside of it there are heater coils, which practically produce the heat. And you can also find 6 pins. 2 pins that I called Pin H are connected to the heater coils and the other ones are connected to the tube.

Fig 2.9.2: MQ3 Sensor internal

2.9.2 Working Process: How does it work? The core system is the cube. As you can see in this cross-sectional view, basically, it is an Alumina tube cover by SnO2, which is tin dioxide. And between them there is an Aurum electrode, the black one. And also, you can see how the wires are connected. So, why do we need them? Basically, the alumina tube and the coils are the heating system, the yellow, brown parts and the coils in the picture.

25

Fig 2.9.3: MQ3 Sensor working If the coil is heated up, SnO2 ceramics will become the semi - conductor, so there are more movable electrons, which means that it is ready to make more current flow. Then, when the alcohol molecules in the air meet the electrode that is between alumina and tin dioxide, ethanol burns into acetic acid then more current is produced. So the more alcohol molecules there are, the more current we will get. Because of this current change, we get the different values from the sensor.

Fig 2.9.4: MQ3 Sensor behavior

2.10 GSM: GSM is a mobile communication modem; it is stands for global system for mobile communication (GSM). The idea of GSM was developed at Bell Laboratories in 1970.  It is widely used mobile communication system in the world. GSM is an open and digital cellular technology used for transmitting mobile voice and data services operates at the 850MHz, 900MHz, 1800MHz and 1900MHz frequency bands.GSM system was developed as a digital system using time division multiple access (TDMA) technique for communication purpose. A GSM digitizes and reduces the data, then sends it down through a channel with two different

26

streams of client data, each in its own particular time slot. The digital system has an ability to carry 64 kbps to 120 Mbps of data rates. GPRS uses a packet-mode technique to transfer high-speed and low-speed data and signaling in an efficient manner. GPRS optimizes the use of network and radio resources. Strict separation between the radio subsystem and network subsystem is maintained, allowing the network subsystem to be reused with other radio access technologies. GPRS does not mandate changes to an installed MSC base. New GPRS radio channels are defined, and the allocation of these channels is flexible: from 1 to 8 radio interface timeslots can be allocated per TDMA frame, timeslots are shared by the active users, and up and downlink are allocated separately. The radio interface resources can be shared dynamically between speech and data services as a function of service load and operator preference. Various radio channel coding schemes are specified to allow bitrates from 9 to more than 150 kbit/s per user. Applications based on standard data protocols are supported, and interworking is defined with IP networks and X.25 networks. GPRS allows SMS transfer over GPRS radio channels. GPRS is designed to support from intermittent and bursty data transfers through to occasional transmission of large volumes of data. Several quality of service profiles are supported. GPRS is designed for fast reservation to begin transmission of packets, typically 0,5 to 1 second. Charging should typically be based on the amount of data transferred. Three GPRS MS modes of operation are supported: An MS in class-A mode of operation operates GPRS and other GSM services simultaneously. An MS in class-B mode of operation monitors control channels for GPRS and other GSM services simultaneously, but can only operate one set of services at one time. An MS in class-C mode of operation exclusively operates GPRS services. GPRS introduces two new network nodes in the GSM PLMN: The Serving GPRS Support Node (SGSN), which is at the same hierarchical level as the MSC, keeps track of the individual MSs' location and performs security functions and access control. The SGSN is connected to the base station system with Frame Relay. The Gateway GSN (GGSN) provides interworking with external packet-switched networks, and is connected with SGSNs via an IPbased GPRS backbone network. The HLR is enhanced with GPRS subscriber information, and the SMS-GMSCs and SMS-IWMSCs are upgraded to support SMS transmission via the SGSN. Optionally, the MSC/VLR can be enhanced for more-efficient co-ordination of GPRS and nonGPRS services and functionality: e.g., paging for circuit-switched calls that can be performed more efficiently via the SGSN, and combined GPRS and non-GPRS location updates. GPRS security functionality is equivalent to the existing GSM security. The SGSN performs 27

authentication and cipher setting procedures based on the same algorithms, keys, and criteria as in existing GSM. GPRS uses a ciphering algorithm optimized for packet data transmission. A GPRS ME can access the GPRS services with SIMs that are not GPRS-aware, and with GPRSaware SIMs.

2.10.1 GPRS Access Interfaces and Reference Points: Each GPRS PLMN has two access points, the Um used for mobile access and the R reference point used for origination or reception of messages. The R reference point for the GPRS MSs is defined in GSM 07.60. An interface differs from a reference point in that an interface is defined where specific GPRS information is exchanged and needs to be fully recognized. There is an inter-GPRS PLMN interface called Gp that connects two independent GPRS networks for message exchange. There is also a GPRS PLMN to fixed network (typically a packet data network) reference point called Gi. Gi is defined in GSM 09.61[19].

Fig:2.10.1 GPRS Access Interfaces There may be more than a single GPRS network interface to several different packet data (or other) networks. These networks may both differ in ownership as well as in communications protocol (e.g., X.25, TCP/IP etc.). The network operator should define and negotiate interconnect with each external (PDN or other) network.

2.10.2 Network Interfacing: Network interworking is required whenever a PLMN supporting GPRS and any other network are involved in the execution of a GPRS service request. With reference to figure 1, interworking takes place through the Gi reference point and the Gp interface[20]. The GPRS

28

internal mechanism for conveying the PDP PDU through the GSM PLMN is managed by the GSM GPRS network operator and is not apparent to the data user. The use of this GSM data service may have an impact on and increase the transfer time normally found for a message when communicated through a fixed packet data network.

PSPDN Internetworking: GPRS shall support interworking with PSPDN networks. The interworking may be either direct or through a transit network (e.g., ISDN). GPRS shall support both X.121 and E.164 addresses. GPRS shall provide support for X.25 virtual circuits and X.25 fast select. X.75 or X.75' may be used for interworking with X.25 PDNs. The GPRS TEs have addresses provided by the GSM PLMN GPRS service operator and belong to the GPRS service domain. The PSPDN TE sends data to the GPRS TE by use of the GSM PLMN GPRS DNIC (Data Network Identification Code) or equivalent that uniquely identifies the GPRS network.

Internet(IP) Internetworking: GPRS shall support interworking with networks based on the internet protocol (IP). IP is defined in RFC 791. GPRS may provide compression of the TCP/IP header when an IP-datagram is used within the context of a TCP connection. In a similar way to the PSPDN X.25 case, the GSM PLMN GPRS service is an IP domain[21], and mobile terminals offered service by a GSM service provider may be globally addressable through the network operator's addressing scheme

2.10.3 Logical Architecture:

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Fig:2.10.2 GPRS Architecture

2.11 GPS: The Global Positioning System (GPS) is a satellite-based navigation system made up of a network of 24 satellites placed into orbit by the U.S. Department of Defence.  Military actions was the original intent for GPS, however in the 1980s, the U.S. government decided to allow the GPS program to be used by civilians. Weather conditions do not affect the ability for GPS to work. The systems work 24/7 anywhere in the world. There are no subscription fees or setup charges to use GPS.

GPS devices can have capabilities such as: 

Maps, including streets maps, displayed in human readable format via text or in a graphical format,

30



Turn-by-turn navigation directions to a human in charge of a vehicle or vessel via text or speech,



Directions fed directly to an autonomous vehicle such as a robotic probe,



Traffic congestion maps (depicting either historical or real time data) and suggested alternative directions,



Information on nearby amenities such as restaurants, fuelling stations, and tourist attractions.

GPS can able to answer: 

The roads or paths available,



Traffic congestion and alternative routes,



Roads or paths that might be taken to get to the destination,



If some roads are busy (now or historically) the best route to take,



The location of food, banks, hotels, fuel, airports or other places of interests,



The shortest route between the two locations,



The different options to drive on highway or back roads. Of all the applications of GPS, vehicle tracking and navigational systems have brought

this technology to the day-to-day life of the common man. Today GPS fitted cars; ambulances, fleets and police vehicles are common sights on the roads of developed countries. Known by many names such as Automatic Vehicle Locating System (AVLS), Vehicle Tracking and Information System (VTIS), Mobile Asset Management System (MAMS), these systems offer an effective tool for improving the operational efficiency and utilization of vehicles. GPS is used in vehicles for both tracking and navigation. Tracking systems enable a base station to keep track of the vehicles without the intervention of the driver where, as navigation system helps the driver to reach the destination. Whether navigation system or tracking system, the architecture is more or less similar. The navigation system will have convenient, usually a graphic, display for the driver which is not needed for a tracking system. Vehicle Tracking Systems combine a number of well-developed technologies. Irrespective of the technology being used, VTS consist of three subsystems: a) In-vehicle unit (IVU), b) Base station and c) Communication link. The IVU includes a suitable position sensor and an intelligent controller together with an appropriate interface to the communication link. Thanks to the US Government announcement of 911E regulation, radio-based position technology has witnessed a spurt of developmental activities.

31

Network Overlay Systems use cell phone infrastructure for locating vehicles. The cell centres with additional hardware and software assess the time of arrival (TOA) and angle of arrival (AOA) of radio signals from vehicles to compute the position of the vehicles. This information is sent to the tracking centre through the cell link or conventional link. Another technique used for locating vehicles computes the time difference for signals from two cell centres to reach the vehicle. This computation is made in the IVU and the position information is sent to the tracking centre through the cell phone link. A more common technique used is direct radio link (DRL). In this system dedicated radio infrastructure is used along with special IVU to compute vehicle location. However, all these techniques impose limitation on the operational area. Alternatively, embedded GPS receivers provide absolute position co-ordinates at any point, without any area restrictions. Mobile phones with GPS capability: Due in part to regulations encouraging mobile phone tracking, including E911, the majority of GPS receivers are built into mobile telephones, with varying degrees of coverage and user accessibility. Commercial navigation software is available for most 21st-century smart phones as well as some Java-enabled phones that allows them to use an internal or external GPS receiver (in the latter case, connecting via serial or Bluetooth). Some phones using assisted GPS (A-GPS) function poorly when out of range of their carrier's cell towers. Others can navigate worldwide with satellite GPS signals as well as a dedicated portable GPS receiver does, upgrading their operation to A-GPS mode when in range. Still others have a hybrid positioning system that can use other signals when GPS signals are inadequate. More bespoke solutions also exist for smart phones with inbuilt GPS capabilities. Some such phones can use tethering to double as a wireless modem for a laptop, while allowing GPSnavigation/localisation as well. One such example is marketed by Verizon Wireless in the United States, and is called VZ Navigator. The system uses gps One technology to determine the location, and then uses the mobile phone's data connection to download maps and calculate navigational

routes.

Other

products

including iPhone are

used

to

provide

similar

services. Nokia gives Ovi Maps free on its smart phones and maps can be preloaded.According to market research from the independent analyst firm Berg Insight, the sales of GPS-enabled GSM/WCDMA handsets was 150 million units in 2009, while only 40 million separate GPS receivers were sold. GPS navigation applications for mobile phones include on-line (e.g. Waze, Google Maps 32

Navigation) and off-line (e.g. iGo for Android, Maverick and Here (Nokia) for Windows Phone) navigation applications. Google Maps Navigation, which is included with Android, means most smart phone users only need their phone to have a personal navigation assistant. Many Android smart phones have an additional GPS feature, called EPO (Extended Prediction Orbit). The phone downloads a file to help it locate GPS satellites more quickly and reduce the Time To First Fix.

Assisted GPS, as   the Nokia N95, speeds up the TTFF significantly in two ways. The received GPS signals are shifted in frequency due to the relative receiver-satellite motion (Doppler shift). The GPS receiver must find the frequency of the signal before it can lock on. Knowledge of each satellite's position and velocity from an Assisted GPS server effectively reduces the number of frequencies to be searched because there's less guesswork involved, speeding TTFF up by (potentially) tens of seconds. Even more significantly, normally a receiver has to spend at least 20 seconds (and often a lot more) decoding the navigation data from the satellites it can find, before it can start the triangulation calculations to work out a position on the Earth's surface. With Assisted GPS, the navigation data is provided, more or less perfectly (think of it as a crib that the GPS can use). Add the two factors together and it's easy to see that even in worst case, TTFF can be reduced by 30 seconds or so. A final benefit comes from increased receiver sensitivity, which is directly related to the number of frequencies which must be searched to find a satellite signal. Because the GPS receiver has fewer frequencies to search, it can dwell on each for a greater period of time, increasing the effective sensitivity and enabling the GPS to use signal strengths below

33

the normal thresholds to make range measurements (for example in built-up areas where many satellites are blocked by obstructions). At the moment, management of GPS positioning in smartphones is semi-automatic but there's often still a little fiddling to be done by the end user. Once the technology goes mainstream though, I'd expect a fully automatic solution, integrated into the smartphone OS. Ideally, we'd see Assisted GPS use AND intelligent power control of the GPS to only require fixes when position-dependent applications were active and when movement is detected within the GSM cell (to save power). Once this is in place, we get to the situation where every smartphone will effectively know where it is on the planet at all times, with perhaps only a brief (10 seconds or so) 'Please wait' message every now and then when a very exact GPS fix is needed for navigation purposes. The obvious application of GPS services is for providing maps of where you are and directions to get to somewhere else, an area which is well covered at the moment but which will only get more and more strong.

2.12 SIM808 GSM/GPRS/GPS Module: SIM808 module is a GSM and GPS two-in-one function module. It is based on the latest GSM/GPS module SIM808 from SIMCOM, supports GSM/GPRS Quad-Band network and combines GPS technology for satellite navigation. It features ultra-low power consumption in sleep mode and integrated with charging circuit for Li-Ion batteries, that make it get a super long standby time and convenient for projects that use rechargeable Li-Ion battery. It has high GPS receive sensitivity with 22 tracking and 66 acquisition receiver channels. Besides, it also supports A-GPS that available for indoor localization. The module is controlled by AT command via UART and supports 3.3V and 5V logical level.

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Fig:2.11.1 SIM 808

2.12.1 Features: 

Quad-band 850/900/1800/1900 MHz



GPRS multi-slot class12 connectivity: max. 85.6 kbps(down-load/up-load)



GPRS mobile station class B



Controlled by AT Command (3 GPP TS 27.007, 27.005 and SIMCOM enhanced AT Commands)



Supports charging control for Li-Ion battery



Supports Real Time Clock



Supply voltage range 3.4 V ~ 4.4 V



Integrated GPS/CNSS and supports A-GPS



Supports 3.0 V to 5.0 V logic level



Low power consumption, 1 mA in sleep mode



Supports GPS NMEA protocol



Standard SIM Card

35

2.12.2Electronic Characteristics: Table 2.12.1 Electronic Characteristic of SIM 808 Electronic Characteristics Voltage InputVBAT Input voltage VinH (Target Voltage = 3.3V) Input voltage VinH (Target Voltage = 5V) Input voltage VinL Peak Current Average Current

Min 3.4 3 4.5 -0.3 0 2

Typical 3.3 5 0 -

Max 4.4 3.6 5.5 0.5 2 500

Unit VDC V V V A mA

2.12.3LED Status Table 2.12.2 LED Status SIM 808 LED Status Indicator (Green) Net Indicator (Red)

Status Off On Off 64 ms on / 800 ms off 64 ms On / 3000 ms Off 64 ms ON / 3000 ms Off

Function Power of LoNet is off Power of LoNet is on Power of LoNet is off Module can't find the network Module has connected to network GPRS communication

2.13 RF modules: An RF module (short for radio-frequency module) is a (usually) small electronic device used to transmit and/or receive radio signals between two devices. In an embedded system it is often desirable to communicate with another device wirelessly. This wireless communication may be accomplished through optical communication or through radio-frequency (RF) communication. For many applications, the medium of choice is RF since it does not require line of sight. RF communications incorporate a transmitter and a receiver. They are of various types and ranges. Some can transmit up to 500 feet. RF modules are typically fabricated using RF CMOS technology. RF modules are widely used in electronic design owing to the difficulty of designing radio circuitry. Good electronic radio design is notoriously complex because of the sensitivity of radio circuits and the accuracy of components and layouts required to achieve operation on a specific frequency. In addition, reliable RF communication circuit requires careful monitoring of the manufacturing process to ensure that the RF performance is not adversely affected. Finally,

36

radio circuits are usually subject to limits on radiated emissions, and require Conformance testing and certification by a standardization organization such as ETSI or the U.S. Federal Communications Commission (FCC). For these reasons, design engineers will often design a circuit for an application which requires radio communication and then "drop in" a pre-made radio module rather than attempt a discrete design, saving time and money on development. RF modules are most often used in medium and low volume products for consumer applications such as garage door openers, wireless alarm or monitoring systems, industrial remote controls, smart sensor applications, and wireless home automation systems. They are sometimes used to replace older infrared communication designs as they have the advantage of not requiring line-of-sight operation. Several carrier frequencies are commonly used in commercially available RF modules, including those in the industrial, scientific and medical (ISM) radio bands such as 433.92 MHz, 915 MHz, and 2400 MHz. These frequencies are used because of national and international regulations governing the use of radio for communication. Short Range Devices may also use frequencies available for unlicensed such as 315 MHz and 868 MHz.

2.13.1 433 MHz RF transmitter and receiver module: In general, the wireless systems designer has two overriding constraints: it must operate over a certain distance and transfer a certain amount of information within a data rate. The RF modules are very small in dimension and have a wide operating voltage range i.e. 3V to 12V.Basically the RF modules are 433 MHz RF transmitter and receiver modules. The transmitter draws no power when transmitting logic zero while fully suppressing the carrier frequency thus consume significantly low power in battery operation. When logic one is sent carrier is fully on to about 4.5mA with a 3volts power supply. The data is sent serially from the transmitter which is received by the tuned receiver. Transmitter and the receiver are duly interfaced to two microcontrollers for data transfer.

37

Fig:2.13.1 RF Modules

2.13.2Specification: 

Operating frequency: 433MHz



Open space operating range: 400 m with 45 cm antenna



Rx current supply: 3.5 mA



Rx operating voltage: 5V



Rx typical sensitivity: 105Dbm

38



Tx operating voltage: 3-6V



Tx output power: 4-12Dbm



Power consumption: low

2.14 HT12E Encoder HT12E is a 212 series encoder IC (Integrated Circuit) for remote control applications. It is commonly used for radio frequency (RF) applications. By using the paired HT12E encoder and HT12D decoder we can easily transmit and receive 12 bits of parallel data serially. HT12E simply converts 12-bit parallel data in to serial output which can be transmitted through a RF transmitter. These 12-bit parallel data is divided in to 8 address bits and 4 data bits. By using these address pins, we can provide 8-bit security code for data transmission and multiple receivers may be addressed using the same transmitter.

Fig 2.14.1 HT12E Block Diagram HT12E is able to operate in a wide voltage range from 2.4V to 12V and has a built-in oscillator whichrequires only a small external resistor. Its power consumption is very low, standby current is 0.1μA at 5VVDD and has high immunity against noise. It is available in 18 pin DIP (Dual Inline Package) and 20 pinSOP (Small Outline Package) as given below.

2.14.1 Pin Diagram and Description

39

Fig. 2.14.2 HT12E Pin Diagram VDD and VSS are power supply pins which are used to connect positive and negative of the power supply respectively. OSC1 and OSC2 are used to connect external resistance for the internal oscillator. OSC1 is the oscillator input pin and OSC2 is the oscillator output pin.

Fig 2.14.3 Oscillator of HT12E TE is used for enabling the transmission and is an active low input. A0 – A7 are the input address pins. By using these pins, we can provide a security code for the data. These pins can be connected to VSS or left open. D8 – D11 are the input data pins. These pins can be connected to VSS or may left open for sending LOW and HIGH respectively. DOUT – It is the serial data output of the encoder and can be connected to a RF transmitter

2.14.2Working:

40

Fig. 2.14.4Transmission timing for the HT12E The HT12E 2series encoder starts a 4-word transmission cycle upon receiving transmission enable signal on TE input. This output cycle will repeat as long as the transmission is enabled. When the transmission enables (TE) signal switches to HIGH, the encoder output completes the current cycle and stops as shown above. The encoder will be in the Standby mode when the transmission is disabled.

2.14.3Typical Application Circuit of HT12E:

Fig 2.14.5 Typical Application Circuit of HT12E

2.14.4 Working Flowchart of HT12E:

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Fig. 2.14.6 Working Flowchart of HT12E

2.15HT12D Decoder HT12D is a 212 series decoder IC (Integrated Circuit) for remote control applications manufactured by Holtek. It is commonly used for radio frequency (RF) wireless applications. By using the paired HT12E encoder and HT12D decoder we can transmit 12 bits of parallel data serially. HT12D simply converts serial data to its input (may be received through RF receiver) to 12-bit parallel data. These 12-bit parallel data is divided in to 8 address bits and 4 data bits. Using 8 address bits we can provide 8-bit security code for 4-bit data and can be used to address multiple receivers by using the same transmitter.

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Fig2.15.1 HT12d Block Diagram

HT12D is a CMOS LSI IC and is capable of operating in a wide voltage range from 2.4V to 12V. Its power consumption is low and has high immunity against noise. The received data is checked 3 times for more accuracy. It has built in oscillator, we need to connect only a small external resistor. As HT12E, it is available in 18 pin DIP (Dual Inline Package) and 20 pin SOP (Small Outline Package) as given below.

2.15.1 Pin Diagram and Description:

Fig2.15.2 HT12E Pin Diagram

43



VDD and VSS are used to provide power to the IC, Positive and Negative of the power supply respectively. As I said earlier its operating voltage can be in the range 2.4V to 12V



OSC1 and OSC2 are used to connect external resistor for internal oscillator of HT12D. OSC1 is the oscillator input pin and OSC2 is the oscillator output pin as shown in the figure below.

Fig2.15.3 Oscillator of HT12D 

A0 – A7 are the address input pins. Status of these pins should match with status of address pin in HT12E (used in transmitter) to receive the data. These pins can be connected to VSS or left open.



DIN is the serial data input pin and can be connected to a RF receiver output.



D8 – D11 are the data output pins. Status of these pins can be VSS or VDD depending upon the received serial data through pin DIN.



VT stands for Valid Transmission. This output pin will be HIGH when valid data is available at D8 – D11 data output pins.

2.15.2 Working:

Fig2.15.4 HT12D Decoder Timing

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HT12D decoder will be in standby mode initially i.e., oscillator is disabled and a HIGH on DIN pin activates the oscillator. Thus, the oscillator will be active when the decoder receives data transmitted by an encoder. The device starts decoding the input address and data. The decoder matches the received address three times continuously with the local address given to pin A0 – A7. If all matches, data bits are decoded and output pins D8 – D11 are activated. This valid data is indicated by making the pin VT (Valid Transmission) HIGH. This will continue till the address code becomes incorrect or no signal is received.

2.15.3 Typical Application Circuit:

Fig.2.15.5 Typical Application Circuit of HT12D

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2.15.4 HT12D Decoder working Flowchart:

Fig2.15.6 HT12D Decoder working Flowchart

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2.16Vibration Sensor: A high sensitivity vibration sensor often used for security detector. This sensor is highly sensitive with extremely fast response time. The sensor will output a low logic voltage when vibration is detected. The sensitivity can be adjusted with the onboard potentiometer.

Fig2.16.1 Vibration Sensor

2.16.1 Features: 

Working voltage:DC 5-15V



With signal indicate light



Output signal: LOW level when detect vibration



Interface: PH2.54 3pin

2.17 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[23].

47

Fig:2.17.1 Buzzer

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Chapter 3 GENERAL COMPONENTS

3.1 Resistors:

Fig 3.1.1 Resistors In many electronic circuit applications, the resistance forms the basic part of the circuit. The reason for inserting the resistance is to reduce current or to produce the desired voltage drop. These components which offer value of resistance are known as resistors. Resistors may have fixed value i.e., whose value cannot be changed and are known as fixed resistors. Such of those resistors whose value can be changed or varied are known as variable resistors. There are two types of resistors available. They are: 

Carbon resistors.



Wire wound resistors.

Carbon resistors are used when the power dissipation is less than 2W because they are smaller and cost less. Wire wound resistors are used where the power dissipation is more than 5W. In electronic equipment carbon resistors are widely used because of their smaller size. All resistors have three main characteristics: 

Its resistance R in ohms (from 1 ohm to many mega ohms).



Power rating (from several 0.1W to 10 W).

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

Tolerance (in percentage).

3.1.1 RESISTOR COLOR CODING: The carbon resistors are small in size and are color coded to indicate their resistance value in ohms. Different colors are used to indicate the numeric values. The dark colors represent lower values and the lighter colors represent the higher values. The color code has been standardized by the electronic industries association. The color bands are printed at one end of the resistors and are read from the left to right. The first color band closed to the edge indicates the first digit in the value of resistance.Thesecond band gives the second digit. The third band gives the number of zero’s after two digits. The resulting number is the resistance in ohms. A fourth band indicates the tolerance i.e., to indicate how accurate the resistance value is, the bands are shown in the figure 3.2.

Fig. 3.1.2: Color code for Resistor

3.2Potentiometer: A potentiometer, informally a pot, is a three-terminalresistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals are used, one end and the

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wiper, it acts as a variable resistor or rheostat. The measuring instrument called a potentiometer is essentially a voltage divider used for measuring electric potential (voltage); the component is an implementation of the same principle, hence its name. Potentiometers are commonly used to control electrical devices such as volume controls on audio equipment. Potentiometers operated by a mechanism can be used as position transducers, for example, in a joystick. Potentiometers are rarely used to directly control significant power (more than a watt), since the power dissipated in the potentiometer would be comparable to the power in the controlled load.

3.2.1 Potentiometer construction Potentiometers consist of a resistive element, a sliding contact (wiper) that moves along the element, making good electrical contact with one part of it, electrical terminals at each end of the element, a mechanism that moves the wiper from one end to the other, and a housing containing the element and wiper.

Fig:3.2.1 Potentiometer construction Many inexpensive potentiometers are constructed with a resistive element (B) formed into an arc of a circle usually a little less than a full turn and a wiper (C) sliding on this element when rotated, making electrical contact. The resistive element can be flat or angled. Each end of the resistive element is connected to a terminal (E, G) on the case. The wiper is connected to a third terminal (F), usually between the other two. On panel potentiometers, the wiper is usually the center terminal of three. For single-turn potentiometers, this wiper typically travels just under one revolution around the contact. The only point of ingress for contamination is the narrow

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space between the shaft and the housing it rotates in. Another type is the linear slider potentiometer, which has a wiper which slides along a linear element instead of rotating. Contamination can potentially enter anywhere along the slot the slider moves in, making effective sealing more difficult and compromising long-term reliability. An advantage of the slider potentiometer is that the slider position gives a visual indication of its setting. While the setting of a rotary potentiometer can be seen by the position of a marking on the knob, an array of sliders can give a visual impression of, for example, the effect of a multi-band equalizer (hence the term "graphic equalizer"). The resistive element of inexpensive potentiometers is often made of graphite. Other materials used include resistance wire, carbon particles in plastic, and a ceramic/metal mixture called cermet. Conductive track potentiometers use conductive polymer resistor pastes that contain hard-wearing resins and polymers, solvents, and lubricant, in addition to the carbon that provides the conductive properties.

Fig:3.2.2 Types of potentiometer

Fig:3.2.3 Electronic symbol for potentiometer

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Others are enclosed within the equipment and are intended to be adjusted to calibrate equipment during manufacture or repair, and not otherwise touched. They are usually physically much smaller than user-accessible potentiometers, and may need to be operated by a screwdriver rather than having a knob. They are usually called "preset potentiometers" or "trim[ming] pots". Some presets are accessible by a small screwdriver poked through a hole in the case to allow servicing without dismantling. Multiturn potentiometers are also operated by rotating a shaft, but by several turns rather than less than a full turn. Some multiturn potentiometers have a linear resistive element with a sliding contact moved by a lead screw; others have a helical resistive element and a wiper that turns through 10, 20, or more complete revolutions, moving along the helix as it rotates. Multiturn potentiometers, both user-accessible and preset, allow finer adjustments; rotation through the same angle changes the setting by typically a tenth as much as for a simple rotary potentiometer. A string potentiometer is a multi-turn potentiometer operated by an attached reel of wire turning against a spring, enabling it to convert linear position to a variable resistance. User-accessible rotary potentiometers can be fitted with a switch which operates usually at the anti-clockwise extreme of rotation. Before digital electronics became the norm such a component was used to allow radio and television receivers and other equipment to be switched on at minimum volume with an audible click, then the volume increased, by turning a knob[24]. Multiple resistance elements can be ganged together with their sliding contacts on the same shaft, for example, in stereo audio amplifiers for volume control. In other applications, such as domestic light dimmers, the normal usage pattern is best satisfied if the potentiometer remains set at its current position, so the switch is operated by a push action, alternately on and off, by axial presses of the knob.

Fig:3.2.4 Circuit for potentiometer

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3.3 CAPACITORS: Devices which can store electronic charge are called capacitors. Capacitance can be understood as the ability of a dielectric to store electric charges. Its unit is Farad, named after the Michael Faraday. The capacitors are named according to the dielectric used. Most common ones are air, paper, and mica, ceramic and electrolytic capacitors. Physically a capacitor has conducting plates separated by an insulator or the dielectric. The plates of the capacitor have opposite charge, this gives rise to an electric field .In capacitor the electric field is concentrated in the dielectric between the plates. Like resistors, capacitors are also crucial to the correct working of nearly every electronic circuit and provide us with a means of storing electrical energy in the form of an electric field. Capacitors have numerous applications including storage capacitors in power supplies, coupling of A.C. signals between the stages of an amplifier, and decoupling power supply rails so that, As far as A.C. signal components are concerned, the supply rails are indistinguishable from zero volts.

TYPES OF CAPACITORS:

3.3.1 DISC CAPACITORS:

Fig 3.3.1 Disk Capacitors

In the disk form, silver is fired on to both sides of the ceramic to form the conductor plates. The sheets are then baked and cut to the appropriate shape and size & attached by pressure contact and soldering. These have high capacitance per unit volume and are very economical. The disks are lacquered or encapsulated in plastic or Phenolic molding. Round disk are used at high voltages the capacitance of values upto 0.01F can be obtained. They

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have tolerance of +20% or –20%. In general, these capacitors have voltage ratings up to 750 V D.C. 3.3.2ELECTROLYTIC CAPACITORS:

Fig 3.3.2 Electrolytic Capacitor These capacitors derive the name from electrolyte which is used as a medium to produce high dielectric constants. These capacitors have low value for large capacitances at low working voltages. There are two types ofElectrolytic capacitors: 

Aluminum Electrolytic capacitors.



Tantalum electrolytic capacitors

Electrolytic capacitors are used in circuits that have combination of D.C. voltage and A.C. The D.C. voltage maintains the polarity. They are used as ‘ripple filter’ where large capacitance is required at low cost in small space. They are also used as ‘biased capacitors’ and ‘decoupling capacitors’ and even as ‘coupling capacitors’ in R- C amplifier. 3.3.3COLOR CODING: Mica and tubular ceramic capacitors are color coded to indicate a capacitance value. As coding is necessary only for very small sizes, color coded capacitors value is also in the pF. The colors are the same as for the resistor coding from black for ‘0’ upto white for ‘9’. Mica capacitors use ‘six dot code system’.

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3.3.4 SIX DOT CODE: Here the top row is read from the left to right and the bottom from right to left .The dot indicates the following: (1) White(2) Digit (3) Digit (4) Multiplier (5) Tolerance (6) Class. White for the first dot indicates the coding. The capacitance value is read from the next three dots. If the first dot is silver it indicates paper capacitor. The white colored band indicates the left and specifies the temperature coefficient. The next three colors indicate the value of capacitance. For example, Brown, Black, Brown = 100 pF. 3.4DIODES:

Fig 3.4.1 Diodes To ensure unidirectional flow of liquid we use mechanical valves in its path. By properly arranging these valves in a system we get useful devices such as pumps and locomotives. In the field of electronics too we have a valve called semiconductor diode (a counterpart of thermionic valve) for controlling the flow of electric current in one direction. But we use these diodes in circuits for limited purposes like converting AC to DC, by passing EMF etc. a diode allows current to pass through it provided it is forward biased and the biasing voltage is more than potential barrier (forward voltage drop) of the diode.

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3.5TRANSISTOR:

Fig 3.5.1 Transistor The transistor an entirely new type of electronic device is capable of achieving amplification of weak signals in a fashion comparable and often superior to that realized by vacuum tubes. Transistors are far smaller than vacuum tube, have no filaments and hence need no heating power and may be operates in any position. They are mechanically strong, hence practically unlimited life and can do some jobs better than vacuum tubes. Invented in 1948 by J. Bardeen and W.H.Brattain of Bell Telephone Laboratories, a transistor has now become the heart of most electronic appliance. Though transistor is only slightly more the 45 years old, yet it is fast replacing vacuum tubes in almost all applications. A transistor consists of two pn junction formed by sand witching either p-type or ntype semiconductor between a pair of opposite type. Accordingly, there are two types of transistors namely: 

n-p-n transistor



p-n-p transistor An n-p-n is composed of two n-type semiconductors separated a by thin section of

p-type. However, a p-n-p is formed by two p-section separated by a thin section of n-type. 

These are two pn junctions. Therefore, a transistor may be regarded as a combination of two diodes connected back to back.



There are 3 terminals, taken from each type of semiconductor.

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

The middle section is very thin layer. This is the most important factor in the functioning of a transistor. Origin of the name “transistor “: When new devices are invented, scientists often try

to device a name that will appropriately describe the device. A transistor has two pn junctions. As the discussed later one junction is forward biased and the other is reversed biased. The forward biased junction has low resistance path whereas the reverse biased junction has low resistance path whereas the reverse biased junction has a high resistance path. The weak signal is introduced in the low resistance circuit and output is taken from the high resistance circuit. Therefore, a transistor transfers a signal from a low resistance to high resistance. The prefix ‘tans’ means the signal transfer property of the device while ‘istor’ classifies it as a solid element in the same general family with resistors. 3.5.1NAMING THE TRANSISTOR TERMINALS: A transistor (pnp or npn) has three sections of doped semiconductors. The section on one side is the emitter and the section on the opposite side is the collector. The middle section is called the base and forms two junctions between the emitter and collector. 

Emitter: - The section on one side that supplies charge carriers (electrons or holes) is called the emitter. The emitter is always forward biased w.r.t base so that it can supply a large number of majority carriers.



Collector: - The section on the other side that collects the charge is called the collector. The collector is always reversing biased. Its function is to remove charges from its junction with the base.



Base: - The middle section, which forms to pn junctions between the emitter and collector, is called base. The base emitter junction is forward biased, allowing low resistance for the emitter circuit. The base-collector junction is reversed biased and provides high resistance in the collector circuit.

3.5.2CHARACTERISTICS OF TRANSISTORS Whenever we have to decide about the applications of a transistor certain question arises. Some of these are – how much amplification gets from it? What is the highest

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frequency upto which it can be used? How much power output could we get from it? And what should be the values of different components used in the circuits? The answers to these entire questions lie in the electrical properties of the transistor. These properties depend on the size, manufacturing techniques and materials used in the manufacturer of transistor and are know as characteristics. Transistor manufacturers give these characteristics in the data sheets published by them. 

Current gain factor ‘alpha’

()



Current gain factor ‘beta’

()



Input resistance

(Rin)



Output resistance

(Rout)



Cut-off frequency

(F  and F)



Leakage current

(I ‘co)



Maximum permissible limits:

1.

Maximum collector voltage

(Vceo)

2.

Maximum emitter current

(IC Max)

3.

Maximum Power dissipation

(P max)

3.6RELAY:

Fig 3.6.1 Relay A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. Relays are used where it is necessary to control a circuit by a low-power signal (with complete electrical isolation between control and controlled circuits), or where several

59

circuits must be controlled by one signal. The first relays were used in long distance telegraph circuits, repeating the signal coming in from one circuit and re-transmitting it to another. Relays were used extensively in telephone exchanges and early computers to perform logical operations. A type of relay that can handle the high power required to directly drive an electric motor is called a contactor. Solid-state relays control power circuits with no moving parts, instead using a semiconductor device to perform switching. Relays with calibrated operating characteristics and sometimes multiple operating coils are used to protect electrical circuits from overload or faults; in modern electric power systems these functions are performed by digital instruments still called “protective relays”. 3.6.1BASIC DESIGN AND OPERATION: A simple electromagnetic relay consists of a coil of wire surrounding a soft iron core, an iron yoke which provides a low reluctance path for magnetic flux, a movable iron armature, and one or more sets of contacts (there are two in the relay pictured). The armature is hinged to the yoke and mechanically linked to one or more sets of moving contacts. It is held in place by a spring so that when the relay is de-energized there is an air gap in the magnetic circuit. In this condition, one of the two sets of contacts in the relay pictured is closed, and the other set is open. Other relays may have more or fewer sets of contacts depending on their function. The relay in the picture also has a wire connecting the armature to the yoke. This ensures continuity of the circuit between the Moving contacts on the armature, and the circuit track on the printed circuit board (PCB) via the yoke, which is soldered to the PCB. When an electric current is passed through the coil it generates a magnetic field that attracts the armature, and the consequent movement of the movable contact(s) either makes or breaks (depending upon construction) a connection with a fixed contact. If the set of contacts was closed when the relay was de-energized, then the movement opens the contacts and breaks the connection, and vice versa if the contacts were open. When the current to the coil is switched off, the armature is returned by a force, approximately half as strong as the magnetic force, to its relaxed position. Usually this force is provided by a spring, but gravity is also used commonly in industrial motor starters. Most relays are manufactured to operate quickly. In a low-voltage application this reduces noise; in a high 60

voltage or current application it reduces arcing. When the coil is energized with direct current, a diode is often placed across the coil to dissipate the energy from the collapsing magnetic field at deactivation, which would otherwise generate a voltage spike dangerous to semiconductor circuit components. Some automotive relays include a diode inside the relay case. Alternatively, a contact protection network consisting of a capacitor and resistor in series (snubber circuit) may absorb the surge. If the coil is designed to be energized with alternating current (AC), a small copper “shading ring” can be crimped to the end of the solenoid, creating a small out-of-phase current which increases the minimum pull on the armature during the AC cycle. A solid-state relay uses a thyristor or other solid-state switching device, activated by the control signal, to switch the controlled load, instead of a solenoid. An optocoupler (a lightemitting diode (LED) coupled with a photo transistor) can be used to isolate control and controlled circuits.

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Chapter 4 PCB DESIGNING & SOLDERING TECHNIQUES

4.1: PCB DESIGNING:

Fig 4.1.1 Fig PCB Designing 1. Design your circuit board. Use PCB computer-aided design (CAD) software to draw your circuit board. You can also use a perforated board that has pre-drilled holes in it to help you see how your circuit board's components would be placed and work in reality. 2. Buy a plain board that is coated with a fine layer of copper on one side from a retailer. 3. Scrub the board with a scouring pad and water to make sure the copper is clean. Let the board dry. 4. Print your circuit board's design onto the dull side of a sheet of blue transfer paper. Make sure the design is oriented correctly for transfer. 5. Place the blue transfer paper on the board with the circuit board's printed design against the copper. 6. Lay a sheet of ordinary white paper over the blue paper. Following the transfer paper's 62

instructions, iron over the white and blue paper to transfer the design onto the copper board. Iron every design detail that appears near an edge or corner of the board with the tip of the iron. 7. Let the board and blue paper cool. Peel the blue paper slowly away from the board to see the transferred design. 8. Examine the transfer paper to check for any black toner from the printed design that failed to transfer to the copper board. Make sure the board's design is oriented correctly. 9. Replace any missing toner on the board with ink from a black permanent marker. Allow the ink to dry for a few hours. 10. Remove exposed parts of the copper from the board using ferric chloride in a process called etching. 11. Put on old clothes, gloves and safety goggles. 12. Warm the ferric chloride stored in a non-corrosive jar and sealed with a non-corrosive lid, in a bucket of warm water. Do not heat it above 115 F (46 C) to prevent toxic fumes from being released. 13. Pour only enough ferric chloride to fill a plastic tray that has plastic risers in it to rest the circuit board on. Be sure to do this in a well-ventilated space. 14. Use plastic tongs to lay the circuit board face down on the risers in the tray. Allow 5 to 20 minutes, depending on the size of your circuit board, for the exposed copper to drop off the board as it etches away. Use the plastic tongs to agitate the board and tray to allow for faster etching if necessary. 15. Wash all the etching equipment and the circuit board thoroughly with plenty of running water. 16. Drill 0.03-inch (0.8 mm) lead component holes into your circuit board with high-speed steel or carbide drill bits. Wear safety goggles and a protective mask to protect your eyes and lungs while you drill. 17. Scrub the board clean with a scouring pad and running water. Add your board's electrical components and solder them into place.

4.2: SOLDERING TECHNIQUES Soldering is the only permanent way to ‘fix’ components to a circuit. However, soldering requires a lot of practice as it is easy to ‘destroy’ many hours preparation and design work by

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poor soldering. If you follow the guidelines below you have a good chance of success

Fig 4.2.1 Soldering Iron Use a soldering iron in good condition. Inspect the tip to make sure that it is not past good operation. If it looks in bad condition it will not help you solder a good joint. The shape of the tip may vary from one soldering iron to the next but generally they should look clean and not burnt.

Fig 4.2.2 PCB Erasing A PCB eraser is used to remove any film from the tracks. This must be done carefully because the film will prevent good soldering of the components to the PCB. The track can be checked using a magnified glass. If there are gaps in the tracks, sometimes they can be repaired using wire but usually a new PCB has to be etched.

Fig 4.2.3 Soldering

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The heated soldering iron should then be placed in contact with the track and the component and allowed to heat them up. Once they are heated the solder can be applied. The solder should flow through and around the component and the track. Having completed soldering the circuit the extended legs on the components need to be trimmed using wire clippers. The circuit is now ready for testing.

Fig 4.2.4 Extended Leg Trimming

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Chapter 5 FLOW CHART 5.1 FLOW CHART:

Fig 5.1.1 Flow Chart of System Before Ignition

66

Fig 5.1.2 Flow Chart of System After Ignition

67

Chapter 6 RESULTS AND DISCUSSION 6.1 INTRODUCTION Snapshots of the test results are shown to get a better idea of the desired output. This chapter deals with the design testing and simulation results.

6.2 SIMULATION AND TEST RESULTS The below figure shows the initial setup when power is switched on

Fig: 6.2.1 Initial setup when power is ON

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If the rider didn’t wear the helmet, then following message will be displayed and the engine remains turned OFF.

Fig. 6.2.2 Confirmation of wearing helmet

If the rider is drunk and riding then the following message will be displayed and engine of the bike remains turned OFF.

Fig 6.2.3 Alcohol Detection If accident occurs then vibration sensor will detects accident and message will sent to the registered numbers.

Fig. 6.2.4 Accident Detection

Chapter 7 69

ADVANTAGES AND LIMITATIONS 7.1 Introduction: The main advantages and limitations of the Smart Helmet are discussed below.

7.2 Advantages: 1. It will help to reduce the number of road accidents which are very frequent in a country like India where the traffic is very high. 2. It will help to create awareness about the need to wear helmet during bike riding. 3. The system will ensure that the motorbike will not start unless the rider is wearing a helmet and has not consumed alcohol. 4. Also GSM technology is used to inform the family members in case of an accident.

7.3 Limitations: 1.The bike will not start unless we wear the helmet. 2.Miss handling of the helmet may cause unnecessarily message alert.

Chapter 8

70

CONCLUSION AND FUTURE SCOPE 8.1 Introduction: The main aim of this project is to encourage people to wear helmet and to prevent road accidents, which is achieved. Thus, road accidents can be prevented to some extent and safety of bike riders is ensured.

8.2 Conclusion: The designed system is highly useful to avoid accidents which happen around the nighttime. It provides more than 70% safety for two wheelers. It is the fact that implementation of system will increase cost of vehicle, but it is better to have some percent safety rather than having no percent of safety.

8.3 Future Scope: This system could be further enhanced with future technologies to provide further more safety and security to the vehicle systems, such as sensing the obstacles or static objects in front of the vehicles so the accidents due to static obstacles could be avoided. The system has been designed for a special objective that should protect not only the person riding the vehicle but also the persons around it like pedestrians and also to prevent collision of vehicles with the other vehicle or obstacles such as trees.

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REFERENCES [1]

SMART

HELMET

FOR

TWO-WHEELERS

by

Ravi

Nandu

and

Kuldeep

Singh,SRMUniversity, Department of Automobile Engineering, Kattankulathur, Chennai603203, India. [2] DESIGN OF ACCURATE NAVIGATION SYSTEM BY INTEGRATING INS ANDGPSUSING EXTENDED KALMAN FILTER by Santhosh Kumar, MS. Suganthi Assistantprofessor, Department of TEC, PES institute of technology, Bangalore, Karnataka. [3] SMART HELMET by Mr. Vivek A. Patel1, Mr. Akash Mishra2, Mr. Rana Hiten3, Mr.Kautik Prajapati4 1Assistant professor, electrical Eng., Mahavir Swami College of Eng. &Tec, Surat, Gujarat, India 2, 3, 4 Student, electrical Eng., Mahavir Swami College of Eng. &Tec, Surat, Gujarat, India. [4]

Smart

Helmet

Using

GSM

&GPS

Technology

for

Accident

Detection

and

ReportingSystemInternational Journal of Electrical and Electronics Research Month: October – December2014 byManjesh N M Tech, ECE-DSCE, JNTUA, Hindupur, India Prof. Sudarshan Raj.HOD & Asst. Prof. BIT-IT, Hindupur, India. [5] Smart with sensors for accident detection by Mohd Khairul Afiq Mohd Rasli; NinaKorlinaMadzhi; Juliana Johari. [6] A Low and Intelligent Helmet By Ratul Kumar Baruah Albert Daimary; MeghnaGoswami. [7] An Internet of Things (IoT) based smart helmet for accident detection and notificationBy Sreenithy

Chandran

;

Sneha

ElectronicsandCommunication

Chandrasekar

Engineering

Sri

;

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Edna

Elizabeth

Sivasubramaniya

Department

Nadar

College

of of

EngineeringKalavakkam, India. [8] Intelligent transportation system for accident prevention and detection by D. Selvathi; P.Pavithra ; T. Preethi Department of ECE Mepco Schlenk Engineering College Sivakasi,Tamilnadu, India. [9] SAFETY AND ALERTING SYSTEM OF VEHICLES USING A SMART HELMET by JERLINJOSE S. T, RAHUL A. S., SAJIN S. * Department of Electronics and CommunicationEngineering,Bethlahem Institute of Engineering, Karungal, Tamil Nadu, India. [10] International Journal of Scientific & Engineering Research Volume 2, Issue 12, December2011 ISSN 2229-5518 IJSER. [11] International Journal of Science and Research (IJSR)ISSN (Online): 2319‐7064. [12]“Vehicle Accident Alert & Locator” IJECS-IJENS Volume 11, Issue 02.

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[13]www.academia.edu/6541133/Smart_Helmet.php [14] I(IJSR) ISSN(Online):2319‐7064 Vijay J, Saritha B,Priyadharshini B, Deepeka S andLaxmiR(2011),“Drunken Drive Protection System”, International Journal of Scientific &Engineering Research,Vol.2,No.12,ISSN:2229-5518. [15]https://www.electrical4u.com/working-or-operating-principle-of-dc-motor [16]http://www.rakeshmondal.info/L293D-Motor-Driver [17]http://www.circuitstoday.com/how-a-led-works-light-emitting-diode-working [18]http://sensorworkshop.blogspot.in/2008/04/sensor-report-mq3-gas-sensor.html [19]http://www.futurlec.com/Alcohol_Sensor.shtml [20]http://www.espruino.com/datasheets/SIM900_AT.pdf [21]https://learn.sparkfun.com/tutorials/gps-basics [22]http://gpsworld.com/what-exactly-is-gps-nmea-data/

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