RAILWAY TRACK SECURITY SYSTEM USING ARDUINO
A Project report submitted to
Jawaharlal Nehru Technological University Kakinada, Kakinada
Bachelor of Technology
In
Electronics and Communication Engineering
Submitted By
C.VANITHA
(16X91A0414)
D. GURU MOUNIKA
(16X91A0418)
G.RAJA REDDY
(16X91A0423)
G.PRASAD
(16X91A0422)
Under the esteemed guidance of
Mr.K.SUNEEL BABU,M.Tech.,
Assistant Professor.
DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING
SRI SATYANARAYANA ENGINEERING COLLEGE::ONGOLE
(An ISO 9001:2008 Certified Institution)
(Approved by AICTE,New Delhi& Affiliated to J.N.T.University,KAKINADA)
Ongole-523225.,A.P
2016-2020.
SRI SATYANARAYANA ENGINEERING COLLEGE::ONGOLE
(An ISO 9001:2008 Certified Institution)
(Approved by AICTE,New Delhi& Affiliated to J.N.T.University,KAKINADA)
Ongole-523225,A.P.
DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING
CERTIFICATE
This is to certify that the main project report titled “ RAILWAY
TRACK SECURITY SYSTEM USING ARDUINO” is the bonafied
work carried out by
C.VANITHA
(16X91A0414)
D. GURU MOUNIKA
(16X91A0418)
G.RAJA REDDY
(16X91A0423)
G.PRASAD
(16X91A0422)
in partial fulfillment of the requirements for the award of Bachelor of
Technology in Electronics and Communication Engineering by J.N.T.U.K,
Kakinada during the academic year2019-2020.
Project Guide
Mr.K.SUNEEL BABU
M.Tech.,
ASSISTANT PROFESSOR.
Project Co-ordinator
Mr.R.KOTESWARA RAO
M.Tech.,
ASSOCIATE PROFESSOR.
EXTERNAL EXAMINER.
H.O.D
Mr.D.JAYA NAYUDU
M.E.,(PhD).,
PROFESSOR.
ACKNOWLEDGEMENT
We would like to express our profound sense of gratitude and indebtedness to our project guide Mr.K.SUNEEL
BABU M.Tech., Assistant professor of ECE department, SSN Engineering College, Ongole for the valuable guidance
and inspiration rendered by him during this project work. Mere words would not be sufficient to place on record the
erudite guidance, sustained encouragement constructive comments and inspiring discussions with him during course of
this project work.
We honorably express our thanks to our project coordinator sri R.KOTESWARA RAO M.Tech., Associate
professor for providing us an atmost congenial atmosphere to carry out our work peacefully.
We are highly grateful and indebted to Mr.D.JAYA NAYUDU M.E.,(PhD)., professor and Head of the
Department of ECE, SSN Engineering College, Ongole for his support and valuable suggestions for completing this
project.
We would like to express our deep sense of gratitude to all staff members of Electronics and Communication
Engineering Department, SSN Engineering College, Ongole for their support in various aspects in completing this project.
We would like to place on record the valuable academic support given by our principal Sri Dr.C.VEERESH
NAYAK M.Tech.,PhD., for completion of the course .
We would like to place on record the deep sense of gratitude to sense of gratitude to Sri.Y.SATYA
NARAYANA REDDY garu,Director, SSN group of institutions for providing necessary facilities to carry the concluded
project work.
We express our sincere gratitude and thanks to our honorable Secretary and Correspondent Sri.
Y.RAMAKRISHNA REDDY garu, for providing us with good faculty and infrastructure and for his moral support
throughout the course.
We would like to convey gratitude to our parents whose prayers and blessings are always with us.
In this regard we would like to thank my friends and others who helped us directly or indirectly for successful
completion of the seminar presentation.
C.VANITHA
(16X91A0414)
D.GURU MOUNIKA
(16X91A0418)
G.RAJA REDDY
(16X91A0423)
G.PRASAD
(16X91A0422)
i
ABSTRACT
Indian railways are one of the largest railway networks of the world.
Despite the huge size, the rampant negligence and lack of maintenance have created a
number of problems. The main problem being that, frequent cracks are found in the rail
lines which cause derailments leading to huge loss of life and property. In fact, the year
2010 alone, reports around 21 train crashes leading to around 450 deaths. Having
researched about the conventional methods of railway track detection includes
ultrasonic and eddy current based approaches, we find that their expensive nature does
not warrant their use in the current scenario.
Hence, we aim to create a new LED-LDR based simple technique to detect
cracks in rails that will be cheap enough, so that it can be put to mass usage. Our
scheme consists of a railway line looking for cracks during night time when local
railways don’t operate. This project will be powered by a DC to motor traverse the
railway line. It will be equipped with a LED (Light Dependent Resistor) and LDR
arrangement. When a crack is present in the railway line the light falls on the LDR and
its resistance decreases. This is detected by a microcontroller which then turns ON
buzzer. Then micro controller will track the location of crack then it will display the
location on LCD as well as it will send the location values by using GSM. To indicate
the exact fault location.
ii
INDEX
CONTENTS
PAGE NO.
ACKNOWLEDGEMENT
i
ABSTRACT
ii
LIST OF FIGURES
v
LIST OF TABLES
vii
CHAPTER-1:INTRODUCTION
1.1 Overview
1
1.2 Literature survey
2
1.3 Problem Identification
3
1.4 Advantages
3
1.5 Applications
4
1.6 Outline of thesis
4
CHAPTER-2:EMBEDDED SYSYTEM
2.1 What is Embedded System
5
2.2 Need for Embedded System
6
2.3 Application Areas
7
CHAPTER-3:IMPLEMENTATION OF RAILWAY TRACK
FAULT DETECTION SYSTEM
3.1 Block diagram
8
3.2 INPUTS
8
3.2.1 LED
8
3.2.2 LDR
15
3.2.3 GPS
19
3.3 Technology
27
3.3.1 Arduino
27
3.3.2 At,mega 328
3.4 OUTPUTS
32
37
3.4.2 LCD Module
37
3.4.3 GSM
39
3.5 POWER SUPPLY
42
3.5.1 Step down Transformer
44
3.5.2 Bridge Rectifier
44
3.5.3 Filter
46
3.5.4 Voltage regulator
49
3.6 Software and Hardware Tools
51
3.7 Working Principle
51
3.8 Flow Chart
52
CHAPTER-4:SOFTWARE USAGE
4.1 Arduino IDE
53
CHAPTER-5:RESULT ANALYSIS
56
FUTURE SCOPE
57
CONCLUSION
58
REFERENCES
59
APPENDIX-A:SOFTWARE CODING
60
LIST OF FIGURE
Figure no.
Title
Page no.
3.1
Block diagram
8
3.2
Light Emitting Diode
9
3.3
P-N Junction
3.4
V-I Characteristics of LED
3.5
Circuit symbol of LDR
16
3.6
Working principle of LDR
17
3.7
Variation of LDR Resistance with
10
11
Variation in light Intensity
17
3.8
Light Intensity vs LDR Resistance
18
3.9
Light Dependent Resistor Circuit
19
3.10
GPS Satellite System
20
3.11
Arduino Board
28
3.12
Pin diagram
33
3.13
Buzzer
37
3.14
Circuit diagram for Buzzer
3.15
2*16 line Alphanumeric LCD Display
3.16
GSM Module
42
3.17
Power supply diagram
44
3.18
Step down Transformer
45
3.19
Half wave Rectifier
46
3.20
Full wave Rectifier
47
V
38
40
3.21
Bridge Rectifier
48
3.22
7805 voltage Rectifier
50
4.1
Arduino 1.8.0 window
53
4.2
Arduino 1.8.0 uploading blink window
5.1
Output picture of railway track fault
Detection system
54
56
VI
LIST OF TABLES
Table no.
Title
Page no.
3.1
Colours and Wave lengths
12
3.2
Pin Description of Arduino
28
3.3
Arduino uno Technical specifications
3.4
Key parameters of Atmega 328
33
3.5
Pin Description of Atmega 328
35
3.6
Pin Details of 7805 IC
VII
31
51
RAILWAY TRACK SECURITY SYSTEM
CHAPTER 1
INTRODUCTION
1.1 OVERVIEW
In today’s world, transport is a key necessity because in its absence it would be
impossible for products to be consumed in areas which are not in the immediate vicinity of the
production centres. Throughout history, transport has been a necessity for the expansion of trade.
Economic prosperity can be achieved by increasing the rationality and capacity of transport
systems. The proper operation and maintenance of transport infrastructure has a great impact on
the economy. Transport, being one of the biggest drainers of energy, its sustainability and safety
are issues of paramount importance. In all over world, rail transport occupies a prominent
position in quenching the ever- burgeoning needs of a rapidly growing economy. However, in
terms of the reliability and safety parameters, global standards have not yet been truly reached.
For example in the Indian railway network, today has track length of 113,617 kilometres
(70,598 mi). Over a route of 63,974 kilometres (39,752 mi) and 7,083 stations. It is the fourth
largest railway network in the world exceeded only by those of the United States, Russia and
China. The rail network traverses every length and breadth of India and is known carry over 30
million passengers and 2.8 million tons of freight daily.
Though rail transport here is growing at a rapid pace, the associated safety infrastructure
facilities have not kept up with the aforementioned proliferation. Here facilities are inadequate
compared to the international standards and as a result, there have been frequent derailments that
have resulted in severe loss of valuable human lives and property as well. To demonstrate the
gravity of the problem, official statistics say that there have been 11 accidents in 2011 till the
month of July alone, which leaves much to be desired. On further analysis of the factors that
cause these rail accidents, recent statistics reveal that approximately 60% of all the rail accidents
have derailments as their cause, of which about 90% are due to cracks on the rails either due to
natural causes (like excessive expansion due to heat) or due to antisocial elements. Hence these
cracks in railway lines have been a perennial problem, which has to be addressed with utmost
attention due to the frequency of rail usages.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 1
RAILWAY TRACK SECURITY SYSTEM
These cracks and other problems with the rails generally go unnoticed due to improper
maintenance and the currently irregular and manual track line monitoring that is being carried
out. The high frequency of trains and the unreliability of manual labour have put forth a need for
an automated system to monitor the presence of crack on the railway lines being carried out. The
high frequency of trains and the unreliability of manual labour have put forth a need for an
automated system to monitor the presence of crack on the railway lines.
The problem inherent in all these techniques is that the cost incurred is high. Hence this
paper proposes to the a cheap, novel yet simple scheme with sufficient ruggedness suitable to the
all over world that uses an LED-LDR arrangement to detect the crack in railway lines, which
proves to be cost effective as compared to the existing methods. The important role played by
transport in the development of an economy has been studied. In addition, statistics of the
number of rail accidents and their corresponding causes have also been studied.
1.2 LITERATURE SURVEY
Recently research and development of rail track inspection have received a great deal of
attention to save passengers life. The prompt detection of the condition in rails that may lead to
crack or rather a break now plays a critical role in the maintenance of rail. The project
specification of implementation result of RCDS used simple components inclusive of crack
detector IR LED-PHOTODIODE based setup.
To design crack inspection system and utilized for low cost feature robot which is on
embedded platform for finding the cracks. The obstacles and cracks are detected by utilizing
sensors in the robot, which are then apprized to the train driver through the GSM utilizing radio
frequency signals.
Firstly, we had a survey of existing technologies of automatic track security. This survey
helped us to understand which technologies are suitable for our system which will make more
efficient and easy to use. From all the developed or established system worked only one or two
parts of the whole system. Here, we give a short review of the technologies which are already
developed.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 2
RAILWAY TRACK SECURITY SYSTEM
1.3 PROBLEM IDENTIFICATION :
Collision is one of the major issues of train accidents in every country. To make an anticollision system, author provide a system by LED and LCD panel to find if two trains are in
same track or different track This technology will identify the collision points and also send the
distance of two train to the control room. It will monitor the system to slow down the speeds of
trains. Obstacle detection is another important part of railway security system. For detecting
obstacle system need to sense train arrival so author used vibration sensor. To sense the obstacle
in the path of trains obstacle sensor is used and send signal to microcontroller. Author divided
the rails into several blocks and all blocks consisted of laser sensors and microcontroller. The
laser sensor mainly sends signal to train either to stop or continue to run.
Vision based method is used for automatic railroad track inspection. In this system,
camera plays a vital role to capture and collect the images and videos. Author used image
processing and MUSIC algorithm in this system. Image processing helped to process the frame
image and MUSIC algorithm helped to detect number of signal in the presence of noise.
Railway track security is the prime concern of our project. We think if we can give
proper security to the railway tracks, it will be so helpful for the transportation system of our
country and this will also help a lot in the economic development of our country.
GPS (Global Positioning System) to enable autonomous and reliable determination of the
train position, to the velocity under practically all environmental conditions. Another
ethnological approach for the train location function: the use of GNSS signals integrated with
inertial sensors.
1.4 ADVANTAGES
 Create an intelligent on target tracking.
 Wireless monitoring and control system.
 Its cost very low compared to existing system.
 Very accurate detection.
 Transmitting signals are immediately transfer.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 3
RAILWAY TRACK SECURITY SYSTEM
 It also checks surface and near surface of the cracking position.
 Accidents reduced.
1.5 APPLICATIONS
 Railway track damage detection application.
 Wireless applications.
 Industrial and access control.
 Navy applications.
1.6 OUTLINE OF THESIS
We would like to give a brief report about “ RAILWAY TRACK SECURITY
SYSTEM USING ARDUINO ”.
Chapter 1:
Describes the introduction about our project. Here we explained about introduction, advantages
and applications of this project.
Chapter 2:
Deals with the introduction of Embedded Systems. Here we explained about what is embedded
systems, .need for embedded systems and its applications
Chapter 3:
Describes the total description of the block diagram. In this chapter all the blocks in the block
diagram are explained.
Chapter 4:
Describes the ARDUINO IDE software.
Chapter 5:
Describes the circuit diagram and physical appearance of RAILWAY TRACK SECURITY
SYSTEM USING ARDUINO.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 4
RAILWAY TRACK SECURITY SYSTEM
CHAPTER-2
EMBEDDED SYSTEM
2.1 WHAT IS EMBEDDED SYSTEM
An Embedded System is a combination of computer hardware and software, and perhaps
additional mechanical or other parts, designed to perform a specific function. A good example is
the microwave oven. Almost every household has one, and tens of millions of them are used
every day, but very few people realize that a processor and software are involved in the
preparation of their lunch or dinner.
This is in direct contrast to the personal computer in the family room. It too is comprised
of computer hardware and software and mechanical components (disk drives, for example).
However, a personal computer is not designed to perform a specific function rather; it is able to
do many different things. Many people use the term general-purpose computer to make this
distinction clear. As shipped, a general-purpose computer is a blank slate; the manufacturer does
not know what the customer will do wish it. One customer may use it for a network file server
another may use it exclusively for playing games, and a third may use it to write the next great
American novel.
Frequently, an embedded system is a component within some larger system. For
example, modern cars and trucks contain many embedded systems. One embedded system
controls the anti-lock brakes, other monitors and controls the vehicle's to the of
emissions, and a third displays information on the dashboard. In some cases, these embedded
systems are connected by some sort of a communication network, but that is certainly not a
requirement.
At the possible risk of confusing you, it is important to point out that a general-purpose
computer is itself made up of numerous embedded systems. For example, my computer consists
of a keyboard, mouse, video card, modem, hard drive, floppy drive, and sound card-each of
which is an embedded system. Each of these devices contains a processor and software and is
designed to perform a specific function.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 5
RAILWAY TRACK SECURITY SYSTEM
For example, the modem is designed to send and receive digital data over analog
telephone line. That's it and all of the other devices can be summarized in a single sentence as
well.
If an embedded system is designed well, the existence of the processor and software
could be completely unnoticed by the user of the device. Such is the case for a microwave oven,
VCR, or alarm clock. In some cases, it would even be possible to build an equivalent device that
does not contain the processor and software. This could be done by replacing the combination
with a custom integrated circuit that performs the same functions in hardware. However, a lot of
flexibility is lost when a design is hard-cooled in this way. It is must easier, and cheaper, to
change a few lines of software than to redesign a piece of custom hardware.
An embedded system is a computer system designed to perform one or a few dedicated
functions often with real-time computing constraints. It is embedded as part of a complete
device often including hardware and mechanical parts. By contrast, a general-purpose computer,
such as a personal computer (PC), is designed to be flexible and to meet a wide range of enduser needs. Embedded systems control many devices in common use today.
Embedded systems are controlled by one or more main processing cores that are typically
either the of microcontrollers or digital signal processors (DSP). The key characteristic, however,
is being dedicated to handle a particular task, which may require very powerful processors. Since
the embedded system is dedicated to specific tasks, design engineers can optimize it to reduce
the size and cost of the product and increase the reliability and performance. Some embedded
systems are mass-produced, benefiting from economies of scale.
2.2 Need For Embedded System :
The uses of embedded systems are virtually limitless, because every day new products
are introduced to the market that utilizes embedded computers in novel ways. In recent years,
hardware such as microprocessors, microcontrollers, and FPGA chips have become much
cheaper. So when implementing a new form of control, it's wiser to just buy the generic chip
and write your own custom software for it. Producing a custom-made chip to handle a particular
task or set of tasks costs far more time and money. Many embedded computers even come with
extensive libraries, so that "writing your own software" becomes a very trivial task indeed.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 6
RAILWAY TRACK SECURITY SYSTEM
2.3 APPLICATION AREAS
Nearly 99 percent of the processors manufactured end up in embedded systems. The
embedded system market is one of the highest growth areas as these systems are used in very
Market segment consumer electronics, office automation, indrustrial automation, bio medical
engineering, wireless communication, data communication, tele communication., transportation,
military and so on.
Automation Systems :
In modern era, we all are aware of Automation systems. Whether you are at home or
your office, if things are not automated then it can make your work quite difficult. We don’t
need to go far, let’s take the example of remote control. It has made our life so easy now we can
turn things on or off by simply clicking buttons on our remote control. Smart Home automation
is a widely diverse application of embedded systems.
Security Systems :
Now coming towards security systems, these are all the fruits of embedded systems.
These days we have sensors installed in our homes and even if you are not at home you can still
get complete visuals camera feeds on your mobile from anywhere in the world. That became
possible just because of Embedded Systems.
APPLIANCES :
Most of our home appliances, like kitchen appliances which we normally called
electric products are actually embedded products, micro Ovens, Toasters, burners.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 7
RAILWAY TRACK SECURITY SYSTEM
CHAPTER 3
IMPLEMENTATION OF RAILWAY TRACK FAULT
DETECTION SYSTEM
3.1 BLOCK DIAGRAM
LED 2
LDR 2
A
LCD
R
D
U
LED 1
LDR 1
BUZZER
I
N
O
GSM
GPS
Fig.3.1: Block Diagram
3.2 Inputs
3.2.1 LED (Light Emitting Diode)
A light-emitting diode (LED)is a two-lead semiconductor light source. It is a p-n
junction diode that emits light when activated. When a suitable current is applied to the leads,
electrons are able to recombine with electron holes within the device, releasing energy in the
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 8
RAILWAY TRACK SECURITY SYSTEM
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 band gap of the
semiconductor. LEDs are typically small (less than 1 mm2) and integrated optical components
may be used to shape the radiation pattern.
Appearing as practical electronic components in 1962, the earliest LEDs emitted lowintensity infrared light. Infrared LEDs are still frequently used as transmitting elements in
remote-control circuits, such as those in remote controls for a wide variety of consumer
electronics. The first visible-light LEDs were of low intensity and limited to red. Modern LEDs
are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness.
Fig.3.2: Light Emitting Diode
Early LEDs were often used as indicator lamps for electronic devices, replacing small
incandescent bulbs. They were soon packaged into numeric readouts in the form of sevensegment displays and were commonly seen in digital clocks. Recent developments have
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 9
RAILWAY TRACK SECURITY SYSTEM
produced LEDs suitable for environmental and task lighting. LEDs have led to new displays and
sensors, while their high switching rates are useful in advanced communications technology.
LEDs have many advantages over incandescent light sources, including lower energy
consumption, longer lifetime, improved physical robustness, smaller size, and faster switching.
Light-emitting diodes are used in applications as diverse as aviation lighting, automotive
headlamps, advertising, general lighting, traffic signals, camera flashes, lighted wallpaper and
medical devices. They are also significantly more energy efficient and, arguably, have fewer
environmental concerns linked to their disposal.
Unlike a laser, the color of light emitted from an LED is neither coherent nor
monochromatic, but the spectrum is narrow with respect to human vision, and for most purposes
the light from a simple diode element can be regarded as functionally monochromatic.
 Working Principle
Fig.3.3: P-N junction
The electrons dissipate energy in the form of heat for silicon and germanium diodes. A
P-N junction can convert absorbed light energy into a proportional electric current. The same
process is reversed here (i.e. the P-N junction emits light when electrical energy is applied to it).
This phenomenon is generally called electroluminescence, which can be defined as the
emission of light from a semiconductor under the influence of an electric field. The charge
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 10
RAILWAY TRACK SECURITY SYSTEM
carriers recombine in a forward-biased P-N junction as the electrons cross from the N-region
and recombine with the holes existing in the P-region. Free electrons are in the conduction
band of energy levels, while holes are in the valence energy band.
Thus the energy level of the holes is less than the energy levels of the electrons. Some
portion of the energy must be dissipated to recombine the electrons and the holes. This energy is
emitted in the form of heat and light. But in gallium arsenide phosphate (GaAsP) and gallium
phosphate (Gap) semiconductors, the electrons dissipate energy by emitting photon. If the
semiconductor is translucent, the junction becomes the source of light as it is emitted, thus
becoming a light-emitting diode. However, when the junction is reverse biased, the LED
produces no light and—if the potential is great enough, the device is damaged.
Fig.3.4: V-I characteristics of LED
The wavelength of the light emitted, and thus its color, depends on the band gap energy
of the materials forming the p-n junction. In silicon or germanium diodes, the electrons and holes
usually recombine by a non-radioactive transition, which produces no optical emission, because
these are indirect band gap materials. The materials used for the LED have a direct band
gap with energies corresponding to near-infrared, visible, or near-ultraviolet light.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 11
RAILWAY TRACK SECURITY SYSTEM
LED development began with infrared and red devices made with gallium arsenide.
Advances in materials science have enabled making devices with ever-shorter wavelengths,
emitting light in a variety of colors.
LEDs are usually built on an n-type substrate, with an electrode attached to the p-type
layer deposited on its surface. P-type substrates, while less common, occur as well. Many
commercial LEDs, especially GaN/InGaN, also use sapphire substrate. Efficiency and
operational parameters
Typical indicator LEDs are designed to operate with no more than 30–60 mill
watts (mW) of electrical power. Around 1999, Philips limitless introduced power LEDs capable
of continuous use at one watt. These LEDs used much larger semiconductor die sizes to handle
the large power inputs. Also, the semiconductor dies were mounted onto metal slugs to allow
for greater heat dissipation from the LED die.
One of the key advantages of LED-based lighting sources is high luminous efficacy.
White LEDs quickly matched and overtook the efficacy of standard incandescent lighting
systems. In 2002, Lucile’s made five-watt LEDs available with luminous efficacy of 18–22
lumens per watt (lm/W). For comparison, a conventional incandescent light bulb of 60–100
watts emits around 15 lm/W, and standard fluorescent lights emit up to 100 lm/W.
As of 2012, Philips had achieved the following efficacies for each color. The efficiency
values show the physics – light power out per electrical power in. The lumen-per-watt efficacy
value includes characteristics of the human eye and is derived using the luminosity function.
Table No.3.1: Colors and Wavelengths
Colour
Red
Wavelength
Typical
range
efficiency
(nm)
Coefficient
620 < λ < 645
Typical efficacy
(lm/w)
0.39
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
72
Page 12
RAILWAY TRACK SECURITY SYSTEM
Red-orange
610 < λ < 620
0.29
98
Green
520 < λ < 550
0.15
93
Cyan
490 < λ < 520
0.26
75
Blue
460 < λ < 490
0.35
37
In September 2003, a new type of blue LED was demonstrated by Cree. This produced a
commercially packaged white light giving 65 lm/W at 20 mA, becoming the brightest white
LED commercially available at the time, and more than four times as efficient as standard
incandescent. In 2006, they demonstrated a prototype with a record white LED luminous
efficacy of 131 lm/W at 20 mA.
Nichia Corporation has developed a white LED with luminous efficacy of 150 lm/W at a
forward current of 20 mA. Cree's Lamp XM-L LEDs, commercially available in 2011, produce
100 lm/W at their full power of 10 W, and up to 160 lm/W at around 2 W input powers. In
2012, Cree announced a white LED giving 254 lm/W and 303 lm/W in March 2014.Practical
general lighting needs high-power LEDs, of one watt or more. Typical operating currents for
such devices begin at the 350 mA.
These efficiencies are for the light-emitting diode only, held at low temperature in a lab.
Since LEDs installed in real fixtures operate at higher temperature and with driver losses, realworld efficiencies are much lower. United States Department of Energy (DOE) testing of
commercial LED lamps designed to replace incandescent lamps or CFLs showed that average
efficacy was still about 46 lm/W in 2009 (tested performance ranged from 17 lm/W to
79 lm/W).
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 13
RAILWAY TRACK SECURITY SYSTEM
Advantages
 Efficiency: LEDs emit more lumens per watt than incandescent light bulbs. The
efficiency of LED lighting fixtures is not affected by shape and size, unlike fluorescent
light bulbs or tubes.
 Color: LEDs can emit light of an intended color without using any color filters as
traditional lighting methods need. This is more efficient and can lower initial costs.
 Size: LEDs can be very small (smaller than 2 mm and are easily attached to printed
circuit boards.
 Warm-up time: LEDs light up very quickly. A typical red indicator LED to achieves
full brightness in under a microsecond.LEDs used in communications devices can have
even faster response times.
 Cycling: LEDs are ideal for uses subject to frequent on-off cycling, unlike incandescent
and fluorescent lamps that fail faster when cycled often, or high intensity discharge lamp
(HID lamps) that require a long time before restarting.
 Dimming: LEDs
can
very
easily
can
be the
dimmed either
by pulse-width
modulation or lowering the forward current. This pulse-width modulation is why LED
lights, particularly headlights on cars, when viewed on camera or by some people, seem
to flash or flicker. This is a type of stroboscopic effect.
 Cool light: In contrast to most light sources, LEDs radiate very little heat in the form
of IR that can cause damage to sensitive objects or fabrics. Wasted energy is dispersed as
heat through the base of the LED.
 Slow failure: LEDs mainly fail by dimming over time, rather than the abrupt failure of
incandescent bulbs.
 Lifetime: LEDs can have a relatively long useful life. One report estimates 35,000 to
50,000 hours of useful life, though time to complete failure may be shorter or longer.
Fluorescent tubes typically are rated at about 10,000 to 25,000 hours, depending partly on
the conditions of use, and incandescent light bulbs at 1,000 to 2,000 hours.
Several DOE demonstrations have shown that reduced maintenance costs from this
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 14
RAILWAY TRACK SECURITY SYSTEM
extended lifetime, rather than energy savings, is the primary factor in determining the
payback period for an LED product.
 Shock resistance: LEDs, being solid-state components, are difficult to damage with
external shock, unlike fluorescent and incandescent bulbs, which are fragile
 Focus: The solid package of the LED can be designed to focus its light. Incandescent
and fluorescent sources often require an external reflector to collect light and direct it in a
usable manner. For larger LED packages total internal reflection (TIR) lenses are often
used to the same effect. However, when large quantities of light are needed many light
sources are usually deployed, which are difficult to focus or collimate towards the same
target.
Applications
LED uses fall into four major categories:
 Visual signals where light goes more or less directly from the source to the human eye, to
convey a message or meaning
 Illumination where light is reflected from objects to give visual response of these objects
 Measuring and interacting with processes involving no human vision Narrow band light
sensors where LEDs operate in a reverse-bias mode and respond to incident light, instead
of emitting light.
3.2.2 LDR (Light Dependent Resistor)
The dominant of street lights, outside lights, a number of indoor home appliances, and so
on are typically operated and maintained manually on many occasions. This is not only risky,
however additionally leads to wastage of power with the negligence of personnel or uncommon
circumstances in controlling these electrical appliances ON and OFF. Hence, we can utilize the
light sensor circuit for automatic switch OFF the loads based on daylight’s intensity by
employing a light sensor. This article discusses in brief about what is a light dependent resistor,
how to make a light dependent resistor circuit and its applications.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 15
RAILWAY TRACK SECURITY SYSTEM
Fig.3.5: Circuit Symbol of LDR
An LDR or light dependent resistor is also known as photo resistors, photocell, and
photoconductor. It is a one type of resistor whose resistance varies depending on the amount of light
falling on its surface. When the light falls on the resistor, then the resistance changes. These resistors are
often used in many circuits where it is required to sense the presence of light. These resistors have a
variety of functions and resistance. For instance, when the LDR is in darkness, then it can be used to turn
ON a light or to turn OFF a light when it is in the light. A typical light dependent resistor has a resistance
in the darkness of 1MOhm, and in the brightness a resistance of a couple of KOhm.
 Working Principle of LDR
This resistor works on the principle of photo conductivity. It is nothing but, when the
light falls on its surface, then the material conductivity reduces and also the electrons in the
valence band of the device are excited to the conduction band. These photons in the incident
light must have energy greater than the band gap of the semiconductor material. This makes the
electrons to jump from the valence band to conduction.
These resistors are often used in many circuits where it is required to sense the presence
of light. These resistors have a variety of functions and resistance. For instance, when the LDR is
in darkness, then it can be used to turn ON a light or to turn OFF a light when it is in the light.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 16
RAILWAY TRACK SECURITY SYSTEM
Fig.3.6: Working Principle of LDR
These devices depend on the light, when light falls on the LDR then the resistance
decreases, and increases in the dark. When a LDR is kept in the dark place, its resistance is high
and, when the LDR is kept in the light its resistance will decrease.
Fig.3.7: Variation of LDR Resistance with Variation in Light Intensity
If a constant “V’ is applied to the LDR, the intensity of the light increased and current
increases. The figure below shows the curve between resistance Vs illumination curve for a
particular light dependent resistor.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 17
RAILWAY TRACK SECURITY SYSTEM
Fig.3.8: Light Intensity vs LDR Resistance
Types of light Dependent Resistors
Light dependent resistors are classified based on the materials used.
 Intrinsic Photo Resistors
These resistors are pure semiconductor devices like silicon or germanium. When the light
falls on the LDR, then the electrons get excited from the valence band to the conduction band
and number of charge carriers increases.
 Extrinsic Photo Resistors
These devices are doped with impurities and these impurities create a new energy bands
above the valence band. These bands are filled with electrons. Hence this decrease the band gap
and small amount of energy is required in moving them. These resistors are mainly used for long
wavelengths.
 Circuit Diagram of a Light Dependent Resistor
The circuit diagram of a LDR is shown below. When the light intensity is low, then the
resistance of the LDR is high. This stops the current flow to the base terminal of the transistor.
So, the LED does not light. However, when the light intensity onto the LDR is high, then the
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 18
RAILWAY TRACK SECURITY SYSTEM
resistance of the LDR is low. So current flows onto the base of the first transistor and then the
second transistor. Consequently the LED lights. Here, a preset resistor is used to turn up or down
to increase or decrease the resistance.
Fig.3.9: Light Dependent Resistor Circuit
 Light Dependent Resistor Applications
Light dependent resistors have a low cost and simple structure. These resistors are
frequently used as light sensors. These resistors are mainly used when there is a need to sense the
absence and presence of the light such as burglar alarm circuits, alarm clock, light intensity
meters, etc. LDR resistors mainly involves in various electrical and electronic projects. For better
understanding of this concept, here we are explaining some real time projects were the LDR
resistors are used.
3.2.3 GPS (GLOBAL POSITIONING SYSTEM)
The Global Positioning System (GPS) is a U.S. space-based radio navigation system
that provides reliable positioning, navigation, and timing services to civilian users on a
continuous worldwide basis -- freely available to all. For anyone with a GPS receiver, the system
will provide location and time. GPS provides accurate location and time information for an
unlimited number of people in all weather, day and night, anywhere in the world.
The GPS is made up of three parts:
1. Satellites orbiting the Earth
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 19
RAILWAY TRACK SECURITY SYSTEM
2. Control and monitoring stations on Earth
3. The GPS receivers owned by users.
GPS satellites broadcast signals from space that are picked up and identified by GPS receivers.
Each GPS receiver then provides three-dimensional location (latitude, longitude, and altitude)
plus the time.
1. SPACE SEGMENT

24+ satellites

20,200 km altitude

55 degrees inclination

12 hour orbital period

5 ground control stations

Each satellite passes over a ground monitoring station every 12 hours
Fig.3.10: GPS satellite system
The space segment is composed of the orbiting GPS satellites or Space Vehicles (SV) in
GPS parlance. The GPS design originally called for 24 SVs, this was modified to six planes
with four satellites each. The orbital planes are centered on the Earth, not rotating with respect
to the distant stars. The six planes have approximately 55° inclination (tilt relative to Earth's
equator) and are separated by 60° right ascension of the ascending node (angle along the equator
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 20
RAILWAY TRACK SECURITY SYSTEM
from a reference point to the 1orbit's intersection). The orbits are arranged so that at least six
satellites are always within line of sight from almost everywhere on Earth's surface.
The full constellation of 24 satellites that make up the GPS space segment are orbiting
the earth about 20,200 km above us. They are constantly moving, making two complete orbits
in less than 24 hours. These satellites are travelling at speeds of roughly 7,000 miles an hour.
GPS satellites are powered by solar energy. They have backup batteries onboard to keep
them running in the event of a solar eclipse, when there's no solar power. Small rocket boosters
on each satellite keep them flying in the correct path.
Here are some other interesting facts about the GPS satellites (also called NAVSTAR, the
official U.S. Department of Defense name for GPS):

The first GPS satellite was launched in 1978.

A full constellation of 24 satellites was achieved in 1994.

Each satellite is built to last about 10 years. Replacements are constantly being built and
launched into orbit.

A GPS satellite weighs approximately 2,000 pounds and is about 17 feet across with the
solar panels extended.

Transmitter power is only 50 watts or less.

The orbits are arranged so that at any time, anywhere on Earth, there are at least four
satellites "visible" in the sky.

All satellites broadcast at the same two frequencies, 1.57542 GHz (L1 signal) and
1.2276 GHz (L2 signal).

The satellite network uses a CDMA spread-spectrum technique where the low-bitrate
message data is encoded with a high-rate pseudo-random (PRN) sequence that is different
for each satellite.
The receiver must be aware of the PRN codes for each satellite to
reconstruct the actual message data. The C/A code, for civilian use, transmits data at
1.023 million chips per second, whereas the P code, for U.S. military use, transmits at
10.23 million chips per second. The L1 carrier is modulated by both the C/A and
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 21
RAILWAY TRACK SECURITY SYSTEM
P codes, while the L2 carrier is only modulated by the P code. The P code can be
encrypted as a so-called P(Y) code which is only available to military equipment with a
proper decryption key. Both the C/A and P(Y) codes impart the precise time-of-day to
the user
2. Control and monitoring stations on Earth
Ground Stations (also known as the "Control Segment")
These stations monitor the GPS satellites, checking both their operational health and
their exact position in space. The master ground station transmits corrections for the
satellite's ephemeris constants and clock offsets back to the satellites themselves. The
satellites can then incorporate these updates in the signals they send to GPS receivers.
There are five monitor stations: Hawaii, Ascension Island, Diego Garcia, Kwajalein,
and Colorado Springs.
Each GPS satellite regularly with a navigational update using dedicated or shared
ground antennas (GPS dedicated ground antennas are located at Kwajalein, Ascension
Island, Diego Garcia, and Cape Canaveral). These updates synchronize the atomic clocks
on board the satellites to within a few nanoseconds of each other, and adjust the ephemeris
of each satellite's internal orbital model. The updates are created by a Kalman filter, which
uses inputs from the ground monitoring stations, space weather information, and various
other inputs. Satellite maneuvers are not precise by GPS standards. So to change the orbit
of a satellite, the satellite must be marked unhealthy, so receivers will not use it in their
calculation. Then the maneuver can be carried out, and the resulting orbit tracked from the
ground. Then the new ephemeris is uploaded and the satellite marked healthy again.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 22
RAILWAY TRACK SECURITY SYSTEM
3.The GPS receivers

Receiver determines location, speed, direction, and time

3 satellite signals are necessary to locate the receiver in 3D space

4th satellite is used for time accuracy

Position calculated within sub-centimeter scale
Individuals may purchase GPS handsets that are readily available through commercial
retailers. Equipped with these GPS receivers, users can accurately locate where they are and
easily navigate to where they want to go, whether walking, driving, flying, or boating.
Today's GPS receivers are extremely accurate, thanks to their parallel multichannel design. Garmin's 12 parallel channel receivers are quick to lock onto satellites
when first turned on and they maintain strong locks, even in dense foliage or urban settings
with tall buildings. Certain atmospheric factors and other sources of error can affect the
accuracy of GPS receivers. Garmin® GPS receivers are accurate to within 15 meters on
average.

Newer Garmin GPS receivers with WAAS (Wide Area Augmentation
System) capability can improve accuracy to less than three meters on average. No additional
equipment or fees are required to take advantage of WAAS. Users can also get better accuracy
with Differential GPS (DGPS), which corrects GPS signals to within an average of three to five
meters. The U.S. Coast Guard operates the most common DGPS correction service. This system
consists of a network of towers that receive GPS signals and transmit a corrected signal by
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 23
RAILWAY TRACK SECURITY SYSTEM
beacon transmitters. In order to get the corrected signal, users must have a differential beacon
receiver and beacon antenna in addition to their GPS.
Our ancestors had to go to pretty extreme measures to keep from getting lost. They erected
monumental landmarks, laboriously drafted detailed maps and learned to read the stars in the
night sky.
Things are much, much easier today. For less than $100, you can get a pocket-sized gadget that
will tell you exactly where you are on Earth at any moment. As long as you have a GPS receiver
and a clear view of the sky, you'll never be lost again.
The user segment is composed of hundreds of thousands of U.S. and allied military users
of the secure GPS Precise Positioning Service, and tens of millions of civil, commercial and
scientific users of the Standard Positioning Service. In general, GPS receivers are composed of
an antenna, tuned to the frequencies transmitted by the satellites, receiver-processors, and a
highly stable clock (often a crystal oscillator). They may also include a display for providing
location and speed information to the user. A receiver is often described by its number of
channels: this signifies how many satellites it can monitor simultaneously. Originally limited to
four or five, this has progressively increased over the years so that, as of 2007, receivers
typically have between 12 and 20 channels.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 24
RAILWAY TRACK SECURITY SYSTEM
The Global Positioning System is vast, expensive and involves a lot of technical ingenuity, but
the fundamental concepts at work are quite simple and intuitive.
When people talk about "a GPS," they usually mean a GPS receiver. The Global Positioning
System (GPS) is actually a constellation of 24 Earth-orbiting satellites The U.S. military
developed and implemented this satellite network as a military navigation system, but soon
opened it up to everybody else.
Each of these 3,000- to 4,000-pound solar-powered satellites circles the globe making two
complete rotations every day. The orbits are arranged so that at any time, anywhere on Earth,
there are at least four satellites "visible" in the sky.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 25
RAILWAY TRACK SECURITY SYSTEM
A GPS receiver's job is to locate four or more of these satellites, figure out the distance to
each, and use this information to deduce its own location. This operation is based on a simple
mathematical principle called trilateration. Trilateration in three-dimensional space can be a little
tricky, so we'll start with an explanation of simple two-dimensional trilateration.
APPLICATIONS OF GPS

GPS has become a mainstay of transportation systems worldwide,

Providing navigation for aviation, ground, and maritime operations.

Disaster relief and emergency services depend upon GPS for location and timing
capabilities in their life-saving missions.

Everyday activities such as banking,

Mobile phone operations, and even

The control of power grids, are facilitated by the accurate timing provided by
GPS.

Farmers, surveyors, geologists and countless others perform their work more
efficiently, safely, economically, and accurately using the free and open GPS
signals.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 26
RAILWAY TRACK SECURITY SYSTEM
3.3 Technology
3.3.1 Arduino
Arduino Uno is a microcontroller board based on 8-bit ATmega328P microcontroller.
Along with ATmega328P, it consists of other components such as crystal oscillator, serial
communication, voltage regulator, etc. to support the microcontroller. Arduino Uno has 14
digital input/output pins (out of which 6 can be used as PWM outputs), 6 analog input pins, a
USB connection, A Power barrel jack, an ICSP header and a reset button.
The 14 digital input/output pins can be used as input or output pins by using pinMode()
and digitalRead() and digitalWrite() functions in the arduino to the programming. Each pin
operate at 5V and can provide or receive a maximum of 40mA current, and has an internal pullup resistor of 20-50 KOhms which are disconnected by default. Out of these 14 pins, some pins
have specific functions as listed below:

Serial Pins 0 (Rx) and 1 (TX): Rx and Tx pins are used to receive and transmit
TTL serial data. They are connected with the corresponding ATmega328P USB to TTL
serial chip.

External Interrupt Pins 2 and 3: These pins can be configured to trigger an
interrupt on a low value, a rising or falling edge, or a change in value.

PWM Pins 3, 5, 6, 9 and 11: These pins provide an 8-bit PWM output by using
analogWrite() function.

SPI Pins 10 (SS), 11 (MOSI), 12 (MISO) and 13 (SCK): These pins are used
for SPI communication.

In-built LED Pin 13: This pin is connected with an built-in LED, when pin 13 is
HIGH – LED is on and when pin 13 is LOW, it’s off.
Along with 14 Digital pins, there are 6 analog input pins, each of which provides 10
bits of resolution, i.e. 1024 different values. They measure from 0 to 5 volts but this limit
can be increased by using AREF pin with analog Reference () function.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 27
RAILWAY TRACK SECURITY SYSTEM
Analog pin 4 (SDA) and pin 5 (SCA) also used for TWI communication using Wire
library.
Fig.3.11: Arduino Board
Table No.3.2: Pin Description of Arduino
Pin
Category
Pin Name
Details
Vin: Input voltage to Arduino when using
an external power source.
Power
Vin,3.3V,
5V, GND
5V: Regulated power supply used to power
microcontroller and other components on
the board.
3.3V: 3.3V supply generated by on-board
voltage regulator. Maximum current draw
is 50mA.
GND: ground pins.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 28
RAILWAY TRACK SECURITY SYSTEM
Reset
Reset
Resets the microcontroller.
Analog Pins
A0 – A5
Input/output
Pins
Digital Pins
0 - 13
Can be used as input or output pins.
Serial
0(Rx),1(Tx)
Used to receive and transmit TTL serial
data.
Used to provide analog input in the range
of 0-5V
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 29
RAILWAY TRACK SECURITY SYSTEM
External
Interrupts
2, 3
PWM
3, 5, 6, 9, 11
To trigger an interrupt.
Provides 8-bit PWM output.
10(SS),
11(MOSI),
SPI
12 (MISO)
and
Used for SPI communication.
13 (SCK)
Inbuilt LED
13
To turn on the inbuilt LED.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 30
RAILWAY TRACK SECURITY SYSTEM
TWI
A4 (SDA),
A5 (SCA)
AREF
AREF
Used for TWI communication.
To provide reference voltage for input
voltage.
Arduino Uno has a couple of other pins as explained below:
 AREF: Used to provide reference voltage for analog inputs with analog Reference ()
function.
 Reset Pin: Making this pin LOW, resets the microcontroller.
Table No.3.3: Arduino Uno Technical Specifications
Microcontroller
Operating Voltage
Recommended Input
Voltage
Input Voltage Limits
Analog Input Pins
ATmega328p – 8 bit AVR family microcontroller
5V
7-12V
6-20V
6 (A0 – A5)
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 31
RAILWAY TRACK SECURITY SYSTEM
Digital I/O Pins
14 (Out of which 6 provide PWM output)
DC Current on I/O Pins
40 Ma
DC Current on 3.3V Pin
50 mA
Flash Memory
32 KB (0.5 KB is used for Boot loader)
SRAM
2 KB
EEPROM
1 KB
Frequency (Clock Speed)
16 MHz
Arduino can be used to communicate with a computer, another arduino board or other
microcontrollers. The ATmega328P microcontroller provides UART TTL (5V) serial
communication which can be done using digital pin 0 (Rx) and digital pin 1 (TX). An
ATmega16U2 on the board channels this serial communication over USB and appears as a
virtual com port to software on the computer. The ATmega16U2 firmware uses the standard
USB COM drivers, and no external driver is needed. However, on Windows, a .info file is
required. The arduino software includes a serial monitor which allows simple textual data to be
sent to and from the arduino board. There are two RX and TX LEDs on the arduino board which
will flash when data is being transmitted via the USB-to-serial chip and USB connection to the
computer (not for serial communication on pins 0 and 1). A Software Serial library allows for
serial communication on any of the Uno's digital pins. The ATmega328P also supports I2C
(TWI) and SPI communication. The Arduino software includes a Wire library to simplify use of
the I2C bus.
3.3.2 Atmega328
The Atmega328 is a very popular microcontroller chip produced by Atmel. It is an 8-bit
microcontroller that has 32K of flash memory, 1K of EEPROM, and 2K of internal SRAM.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 32
RAILWAY TRACK SECURITY SYSTEM
The Atmega328 is one of the microcontroller chips that are used with the popular
Arduino Duemilanove boards. The Arduino Duemilanove board comes with either 1 of 2
microcontroller chips, the Atmega168 or the Atmega328. Of these 2, the Atmega328 is the
upgraded, more advanced chip. Unlike the Atmega168 which has 16K of flash program memory
and 512 bytes of internal SRAM, the Atmega328 has 32K of flash program memory and 2K of
Internal SRAM.
Fig.3.12: Pin Diagram
 Specifications
The Atmega328 has 28 pins. It has 14 digital I/O pins, of which 6 can be used as PWM
outputs and 6 analog input pins. These I/O pins account for 20 of the pins.
Table No.3.4: Key Parameters of Atmega328
Parameter
CPU type
Performance
Value
8-bit AVR
20 MIPS at 20 MHz
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 33
RAILWAY TRACK SECURITY SYSTEM
Flash memory
32 kB
SRAM
2 kB
EEPROM
1 kB
28 or 32 pin: PDIP-28, MLF-28, TQFP-32
Pin count
MLF-32
Maximum operating
frequency
20 MHz
Number of touch channels
16
Hardware Touch Acquisition
No
Maximum I/O pins
23
External interrupts
2
USB Interface
No
–
USB Speed
The ATmega328 is
a
single-chip microcontroller created
that
is
by Atmel in
the megaAVR family (later Microchip Technology acquired Atmel in 2016). It has a modified
Harvard architecture 8-bit RISC processor core.
The
Atmel 8-bit AVR RISC-based
32 kB ISP flash memory
with
the
microcontroller
read-while-write
is
used
capabilities,
to
combines
and1 kB EEPROM,
2 kB SRAM, 23 general purpose I/O lines, 32 general purpose working registers, three flexible
timer/counters with
compare
modes,
internal
and
external interrupts,
serial
programmable USART, a byte-oriented 2-wire serial interface, SPI serial port, 6-channel and
10-bit A/D converter (8-channels in TQFP and QFN/MLF packages), programmable watchdog
timer with internal oscillator, and five software selectable power saving modes. The device
operates between 1.8-5.5 volts. The device achieves throughput approaching 1 MIPS per MHz
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 34
RAILWAY TRACK SECURITY SYSTEM
As of 2013 the ATmega328 is commonly used in many projects and autonomous
systems where a simple, low-powered, low-cost micro-controller is needed Perhaps the most
common implementation of this chip is on the popular Arduino development platform, namely
to the Arduino Uno and Arduino Nano model.
As stated before, 20 of the pins function as I/O ports. This means they can function as an
input to the circuit or as output. Whether they are input or output is set in the software. 14 of the
pins are digital pins, of which 6 can function to give PWM output. 6 of the pins are for analog
input/output.2 of the pins are for the crystal oscillator. This is to provide a clock pulse for the
Atmega chip. A clock pulse is needed for synchronization so that communication can occur in
synchrony between the Atmega chip and a device.
The chip needs power so 2 of the pins, VCC and GND, provide it power so that it can
operate. The Atmega328 is a low-power chip, so it only needs between 1.8-5.5V of power to
operate.
The Atmega328 chip has an analog-to-digital converter (ADC) inside of it. This must be
or else the Atmega328 wouldn't be capable of interpreting analog signals. Because there is an
ADC, the chip can interpret analog input, which is why the chip has 6 pins for analog input. The
ADC has 3 pins set aside for it to function- AVCC, AREF, and GND. AVCC is the power
supply, positive voltage, that for the ADC. The ADC needs its own power supply in order to
work. GND is the power supply ground. AREF is the reference voltage that the ADC uses to
convert an analog signal to its corresponding digital value. Analog voltages higher than the
reference voltage will be assigned to a digital value of 1, while analog voltages below the
reference voltage will be assigned the digital value of 0.
Table No.3.5: Pin Description of Atmega328
Pin
Number
Description
Function
1
PC6
Reset
2
PD0
Digital Pin (RX)
3
PD1
Digital Pin (TX)
4
PD2
Digital Pin
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 35
RAILWAY TRACK SECURITY SYSTEM
5
PD3
Digital Pin (PWM)
6
PD4
Digital Pin
7
VCC
Positive Voltage (Power)
8
GND
Ground
9
XTAL 1
Crystal Oscillator
10
XTAL 2
Crystal Oscillator
11
PD5
Digital Pin (PWM)
12
PD6
Digital Pin (PWM)
13
PD7
Digital Pin
14
PB0
Digital Pin
15
PB1
Digital Pin (PWM)
16
PB2
Digital Pin (PWM)
17
PB3
Digital Pin (PWM)
18
PB4
Digital Pin
19
PB5
Digital Pin
20
AVCC
21
AREF
Reference Voltage
22
GND
Ground
23
PC0
Analog Input
24
PC1
Analog Input
25
PC2
Analog Input
26
PC3
Analog Input
27
PC4
Analog Input
28
PC5
Analog Input
Positive voltage for ADC (power)
Since the ADC for the Atmega328 is a 10-bit ADC, meaning it produces a 10-bit digital value, it
converts an analog signal to its digital value, with the AREF value being a reference for which
digital values are high or low. Thus, a portrait of an analog signal is shown by this digital value;
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 36
RAILWAY TRACK SECURITY SYSTEM
thus, it is its digital correspondent value. The last pin is the RESET pin. This allows a program to
be rerun and start over. And this sums up the pin out of an Atmega328 chip.
3.4 Outputs
3.4.1 Buzzer
Fig.3.13: Buzzer
Basically, the sound source of a piezoelectric sound component is a piezoelectric
diaphragm. A piezoelectric diaphragm consists of a piezoelectric ceramic plate which has
electrodes on both sides and a metal plate (brass or stainless steel, etc.). A piezoelectric ceramic
plate is attached to a metal plate with adhesives. Applying D.C. voltage between electrodes of a
piezoelectric diaphragm causes mechanical distortion due to the piezoelectric effect. For a
misshaped piezoelectric element, the distortion of the piezoelectric element expands in a radial
direction. And the piezoelectric diaphragm bends toward the direction. The metal plate bonded
to the piezoelectric element does not expand. Conversely, when the piezoelectric element
shrinks, the piezoelectric diaphragm bends in the direction Thus, when AC voltage is applied
across electrodes, the bending is repeated, producing sound waves in the air.
Piezo buzzer is an electronic device commonly used to produce sound. Light weight,
simple construction and low price make it usable in various applications like car/truck reversing
indicator, computers, call bells etc. Piezo buzzer is based on the inverse principle of piezo
electricity discovered in 1880 by Jacques and Pierre Curie. It is the phenomena of generating
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 37
RAILWAY TRACK SECURITY SYSTEM
electricity when mechanical pressure is applied to certain materials and the vice versa is also
true. Such materials are called piezo electric materials. Piezo electric materials are either
naturally available or manmade. Piezoceramic is class of manmade material, which poses piezo
electric effect and is widely used to make disc, the heart of piezo buzzer. When subjected to an
alternating electric field they stretch or compress, in accordance with the frequency of the signal
thereby producing sound.
Fig.3.14: Circuit Diagram for Buzzer
Certain materials will generate a measurable potential difference when they are made
to expand or shrink in a particular direction.
Increasing or decreasing the space between the atoms by squeezing, hitting, or bending
the crystal can cause the electrons to redistribute themselves and cause electrons to leave the
crystal, or create room for electrons to enter the crystal. A physical force on the crystal creates
the electromotive force that moves charges around a circuit.
The opposite is true as well: Applying an electric field to a piezoelectric crystal leads
to the addition or removal of electrons, and this in turn causes the crystal to deform and
thereby generate a small physical force.
The piezoelectric effect can be employed in the construction of thin-form-factor
speakers that are valuable alternatives to traditional electrodynamics speakers in spaceconstrained applications. These devices are referred to as both piezo speakers and ceramic
speakers.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 38
RAILWAY TRACK SECURITY SYSTEM
Apply an electric field to a piezoelectric material and it will change size. The
piezoelectric material will shrink or grow as charges are introduced or removed, but the base
material will not.
This causes elastic deformation of the material toward or away from a direction that is
perpendicular to the surface of the speaker. As soon as the electric field is removed from the
piezoelectric material, it will return to its original shape.
As the speaker flexes and strikes air molecules, it causes a chain reaction of collisions
that eventually reaches your ear. If enough air molecules strike your ear, the nerve cells send a
signal to your brain that you interpret as sound.
3.4.2 LCD MODULE
To display interactive messages we are using LCD Module. We examine an intelligent
LCD display of two lines, 16 characters per line that is interfaced to the controllers. The
protocol (handshaking) for the display is as shown. Whereas D0 to D7th bit is the Data lines,
RS, RW and EN pins are the control pins and remaining pins are +5V, -5V and GND to provide
supply. Where RS is the Register Select, RW is the Read Write and EN is the Enable pin.
The display contains two internal byte-wide registers, one for commands (RS=0) and
the second for characters to be displayed (RS=1). It also contains a user-programmed RAM area
(the character RAM) that can be programmed to generate any desired character that can be
formed using a dot matrix. To distinguish between these two data areas, the hex command byte
80 will be used to signify that the display RAM address 00h will be chosen.Port1 is used to
furnish the command or data type, and ports 3.2 to 3.4 furnish register select and read/write
levels.
The display takes varying amounts of time to accomplish the functions as listed. LCD bit
7 is monitored for logic high (busy) to ensure the display is overwritten.
Liquid Crystal Display also called as LCD is very helpful in providing user interface as
well as for debugging purpose. The most common type of LCD controller is HITACHI 44780
which provides a simple interface between the controller & an LCD. These LCD's are very
simple to interface with the controller as well as are cost effective.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 39
RAILWAY TRACK SECURITY SYSTEM
Fig.3.15: 2x16 Line Alphanumeric LCD Display
The most commonly used ALPHANUMERIC displays are 1x16 (Single Line & 16
characters), 2x16 (Double Line & 16 character per line) & 4x20 (four lines & Twenty characters
per line).
The LCD requires 3 control lines (RS, R/W & EN) & 8 (or 4) data lines. The number on
data lines depends on the mod1e of operation. If operated in 8-bit mode then 8 data lines + 3
control lines i.e. total 11 lines are required. And if operated in 4-bit mode then 4 data lines + 3
control lines i.e. 7 lines are required. How do we decide which mode to use? It’s simple if you
have sufficient data lines you can go for 8 bit mode & if there is a time constrain i.e. display
should be faster then we have to use 8-bit mode because basically 4-bit mode takes twice as
more time as compared to 8-bit mode.
Pin
1
2
3
4
5
Symbol
Function
Vss
Ground
Vdd
Supply Voltage
Vo
Contrast Setting
RS
Register Select
R/W
Read/Write Select
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 40
RAILWAY TRACK SECURITY SYSTEM
6
7-14
15
16
En
DB0-DB7
Chip Enable Signal
Data Lines
A/Vee
Gnd for the backlight
K
Vcc for backlight
When RS is low (0), the data is to be treated as a command. When RS is high (1), the data being
sent is considered as text data which should be displayed on the screen.
When R/W is low (0), the information on the data bus is being written to the LCD. When
RW is high (1), the program is effectively reading from the LCD. Most of the times there is no
need to read from the LCD so this line can directly be connected to Gnd thus saving one
controller line.
The ENABLE pin is used to latch the data present on the data pins. A HIGH - LOW signal
is required to latch the data. The LCD interprets and executes our command at the instant the
EN line is brought low. If you never bring EN low, your instruction will never be executed.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 41
RAILWAY TRACK SECURITY SYSTEM
COMMANDS USED IN LCD
3.4.3 GSM
Definitions :
The words, “Mobile Station” (MS) or “Mobile Equipment” (ME) are used for mobile
terminals Supporting GSM services.
A call from a GSM mobile station to the PSTN is called a “mobile originated call” (MOC)
or
“Outgoing call”, and a call from a fixed network to a GSM mobile station is called a
“mobile
Terminated call” (MTC) or “incoming call”.
Fig.3.16:GSM Module
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 42
RAILWAY TRACK SECURITY SYSTEM
What is GSM ?
GSM (Global System for Mobile communications) is an open, digital cellular
technology used for transmitting mobile voice and data services.
What does GSM offer ?
GSM supports voice calls and data transfer speeds of up to 9.6 kbit/s, together with the
transmission of SMS (Short Message Service).
GSM operates in the 900MHz and 1.8GHz bands in Europe and the 1.9GHz and
850MHz bands in the US. The 850MHz band is also used for GSM and 3G in Australia, Canada
and many South American countries. By having harmonised spectrum across most of the globe,
GSM’s international roaming capability allows users to access the same services when
travelling abroad as at home. This gives consumers seamless and same number connectivity in
more than 218 countries.
Terrestrial GSM networks now cover more than 80% of the world’s population. GSM
satellite roaming has also extended service access to areas where terrestrial coverage is not
available.
HISTORY
In 1980’s the analog cellular telephone systems were growing rapidly all throughout
Europe, France and Germany. Each country defined its own protocols and frequencies to work
on. For example UK used the Total Access Communication System (TACS), USA used the
AMPS technology and Germany used the C-netz technology. None of these systems were
interoperable and also they were analog in nature.
In 1982 the Conference of European Posts and Telegraphs (CEPT) formed a study group
called the GROUPE SPECIAL MOBILE (GSM) The main area this focused on was to get the
cellular system working throughout the world, and ISDN compatibility with the ability to
incorporate any future enhancements. In 1989 the GSM transferred the work to the European
Telecommunications Standards Institute (ETSI.) the ETS defined all the standards used in
GSM.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 43
RAILWAY TRACK SECURITY SYSTEM
3.5 Power Supply
Fig.3.17: Power Supply Diagram
3.5.1 Step down Transformer
A Step down Transformer is a type of transformer, which converts a high voltage at the
primary side to a low voltage at the secondary side.
If we speak in terms of the coil windings, the primary winding of a Step down
Transformer has more turns than the secondary winding. The following image shows a typical
step down transformer.
A Transformer is a static apparatus, with no moving parts, which transforms electrical
power from one circuit to another with changes in voltage and current and no change in
frequency. There are two types of transformers classified by their function: Step up Transformer
and Step down Transformer.
A Step up Transformer is a device which converts the low primary voltage to a high
secondary voltage i.e. it steps up the input voltage. A Step down Transformer on the other hand,
steps down the input voltage i.e. the secondary voltage is less than the primary voltage.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 44
RAILWAY TRACK SECURITY SYSTEM
 Principle of Working of a Transformer
Fig.3.18: Step down Transformer
An electrical transformer works on the principle of Mutual Induction, which states that a
uniform change in current in a coil will induce an E.M.F in the other coil which is inductively
coupled to the first coil.
In its basic form, a transformer consists of two coils with high mutual inductance that are
electrically separated but have common magnetic circuit. The following image shows the basic
construction of a Transformer.
The first set of the coil, which is called as the Primary Coil or Primary Winding, is
connected to an alternating voltage source called Primary Voltage.
The other coil, which is called as Secondary Coil or Secondary Winding, is connected to
the load and the load draws the resulting alternating voltage (stepped up or stepped down
voltage).
The alternating voltage at the input excites the Primary Winding, an alternating current
circulates the winding. The alternating current will result in an alternating magnetic flux, which
passes through the iron magnetic core and completes its path.
Since the secondary winding is also linked to the alternating magnetic flux, according to
Faraday’s Law, an E.M.F is induced in the secondary winding. The strength of the voltage at the
secondary winding is dependent on the number of windings through which the flux gets passed
through.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 45
RAILWAY TRACK SECURITY SYSTEM
Thus, without making an electrical contact, the alternating voltage in the primary winding
is transferred to the secondary winding.
Note: Depending on the construction of the transformer, the voltage at the secondary of the
transformer may be equal, higher or lower than that at the primary of the transformer but the time
period of the voltage i.e. its frequency will not change.
3.5.2 Bridge Rectifier
Before going to bridge rectifier, we need to know what actually a rectifier is and what the
need for a rectifier is. So first let’s take a look at the evolution of rectifiers.
 Evolution of rectifiers
Rectifiers are mainly classified into three types: Half-wave rectifier, Centre tapped fullwave rectifier and Bridge rectifier. All these three rectifiers have a common aim that is to
convert Alternating into Direct Current (DC).
Not all these three rectifiers efficiently convert the Alternating Current (AC) into Direct
Current (DC), only the centre tapped full-wave rectifier and bridge rectifier efficiently convert
the Alternating Current (AC) into Direct Current (DC).
 Half wave rectifier
In half wave rectifier, only 1 half cycle is allowed and the remaining half cycle is
blocked. As a result, nearly half of the applied power is wasted in half wave rectifier. In
addition to this, the output current or voltage produced by half wave rectifier is not a pure DC
but a pulsating DC which is not much useful.
Fig.3.19: Half Wave Rectifier
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 46
RAILWAY TRACK SECURITY SYSTEM
 Full wave rectifier
The main advantage of centre tapped full wave rectifier is that it allows electric current
during both positive and negative half cycles of the input AC signal. As a result, the DC output
of the centre tapped full wave rectifier is double of that of a half-wave rectifier. In addition to
this, the DC output of centre tapped full wave rectifier contains very fewer ripples. As a result,
the DC output of the centre tapped full wave rectifier is smoother than the half wave rectifier.
Fig.3.20: Full Wave Rectifier
Bridge rectifier
A bridge rectifier is a type of full wave rectifier which uses four or more diodes in a
bridge circuit configuration to efficiently convert the Alternating Current (AC) into Direct
Current (DC).
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 47
RAILWAY TRACK SECURITY SYSTEM
Fig.3.21: Bridge Rectifier
When input AC signal is applied across the bridge rectifier, during the positive half
cycle diodes D1 and D3 are forward biased and allows electric current while the diodes D 2 and
D4are reverse biased and blocks electric current. On the other hand, during the negative half
cycle diodes D2 and D4 are forward biased and allow electric current while diodes D 1 and D3 are
reverse biased and blocks electric current.
During the positive half cycle, the terminal A becomes positive while the terminal B
becomes negative. This causes the diodes D1 and D3 forward biased and at the same time, it
causes the diodes D2 and D4 reverse biased.
During the negative half cycle, the terminal B becomes positive while the terminal A
becomes negative. This causes the diodes D2 and D4 forward biased and at the same time, it
causes the diodes D1 and D3 reverse biased.
We can observe that the direction of current flow across load resistor RL is same during
the positive half cycle and negative half cycle. Therefore, the polarity of the output DC signal is
same for both positive and negative half cycles. The output DC signal polarity may be either
completely positive or negative. In our case, it is completely positive. If the direction of diodes
is reversed then we get a complete negative DC voltage.
Thus, a bridge rectifier allows electric current during both positive and negative half
cycles of the input AC signal.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 48
RAILWAY TRACK SECURITY SYSTEM
3.5.3 Filter
Filter is a filter circuit in which the first element is a capacitor connected in parallel with
the output of the rectifier in a linear power supply. The capacitor increases the DC voltage and
decreases the ripple voltage components of the output.
The capacitor is often referred to as a smoothing capacitor or reservoir capacitor. The
capacitor is often followed by other alternating series and parallel filter elements to further
reduce ripple voltage, or adjust DC output voltage. It may also be followed by a voltage
regulator which virtually eliminates any remaining ripple voltage, and adjusts the DC voltage
output very precisely to match the DC voltage required by the circuit.
 Operation
During the time the rectifier is conducting and the potential is higher than the charge
across the capacitor, the capacitor will store energy from the transformer; when the output of the
rectifier falls below the charge on the capacitor, the capacitor will discharge energy into the
circuit. Since the rectifier conducts current only in the forward direction, any energy discharged
by the capacitor will flow into the load. These results in output of a DC voltage upon which is
superimposed a waveform referred to as the a sawtooth wave.
The sawtooth wave is to the convenient linear approximation to the actual waveform,
which is exponential for both charge and discharge. The crests of the sawtooth waves will be
more rounded when the DC resistance of the transformer secondary is higher.
3.5.4 Voltage regulator
The voltage regulator is simply an electronic or electrical device which can sustain the
voltage of a power supply within suitable limits. The electrical equipments connected to the
voltage source should bear the value of the voltage. So, the source voltage should be in a certain
range which is acceptable for the connected equipments.
This purpose is fulfilled by implementing a voltage regulator. It regulates the voltage
regardless of the alteration in the input voltage or connected load. It works as a shield for
protective devices from damage. It can regulate AC and DC voltages depending on the design.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 49
RAILWAY TRACK SECURITY SYSTEM
Voltage sources in a circuit may have fluctuations resulting in not providing fixed
voltage outputs. A voltage regulator IC maintains the output voltage at a constant value. 7805
IC, a member of 78xx series of fixed linear voltage regulators used to maintain such
fluctuations, is a popular voltage regulator integrated circuit (IC).
The xx in 78xx indicates the output voltage it provides. 7805 IC provides +5 volts
regulated power supply with provisions to add a heat sink.
In this tutorial, we will see about one of the most commonly used regulator IC’s, the 7805
Voltage Regulator IC. A regulated power supply is very much essential for several electronic
devices due to the semiconductor material employed in them have a fixed rate of current as well
as voltage. The device may get damaged if there is any deviation from the fixed rate.
One of the important sources of DC Supply are Batteries. But using batteries in sensitive
electronic circuits is not a good idea as batteries eventually drain out and lose their potential over
time.
Also, the voltage provided by batteries is typically 1.2V, 3.7V, 9V and 12V. This is good
for circuits whose voltage requirements are in that range. But, most of the TTL IC’s work on 5V
logic and hence we need a mechanism to provide a consistent 5V Supply.
Here comes the 7805 Voltage Regulator IC to the rescue. It is an IC in the 78XX family
of linear voltage regulators that produce a regulated 5V as output.
Fig.3.22: 7805 Voltage Regulator
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 50
RAILWAY TRACK SECURITY SYSTEM
Table No.3.6: Pin Details of 7805 IC
Pin
Function
Description
In this pin of the IC positive
INPUT
Input voltage
(7V-35V)
unregulated voltage is given
in regulation.
In this pin where the ground
GROUND
Ground (0V)
is given. This pin is neutral
for equally the input and
output.
The output of the regulated
OUTPUT
Regulated output
5V (4.8V-5.2V)
5V volt is taken out at this
pin of the IC regulator.
3.6 Software and Hardware Tools
 ARDUINO 1.8.0
 LED
 LDR
 ARDUINO IDE
 Buzzer
3.7 Working principle
We aim to create a new LDR-LED based simple technique to detect cracks in rails that
will be cheap enough, so that it can be put to mass usage. The automatic crack detection
system is constructed using sensors; our scheme consists of a railway line for looking
cracks during night. When local railways don’t operate.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 51
RAILWAY TRACK SECURITY SYSTEM
This crack detection system consists of a LED and LDR assembly that functions as the rail
crack detector. In our project design, the LED and LDR sensors are placed at both sides of
vehicles. If there are no cracks, the LED light does not fall on the LDR and hence the
LDR resistance is high. If there are no crack s on the track the LED light falls on the LDR,
the resistance of the LDR gets reduced. This is detected by a microcontroller and the data
will be displayed on LCD then turns on buzzer.
3.8 Flow Chart
Start
Read Sensor
Detecting Cracks on the
Tracks
If Crack
Present
on Track
LED Light not
Falls on the LDR
LED Light Falls on
LDR
Buzzer ON
Stop
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 52
RAILWAY TRACK SECURITY SYSTEM
CHAPTER-4
SOFTWARE USAGE
4.1 ARDUINO IDE
The Arduino integrated development environment (IDE) then it is the a crossplatform application (for Windows, macOS, Linux) that is written in the programming
language Java. It is used to write and upload programs to Arduino board.
The source code for the IDE is released under the GNU General Public License, version
2. The Arduino IDE supports the languages C and C++ using special rules of code
structuring. The Arduino IDE supplies the a software library from the Wiring project, which
provides many common input and output procedures. User-written code only requires two basic
functions, for starting the sketch and the main program loop, that are compiled and linked with a
program stub main( ) into an executable cyclic executive program with the GNU tool chain, also
included with the IDE distribution.
Fig.4.1: Arduino 1.8.0 window
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 53
RAILWAY TRACK SECURITY SYSTEM
The Arduino IDE employs the program argued to convert the executable code into a text
file in hexadecimal encoding that is loaded into the Arduino board by a loader program in the
board's firmware.
This is the Arduino IDE once it’s been opened. It opens into a blank sketch where you
can start programming immediately. First, we should configure the board and port settings to
allow us to upload code. Connect your Arduino board to the PC via the USB cable.
If you downloaded the Arduino IDE before plugging in your Arduino board, when you
plugged in the board, the USB drivers should have installed automatically. The most recent
Arduino IDE should recognize connected boards and label them with which COM port they are
using. Select the Tools pull down menu and then Port.Here it should list all open COM ports, and
if there is a recognized Arduino Board, it will also give its name. Select the Arduino board that
you have connected to the PC. If the setup was successful, in the bottom right of the Arduino
IDE, you should see the board type and COM number of the board you plan to program.
Note: The Arduino Uno occupies the next available COM port; it will not always be COM3.
Fig.4.2: Arduino 1.8.0 Uploading Blink window
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 54
RAILWAY TRACK SECURITY SYSTEM
One common procedure to test whether the board you are using is properly set up is to
upload the “Blink” sketch. This sketch is included with all Arduino IDE releases and can be
accessed by the Filepull-down menu and going to Examples, 01.Basics, and then select Blink.
Standard Arduino Boards include a surface-mounted LED labeled “L” or “LED” next to the
“RX” and “TX” LEDs that is connected to digital pin 13. This sketch will blink the LED at a
regular interval, and is an easy way to confirm if your board is set up properly and you were
successful in uploading code. Open the “Blink” sketch and press the “Upload” button in the
upper-left corner to upload “Blink” to the board.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 55
RAILWAY TRACK SECURITY SYSTEM
CHAPTER-5
RESULT ANALYSIS
During operation when there are no cracks then the LED light does not falls on the LDR
and hence the LDR resistance is high. When the LED light falls on the LDR automatically the
resistance of LDR will be automatically decreased then crack is detected then buzzer will be on
and it will be displayed on LCD.
Fig.5.1: Output picture of railway track fault detection system
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 56
RAILWAY TRACK SECURITY SYSTEM
FUTURE SCOPE
Here if the crack is dete1cted, then the system is automatically stop, in case of
landmine is detect the system gives buzzer. But we are not sending any crack and mine
location and image anywhere.
By using various sensor network techniques we may also develop more and more
reliable security systems applications in which continuously monitors the railway track
through the sensors and detect any abnormality in the track. We may also send the
latitude and longitude values of crack on the track to the mobile number by using GPS
(Global Positioning System).
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 57
RAILWAY TRACK SECURITY SYSTEM
CONCLUSION
Here, we have presented the rationale, design of our LED-LDR based railway
crack detection scheme. The authors hope that their idea can be implemented in large
scale in the long run to facilitate better safety standards for rail tracks and provide
effective testing infrastructure for achieving better results in the future.
ning System) and GSM (Global system For Mobile) technology.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 58
RAILWAY TRACK SECURITY SYSTEM
REFERENCES
1. K. Vijayakumar, S.R. Wylie, J. D. Cullen, C.C. Wright, A.I. AI- Shamma’a,
“Non
invasive rail track detection system using Microwave sensor”, Journal of App. Phy.,
2009.
2. Qiao Jian-hua; Li Lin-sheng; Zhang Jing-gang; “Design of Rail Surface Crackdetecting System Based on Linear CCD Sensor”, IEEE Int. Conf. on Networking, Sensing
and Control, 2008.
3. Richard J. Greene, John R. Yates and Eann A. Patterson, "Crack detection in rail using
infrared methods", Opt. Eng. 46, 051013, May 2007.
4. Tranverse crack detection in rail head using low frequency eddy currents, Patent
US6768298, www.google.com/patents/US6768298.
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 59
RAILWAY TRACK SECURITY SYSTEM
APPENDIX-A
SOFTWARE CODING
#include <LiquidCrystal.h>
#include<SoftwareSerial.h>
SoftwareSerial mySerial(2,3); // rx,tx
const int buzzer = 13;
const int IR_SENSOR1 = 8;
const int IR_SENSOR2 = 9;
LiquidCrystal lcd(14, 15, 16, 17, 18, 19);
int buttonState1 = 0;
int buttonState2 = 0;
char str1[70];
char *test="$GPGGA";
char logitude[10];
char latitude[10];
int ii,jj,kk;
int temp1;
void setup()
{
// lcd.begin(16,2);
pinMode(IR_SENSOR1, INPUT);
pinMode(IR_SENSOR2, INPUT);
Serial.begin(9600);
mySerial.begin(19200);
pinMode(12, OUTPUT);
pinMode(11, OUTPUT);
pinMode(buzzer, OUTPUT);
digitalWrite(buzzer,LOW);
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 60
RAILWAY TRACK SECURITY SYSTEM
lcd.begin(16,2);
lcd.clear();
lcd.setCursor(0, 0);
lcd.println("LDR LED RAILWAY ");
lcd.setCursor(0, 1);
lcd.println("TRACK FAULT DTCN");
delay(2000);
gps();
delay(1000);
}
void loop()
{
buttonState2 = digitalRead(IR_SENSOR1);
buttonState1 = digitalRead(IR_SENSOR2);
if (buttonState1 == LOW && buttonState2 == HIGH )
{
digitalWrite(buzzer,HIGH);
delay(1000);
lcd.clear();
lcd.setCursor(0,0);
lcd.println("LEFT TRACK FLT ...");
delay(2000);
digitalWrite(buzzer,LOW);
gps();
delay(1000);
SendMessage();
delay(1000);
//
delay(2000);
}
else if (buttonState1 == HIGH && buttonState2 == LOW)
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 61
RAILWAY TRACK SECURITY SYSTEM
{
digitalWrite(buzzer,HIGH);
delay(1000);
lcd.clear();
lcd.setCursor(0,0);
lcd.println("RIGHT TRACK FLT ...");
delay(2000);
digitalWrite(buzzer,LOW);
gps();
delay(1000);
SendMessage();
delay(1000);
//
delay(2000);
}
else if (buttonState1 == LOW && buttonState2 == LOW)
{
digitalWrite(buzzer,HIGH);
delay(1000);
lcd.clear();
lcd.setCursor(0,0);
lcd.println("BOTH TRACK FLT ...");
delay(2000);
digitalWrite(buzzer,LOW);
gps();
delay(1000);
SendMessage();
delay(1000);
// delay(2000);
}
else
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 62
RAILWAY TRACK SECURITY SYSTEM
{
digitalWrite(buzzer,LOW);
lcd.clear();
lcd.setCursor(0,0);
lcd.println("NORMAL....");
delay(10);
}
}
void gps()
{
while (Serial.available()>0)
//Serial incomming data from GPS
{
char inChar2 = (char)Serial.read();
str1[ii]= inChar2;
//store incomming data from GPS to temparary string str[]
ii++;
if (ii < 7)
{
if(str1[ii-1] != test[ii-1])
//check for right string
{
ii=0;
}
}
if(ii >=60)
{
temp1=1;
}
}
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 63
RAILWAY TRACK SECURITY SYSTEM
if (temp1==1)
{
for(ii=18;ii<27;ii++) //18 27
//extract latitude from string
{
latitude[jj]=str1[ii];
jj++;
}
for(ii=31;ii<40;ii++)
//extract longitude from string
{
logitude[kk]=str1[ii];
kk++;
}
lcd.clear();
lcd.setCursor(0,0);
//display latitude and longitude on 16X2 lcd display
lcd.print("Lat:");
lcd.print(latitude);
lcd.setCursor(0,1);
lcd.print("Lon:");
lcd.print(logitude);
delay(100);
temp1=0;
ii=0;
jj=0;
kk=0;
delay(2000);
// next reading within 20 seconds
}
}
void SendMessage()
{
lcd.clear();
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 64
RAILWAY TRACK SECURITY SYSTEM
Serial.println("SENDING A MESSAGE ....please wait......\n");
lcd.print("Sending a Msg...");
mySerial.println("AT+CMGF=1"); //Sets the GSM Module in TextMODE
delay(1000); // Delay of 1000 milli seconds or 1 second
mySerial.println("AT+CMGS=\"+919908184226\"\r");
delay(1000);
// mySerial.println(" CURRENT LOCATION:");// The SMS textyou want to send
// delay(200);
// mySerial.print("Lat:");
// delay(1000);
mySerial.println(latitude);
delay(1000);
mySerial.print(" N ");
delay(1000);
// mySerial.print("Lon:");
// delay(1000);
mySerial.println(logitude);
delay(1000);
mySerial.print(" E");
delay(1000);
mySerial.print((char)26);// ASCII code of CTRL+Z
delay(5000);
delay(200);
Serial.println("MESSAGE SENT ..........");
lcd.clear();
lcd.print("Message Sent.");
delay(200);
}
DEPT. OF E.C.E.,SSN ENGINEERING COLLEGE,ONGOLE
Page 65