A project report onTRACKING SYSTEM USING GSM, GPS & ARM7
Submitted in partial fulfilment of the requirement for the award
of the Degree OfBachelor of Technology from
Guru Gobind Singh Indraprastha UniversityInElectronic &
Communication
Under the guidance of: Submitted by: ASHUTOSH UPADHAYAYMr.
Jagrit : SAMIR BOTHRAAsst. Prof., ECE Department: RASHMI SINGH :
SHIVANSHU GUPTA
HMR Institute of Technology &
ManagementDelhi-1100362011-2015
CERTIFICATE
This is to certify that ASHUTOSH UPADHAYAY, SAMIR BOTHRA, RASHMI
SINGH, SHIVANSHU GUPTA have carried out the project work presented
in this report entitled TRACKING SYSTEM USING GSM, GPS & ARM7
for award of Bachelor of Technology (E.C.E) from GGSIPU, Delhi
under my guidance and supervision. The report embodies the result
of original work and studies are carried out by the students
themselves and the contents of the report do not form basis for
award of any other degree to the candidates or anybody else.
Prof. A. K. Shrivastva Asst. Prof. JagritHead of Department
Project GuideECEECE
ACKNOWLEDGEMENTWith due respect and gratitude we would like to
thank our supervisorAsst. Prof. Jagrit for his constant support,
able guidance and ever following stream of encouragement throughout
this work.
We would also like to thank Ms Yukti who helped us in our
endeavour and all the staff of the Department of Electronics and
Communication Engineering of HMRITM who made working on this
project and completing it an enjoyable job for us.
Date:ASHUTOSH UPADHAYAY (08213302811)SAMIR BOTHRA (06113302811)
RASHMI SINGH (09913302811)SHIVANSHU GUPTA (05096504911)
ABSTRACT
TABLE OF CONTENTSCertificateAcknowledgementTable of ContentsList
of FiguresList of TablesAbbreviationsChapter 1: Introduction to
VTS1.1Introduction1.2Vehicle Security using VTS1.3Active versus
Passive Tracking1.4Types of GPS Vehicle Tracking1.5Typical
Architecture1.6History of Vehicle Tracking1.6.1 Early
Technology1.6.2 New development in technology1.7Vehicle Tracking
System Features1.7.1 Vehicle Tracking Benefits1.8Vehicle Tracing in
IndiaChapter 2: Block Diagram of VTS2.1Block Diagram of Vehicle
Tracing Using GSM and GPS Modem 2.2Hardware Components 2.2.1
GPS2.2.1.1 Working of GPS2.2.1.2 Triangulation2.2.1.3
Augmentation2.2.2 GSM2.2.3 RS232 Interface2.2.3.1 The scope of the
standard2.2.3.2 History of RS 2322.2.3.3 Limitation of
Standard2.2.3.4 Standard details2.2.3.5 Connectors2.2.3.6
Cables2.2.3.7 Conventions2.2.3.8 RTS/CTS handshaking2.2.3.9 3-wire
and 5-wire RS-2322.2.3.10 Seldom used features2.2.3.11 Timing
Signals2.2.3.12 Other Serial interfaces similar to RS-2322.2.4
LCD2.2.4.1 Advantages and Disadvantages
Chapter 3:Working of VTS3.1Schematic Diagram of VTS3.2Circuit
Description3.3Circuit Operation3.3.1 Power3.3.2 Serial
Ports3.4Operating procedureChapter 4:Microcontroller
ARM74.1Features4.2The Pin Configuration4.2.1 Special Function
Registers (SFR)4.3Memory Organization4.4TimersChapter 5:GSM
Module5.1GSM History5.2Services Provided by GSM5.3Mobile
Station5.4Base Station Subsystem5.4.1 Base Station Controller5.5
Architecture of the GSM Network5.6 Radio Link Aspects5.7 Multiple
Access and Channel Structure5.8 Frequency Hopping5.9 Discontinuous
Reception5.10Power Control5.11Network Aspects5.12Radio Resources
Management5.13Handover5.14Mobility Management5.15Location
Updating5.16Authentication and Security5.17Communication
Management5.18Call RoutingChapter 6:GPS Receiver6.1GPS History6.1.1
Working and Operation6.2GPS Data DecodingChapter 7:KEIL Software7.1
Introduction7.2 KEIL uVision47.3 KEIL Software Programing
Procedure7.3.1 Procedure Steps7.4 Applications of KEIL
SoftwareChapter 8:Applications8.1 Applications8.2
LimitationsChapter 9:Result AnalysisChapter 10:Conclusion and
Future ScopeReferences
LIST OF FIGURES
Figure 1.1Vehicle tracking systemFigure 2.1Block diagramFigure
2.2A 25 pin connector as described in the RS-232 standardFigure
2.3Trace of voltage levels for uppercase ASCII "K" characterFigure
2.4Upper Picture: RS232 signalling as seen when probed by an actual
oscilloscopeFigure 2.5A general purpose alphanumeric LCD, with two
lines of characters.Figure 3.1Schematic diagram of vehicle tracing
using GSM and GPSFigure 5.1Mobile station SIM portFigure 5.2Baste
Station Subsystem.Figure 5.3Siemens BSCFigure 5.4Siemens TRAUFigure
5.5General architecture of a GSM networkFigure 5.6Signalling
protocol structure in GSMFigure 5.7Call routing for a mobile
terminating callFigure 6.1G.P.S receivers communicating with the
satelliteFigure 9.1Picture of final VTS kitFigure 9.2Message
received from the VTS kit
LIST OF TABLES
Table 2.1Commonly used RS-232 signals and pin assignmentsTable
2.2Pin assignmentsTable 2.3RS-232 Voltage LevelsTable 2.4TX and RX
pin connection
ABBREVIATIONSVTSVehicle Tracking SystemGSMGlobal System for
Mobile CommunicationGPSGlobal Positioning SystemRIRing
IndicatorTxTransmitterRxReceiverSFRSpecial Function
RegisterLCDLiquid Crystal DisplayRAMRandom Access MemoryROMRead
Only MemoryRS-232 Recommended StandardTTLTransistor Transistor
LogicCMOS Complementary Metal Oxide Semi-ConductorUART Universal
Asynchronous Receiver TransmitterRSTResetALEAddress Latch
EnablePSENProgram Store Enable
CHAPTER 1INTRODUCTION TO VTS
1.1 IntroductionVehicle Tracking System (VTS) is the technology
used to determine the location of a vehicle using different methods
like GPS and other radio navigation systems operating through
satellites and ground based stations. By following triangulation or
trilateration methods the tracking system enables to calculate easy
and accurate location of the vehicle. Vehicle information like
location details, speed, distance travelled etc. can be viewed on a
digital mapping with the help of a software via Internet. Even data
can be stored and downloaded to a computer from the GPS unit at a
base station and that can later be used for analysis. This system
is an important tool for tracking each vehicle at a given period of
time and now it is becoming increasingly popular for people having
expensive cars and hence as a theft prevention and retrieval
device.1. The system consists of modern hardware and software
components enabling one to track their vehicle online or offline.
Any vehicle tracking system consists of mainly three parts mobile
vehicle unit, fixed based station and, database and software
system. 2. Vehicle Unit: It is the hardware component attached to
the vehicle having either a GPS/GSM modem. The unit is configured
around a primary modem that functions with the tracking software by
receiving signals from GPS satellites or radio station points with
the help of antenna. The controller modem converts the data and
sends the vehicle location data to the server. 3. Fixed Based
Station: Consists of a wireless network to receive and forward the
data to the data centre. Base stations are equipped with tracking
software and geographic map useful for determining the vehicle
location. Maps of every city and landmarks are available in the
based station that has an in-built Web Server. 4. Database and
Software: The position information or the coordinates of each
visiting points are stored in a database, which later can be viewed
in a display screen using digital maps. However, the users have to
connect themselves to the web server with the respective vehicle ID
stored in the database and only then s/he can view the location of
vehicle travelled.
1.2 Vehicle Security using VTSVehicle Security is a primary
concern for all vehicle owners. Owners as well as researchers are
always on the lookout for new and improved security systems for
their vehicles. One has to be thankful for the upcoming
technologies, like GPS systems, which enables the owner to closely
monitor and track his vehicle in real-time and also check the
history of vehicles movements. This new technology, popularly
called Vehicle Tracking Systems has done wonders in maintaining the
security of the vehicle tracking system is one of the biggest
technological advancements to track the activities of the vehicle.
The security system uses Global Positioning System GPS, to find the
location of the monitored or tracked vehicle and then uses
satellite or radio systems to send to send the coordinates and the
location data to the monitoring centre. At monitoring centrevarious
softwares are used to plot the Vehicle on a map. In this way the
Vehicle owners are able to track their vehicle on a real-time
basis. Due to real-time tracking facility, vehicle tracking systems
are becoming increasingly popular among owners of expensive
vehicles.The vehicle tracking hardware is fitted on to the vehicle.
It is fitted in such a manner that it is not visible to anyone who
is outside the vehicle. Thus it operates as a covert unit which
continuously sends the location data to the monitoring unit.When
the vehicle is stolen, the location data sent by tracking unit can
be used to find the location and coordinates can be sent to police
for further action. Some Vehicle tracking System can even detect
unauthorized movements of the vehicle and then alert the owner.
This gives an edge over other pieces of technology for the same
purposeMonitoring centre Software helps the vehicle owner with a
view of the location at which the vehicle stands. Browsing is easy
and the owners can make use of any browser and connect to the
monitoring centre software, to find and track his vehicle. This in
turn saves a lot of effort to find the vehicle's position by
replacing the manual call to the driver.As we have seen the vehicle
tracking system is an exciting piece of technology for vehicle
security. It enables the owner to virtually keep an eye on his
vehicle any time and from anywhere in the world.A vehicle tracking
system combines the installation of an electronic device in a
vehicle, or fleet of vehicles, with purpose-designed computer
software at least at one operational base to enable the owner or a
third party to track the vehicle's location, collecting data in the
process from the field and deliver itto the base of operation.
Modern vehicle tracking systems commonly use GPS or GLONASS
technology for locating the vehicle, but other types of automatic
vehicle location technology can also be used. Vehicle information
can be viewed on electronic maps via the Internet or specialized
software. Urban public transit authorities are an increasingly
common user of vehicle tracking systems, particularly in large
cities.Vehicle tracking systems are commonly used by fleet
operators for fleet management functions such as fleet tracking,
routing, dispatch, on-board information and security. Along with
commercial fleet operators, urban transit agencies use the
technology for a number of purposes, including monitoring schedule
adherence of buses in service, triggering changes of buses'
destination sign displays at the end of the line (or other set
location along a bus route), and triggering pre-recorded
announcements for passengers. The American Public Transportation
Association estimated that, at the beginning of 2009, around half
of all transit buses in the United States were already using a
GPS-based vehicle tracking system to trigger automated stop
announcements. This can refer to external announcements (triggered
by the opening of the bus's door) at a bus stop, announcing the
vehicle's route number and destination, primarily for the benefit
of visually impaired customers, or to internal announcements (to
passengers already on board) identifying the next stop, as the bus
(or tram) approaches a stop, or both. Data collected as a transit
vehicle follows its route is often continuously fed into a computer
program which compares the vehicle's actual location and time with
its schedule, and in turn produces a frequently updating display
for the driver, telling him/her how early or late he/she is at any
given time, potentially making it easier to adhere more closely to
the published schedule. Such programs are also used to provide
customers with real-time information as to the waiting time until
arrival of the next bus or tram/streetcar at a given stop, based on
the nearest vehicles' actual progress at the time, rather than
merely giving information as to the scheduled time of the next
arrival. Transit systems providing this kind of information assign
a unique number to each stop, and waiting passengers can obtain
information by entering the stop number into an automated telephone
system or an application on the transit system's website. Some
transit agencies provide a virtual map on their website, with icons
depicting the current locations of buses in service on each route,
for customers' information, while others provide such information
only to dispatchers or other employees.Other applications include
monitoring driving behaviour, such as an employer of an employee,
or a parent with a teen driver.Vehicle tracking systems are also
popular in consumer vehicles as a theft prevention and retrieval
device. Police can simply follow the signal emittedby the tracking
system and locate the stolen vehicle. When used as a security
system, a Vehicle Tracking System may serve as either an addition
to or replacement for a traditional car alarm. Some vehicle
tracking systems make it possible to control vehicle remotely,
including block doors or engine in case of emergency. The existence
of vehicle tracking device then can be used to reduce the insurance
cost, because the loss-risk of the vehicle drops
significantly.Vehicle tracking systems are an integrated part of
the "layered approach" to vehicle protection, recommended by the
National Insurance Crime Bureau (NICB) to prevent motor vehicle
theft. This approach recommends four layers of security based on
the risk factors pertaining to a specific vehicle. Vehicle Tracking
Systems are one such layer, and are described by the NICB as very
effective in helping police recover stolen vehicles.Some vehicle
tracking systems integrate several security systems, for example by
sending an automatic alert to a phone or email if an alarm is
triggered or the vehicle is moved without authorization, or when it
leaves or enters a geofence.1.3 Active versus Passive
TrackingSeveral types of vehicle tracking devices exist. Typically
they are classified as "passive" and "active". "Passive" devices
store GPS location, speed, heading and sometimes a trigger event
such as key on/off, door open/closed. Once the vehicle returns to a
predetermined point, the device is removed and the data downloaded
to a computer for evaluation. Passive systems include auto download
type that transfer data via wireless download. "Active" devices
also collect the same information but usually transmit the data in
real-time via cellular or satellite networks to a computer or data
centre for evaluation.Many modern vehicle tracking devices combine
both active and passive tracking abilities: when a cellular network
is available and a tracking device is connected it transmits data
to a server; when a network is not available the device stores data
in internal memory and will transmit stored data to the server
later when the network becomes available again.Historically vehicle
tracking has been accomplished by installing a box into the
vehicle, either self-powered with a battery or wired into the
vehicle's power system. For detailed vehicle locating and tracking
this is still the predominant method; however, many companies are
increasingly interested in the emerging cell phone technologies
that provide tracking of multiple entities, such as both a
salesperson and their vehicle. These systems also offer tracking of
calls, texts, and Web use and generally provide a wider range of
options.
1.4 Types of GPS Vehicle TrackingThere are three main types of
GPS vehicle tracking, tracking based mobile, wireless passive
tracking and satellite in real-time GPS tracking. This article
discusses the advantages and disadvantages to all three types of
GPS vehicle tracking circumference.
1. Mobile phone based tracking The initial cost for the
construction of the system is slightly lower than the other two
options. With a mobile phone-based tracking average price is about
$ 500. A cell-based monitoring system sends information about when
a vehicle is every five minutes during a rural network. The average
monthly cost is about thirty-five dollars for airtime.
2. Wireless Passive Tracking A big advantage that this type of
tracking system is that there is no monthly fee, so that when the
system was introduced, there will be other costs associated with
it. But setting the scheme is a bit 'expensive. The average is
about $ 700 for hardware and $ 800 for software and databases. With
this type of system, most say that the disadvantage is that
information about where the vehicle is not only can exist when the
vehicle is returned to the base business. This is a great
disadvantage, particularly for companies that are looking for a
monitoring system that tells them where their vehicle will be in
case of theft or an accident. However, many systems are now
introducing wireless modems into theirdevices so that tracking
information can be without memory of the vehicle to be seen. With a
wireless modem that is wireless passive tracking systems are also
able to gather information on how fast the vehicle was traveling,
stopping, and made other detailed information. With this new
addition, many companies believe that this system is perfect,
because there is no monthly bill.
3. Via satellite in real time This type of system provides less
detailed information, but work at the national level, making it a
good choice for shipping and trucking companies. Spending on
construction of the system on average about $ 700. The monthly fees
for this system vary from five dollars for a hundred dollars,
depending on how the implementation of a reporting entity would
be.TechnologyOver the next few years, GPS tracking will be able to
provide businesses with a number of other benefits. Some companies
have already introduced a way for a customer has signed the credit
card and managed at local level through the device. Others are
creating ways for dispatcher to send the information re-routing,
the GPS device directly to a manager. Not a new requirement for GPS
systems is that they will have access to the Internet and store
information about the vehicle as a driver or mechanic GPS device to
see the diagrams used to assist with the vehicle you want to leave.
Beyond that all the information be saved and stored in its
database.
1.5 Typical ArchitectureMajor constituents of the GPS based
tracking are1. GPS tracking device The device fits into the vehicle
and captures the GPS location information apart from other vehicle
information at regular intervals to a central server. The other
vehicle information can include fuel amount, engine temperature,
altitude, reverse geocoding, door open/close, tire pressure, cut
off fuel, turn off ignition, turn on headlight, turn on taillight,
battery status, GSM area code/cell code decoded, number of GPS
satellites in view, glass open/close, fuel amount, emergency button
status, cumulative idling, computed odometer, engine RPM, throttle
position, and a lot more. Capability of these devices actually
decides the final capability of the whole tracking system.2. GPS
tracking server The tracking server has three responsibilities:
receiving data from the GPS tracking unit, securely storing it, and
serving this information on demand to the user.3. User interface
The UI determines how one will be able to access information, view
vehicle data, and elicit important details from it.
1.6 History of Vehicle TrackingGPS or Global Positioning Systems
were designed by the United States Government and military, which
the design was intended to be used as surveillance. After several
years went by the government signed a treaty to allow civilians to
buy GPS units also only the civilians would get precise downgraded
ratings.Years after the Global Positioning Systems were developed
the military controlled the systems despite that civilians could
still purchase them in stores. In addition, despite that Europe has
designed its own systems called the Galileo the US military still
has complete control.GPS units are also called tracking devices
that are quite costly still. As more of these devices develop
however the more affordable the GPS can be purchased. Despite of
the innovative technology and designs of the GPS today the devices
has seen some notable changes or reductions in pricing. Companies
now have more access to these devices and many of the companies can
find benefits.These days you can pay-as-you go or lease a GPS
system for your company. This means you do not have to worry about
spending upfront money, which once stopped companies from
installing the Global positioning systems at one time.Todays GPS
applications have vastly developed as well. It is possible to use
the Global Positioning Systems to design expense reports, create
time sheets, or reduce the costs of fuel consumption. You can also
use the tracking devices to increase efficiency of employee
driving. The GPS unit allows you to create Geo-Fences about a
designated location, which gives you alerts once your driver(s)
passes through. This means you have added security combined with
more powerful customer support for your workers.Todays GPS units
are great tracking devices that help fleet managers stay in control
of their business. The applications in todays GPS units make it
possible to take full control of your company. It is clear that the
tracking devices offer many benefits to companies, since you can
build automated expense reports anytime.GPS units do more than just
allow companies to create reports. These devices also help to put
an end to thieves. According to recent reports, crime is at a high,
which means that car theft is increasing. If you have the right GPS
unit, you can put an end to car thefts because you can lock and
unlock your car anytime you choose.GPS are small tracking devices
that are installed in your car and it will supply you with feedback
data from tracking software that loads from a satellite. This gives
you more control over your vehicles.The chief reason for companies
to install tracking devices is to monitor their mobile workforce. A
preventive measure device allows companies to monitor their
employees activities. Company workers can no longer take your
vehicles to unassigned locations. They will not be able to get away
with unauthorized activities at any time because you can monitor
their every action on a digital screen.The phantom pixel is another
thing some webmasters do to get better rankings. Unfortunately it
will backfire on you since the search engines do not want this to
occur. You see, the phantom pixel is when you might have a 1 pixel
image or an image so small it cannot be seen by the regular eye.
They use the pixel to stuff it with keywords. The search engine can
view it in the code, which is how they know it is there and can
give you better rank for the keywords in theory. Of course since
the search engines dont like this phantom pixel you are instead not
getting anything for the extra keywords except sent to the
bottomless pit.1.6.1 Early TechnologyIn the initial period of
tracking only two radios were used to exchange the information. One
radio was attached to the vehicle while another at base station by
which drivers were enabled to talk to their masters. Fleet operator
could identify the progress through their routes.The technology was
not without its limits. It was restricted by the distance which
became a hurdle in accuracy and better connectivity between driver
and fleet operators. Base station was dependent on the driver for
the information and a huge size fleet could not have been managed
depending on man-power only.The scene of vehicle tracking underwent
a change with the arrival of GPS technology. This reduced the
dependence on man-power. Most of the work of tracking became
electronic. Computers proved a great help in managing a large fleet
of vehicle. This also made the information authentic. As this
technology was available at affordable cost all whether small or
big fleet could take benefit of this technologyBecause of the cheap
accessibility of the device computer tracking facilities has come
to stay and associated with enhanced management. Today eachvehicle
carries tracking unit which is monitored from the base station.
Base station receives the data from the unit.All these facilities
require a heavy investment of capital for the installation of the
infrastructure of tracking system for monitoring and
dispatching.1.6.2 New development in technologyNew system costs
less with increased efficiency. Presently it is small tracking unit
in the vehicle with web-based interface, connected through a mobile
phone. This device avoids unnecessary investment in infrastructure
with the facility of monitoring from anywhere for the fleet
managers. This provides more efficient route plan to fleet
operators of all sizes and compositions saving money and
time.Vehicle tracking system heralded a new era of convenience and
affordability in fleet management. Thus due to its easy
availability it is going to stay for long.
1.7 Vehicle Tracking System FeaturesMonitoring and managing the
mobile assets are very important for any company dealing with the
services, delivery or transport vehicles. Information technologies
help in supporting these functionalities from remote locations and
update the managers with the latest information of their mobile
assets. Tracking the mobile assets locations data and analysing the
information is necessary for optimal utilization of the
assets.Vehicle Tracking System is a software & hardware system
enabling the vehicle owner to track the position of their vehicle.
A vehicle tracking system uses either GPS or radio technology to
automatically track and record a fleet's field activities. Activity
is recorded by modules attached to each vehicle. And then the data
is transmitted to a central, internet-connected computer where it
is stored. Once the data is transmitted to the computer, it can be
analysed and reports can be downloaded in real-time to your
computer using either web browser based tools or customized
software.1.7.1 Vehicle Tracking BenefitsAn enterprise-level vehicle
tracking system should offer customizable reporting tools, for
example to provide a summary of the any day activities. It should
have the ability to produce and print detailed maps and reports
displaying actual stops, customer locations, mileage travelled, and
elapsed time at each location, and real-time access to vehicle
tracking data and reports. Vehicle tracking system can be active,
passive or both depending upon the application. Here are steps
involved in the vehicle tracking:1. Data capture: Data capturing is
the first step in tacking your vehicle. Data in a vehicle tracking
system is captured through a unit called automated vehicle unit.
The automated vehicle unit uses the Global Positioning System (GPS)
to determine the location of the vehicle. This unit is installed in
the vehicle and contains interfaces to various data sources. This
paper considers the location data capture along with data from
various sensors like fuel, vehicle diagnostic sensors etc. 2. Data
storage: Captured data is stored in the memory of the automated
vehicle unit. 3. Data transfer: Stored data are transferred to the
computer server using the mobile network or by connecting the
vehicle mount unit to the computer. 4. Data analysis: Data analysis
is done through software application. A GIS mapping component is
also an integral part of the vehicle tracking system and it is used
to display the correct location of the vehicle on the map.
1.8Vehicle Tracing in India Vehicle tracking system in India is
mainly used in transport industry that keeps a real-time track of
all vehicles in the fleet. The tracking system consists of GPS
device that brings together GPS and GSM technology using tracking
software. The attached GPS unit in the vehicle sends periodic
updates of its location to the route station through the server of
the cellular network that can be displayed on a digital map. The
location details are later transferred to users via SMS, e-mail or
other form of data transfers.There are various GPS software and
hardware developing companies in India working for tracking
solutions. However, its application is not that much of popular as
in other countries like USA, which regulates the whole GPS network.
In India it is mostly used in Indian transport and logistics
industry and not much personal vehicle tracking.But with better
awareness and promotion the market will increase. Lets have a look
at its current application in India using vehicle tracking though
in less volume.a) Freight forwardingLogistic service providers are
now increasingly adopting vehicle-tracking system for better fleet
management and timely service. The system can continuously monitor
shipment location and so can direct the drivers directly in case of
any change of plan. Fleet managers can keep an eye on all
activities of workers, vehicle over speed, route deviation etc. The
driver in turn can access emergency service in case of sickness,
accident or vehicle breakdown. All in turn supports money and time
management, resulting better customer service.b) Call centresIn
commercial vehicle segments the taxi operators of various call
centres are now using vehicle tracking system for better
information access. However, its application is in its infant stage
in India and if adequate steps are taken in bringing the cost of
hardware and software low then it can be used for tracking personal
vehicle, farming (tractor), tourist buses, security and emergency
vehicle etc. Again Government needs to cut down the restriction
imposed upon the availability of digital maps for commercial use
and this will encourage software industry in developing
cost-effective tracking solutions. Though, sales of both commercial
and passenger vehicles are growing but price of tracking service is
very high and this is the key issue in Indian market. Hence, its
important for market participants to reduce prices of GPS chips and
other products in order to attract more and more users.As far as
Indian vehicle tracking and navigation market is concerned the
recent association of India with Russian Global Navigation
Satellite System (GLONASS) will act as a catalyst in the
improvement of vehicle tracking system. This will give an advantage
in managing traffic, roadways and ports and also as an important
tool for police and security agency to track stolen vehicles.
Hence, in near future there is large prospect for the utility of
vehicle tracking system in India, which can revolutionize the way
we are communicating.
CHAPTER 2Block Diagram Of VTS
2.1 Block Diagram of Vehicle Tracing Using GSM and GPS Modem
2.2 Hardware Components ARM7GPS MODULE GSM MODULE RS232 LCDIn
this project ARM7 microcontroller is used for interfacing to
various hardware peripherals. The current design is an embedded
application, which will continuously monitor a moving Vehicle and
report the status of the Vehicle on reset. For doing so an ARM7
microcontroller is interfaced serially to a GSM Modem and GPS
Receiver. A GSM modem is used to send the position (Latitude and
Longitude) of the vehicle from a remote place. The GPS modem will
continuously give the data i.e. the latitude and longitude
indicating the position of the vehicle. The GPS modem gives many
parameters as the output, but only the needed data coming out is
read and displayed on to the LCD. The same data is sent to the
mobile at the other end from where the position of the vehicle is
demanded. The hardware interfaces to microcontroller are LCD
display, GSM modem and GPS Receiver. The design uses RS-232
protocol for serial communication between the modems and the
microcontroller. When the request by user is sent to the number at
the modem, the system automatically sends a return reply to that
mobile indicating the position of the vehicle in terms of latitude
and longitude.As the Micro Controller, GPS and GSM take a sight of
in depth knowledge, they are explained in the next chapters.2.2.1
GPSGPS, in full Global Positioning System, space-based
radio-navigation system that broadcasts highly accurate navigation
pulses to users on or near the Earth. In the United States Navstar
GPS, 24 main satellites in 6 orbits circle the Earth every 12
hours. In addition, Russia maintains a constellation called GLONASS
(Global Navigation Satellite System).2.2.1.1 Working of GPSGPS
receiver works on 9600 baud rate is used to receive the data from
space Segment (from Satellites), the GPS values of different
Satellites are sent to microcontroller AT89S52, where these are
processed and forwarded to GSM. At the time of processing GPS
receives only $GPRMC values only. From these values microcontroller
takes only latitude and longitude values excluding time, altitude,
name of the satellite, authentication etc. E.g. LAT: 1728:2470 LOG:
7843.3089 GSM modem with a baud rate 57600.A GPS receiver operated
by a user on Earth measures the time it takes radio signals to
travel from four or more satellites to its location, calculates the
distance to each satellite, and from this calculation determines
the users longitude, latitude, and altitude. The U.S. Department of
Defence originally developed the Navstar constellation for military
use, but a less precise form of the service is available free of
charge to civilian users around the globe. The basic civilian
service will locate a receiver within 10 meters (33 feet) of its
true location, though various augmentation techniques can be used
to pinpoint the location within less than 1 cm (0.4 inch). With
such accuracy and the ubiquity of the service, GPS has evolved far
beyond its original military purpose and has created a revolution
in personal and commercial navigation. Battlefield missiles and
artillery projectiles use GPS signals to determine their positions
and velocities, but so do the U.S. space shuttle and the
International Space Station as well as commercial jetliners and
private airplanes. Ambulance fleets, family automobiles, and
railroad locomotives benefit from GPS positioning, which also
serves farm tractors, ocean liners, hikers, and even golfers. Many
GPS receivers are no larger than a pocket calculator and are
powered by disposable batteries, while GPS computer chips the size
of a babys fingernail have been installed in wristwatches, cellular
telephones, and personal digital assistants.2.2.1.2
TriangulationThe principle behind the unprecedented navigational
capabilities of GPS is triangulation. To triangulate, a GPS
receiver precisely measures the time it takes for a satellite
signal to make its brief journey to Earthless than a tenth of a
second. Then it multiplies that time by the speed of a radio
wave300,000 km (186,000 miles) per secondto obtain the
corresponding distance between it and the satellite. This puts the
receiver somewhere on the surface of an imaginary sphere with a
radius equal to its distance from the satellite. When signals from
three other satellites are similarly processed, the receivers
built-in computer calculates the point at which all four spheres
intersect, effectively determining the users current longitude,
latitude, and altitude. (In theory, three satellites would normally
provide an unambiguous three-dimensional fix, but in practice at
least four are used to offset inaccuracy in the receivers clock.)
In addition, the receiver calculates current velocity (speed and
direction) by measuring the instantaneous Doppler Effect shifts
created by the combined motion of the same four satellites.2.2.1.3
AugmentationAlthough the travel time of a satellite signal to Earth
is only a fraction of a second, much can happen to it in that
interval. For example, electrically charged particles in the
ionosphere and density variations in the troposphere may act to
slow and distort satellite signals. These influences can translate
into positional errors for GPS usersa problem that can be
compounded by timing errors in GPS receiver clocks. Further errors
may be introduced by relativistic time dilations, a phenomenon in
which a satellites clock and a receivers clock, located in
different gravitational fields and traveling at different
velocities, tick at different rates. Finally, the single greatest
source of error to users of the Navstar system is the lower
accuracy of the civilian C/A-code pulse. However, various
augmentation methods exist for improving the accuracy of both the
military and the civilian systems.When positional information is
required with pinpoint precision, users can take advantage of
differential GPS techniques. Differential navigation employs a
stationary base station that sits at a known position on the ground
and continuously monitors the signals being broadcast by GPS
satellites in its view. It then computes and broadcasts real-time
navigation corrections to nearby roving receivers. Each roving
receiver, in effect, subtracts its position solution from the base
stations solution, thus eliminating any statistical errors common
to the two. The U.S. Coast Guard maintains a network of such base
stations and transmits corrections over radio beacons covering most
of the United States. Other differential corrections are encoded
within the normal broadcasts of commercial radio stations. Farmers
receiving these broadcasts have been able to direct their field
equipment with great accuracy, making precision farming a common
term in agriculture.Another GPS augmentation technique uses the
carrier waves that convey the satellites navigation pulses to
Earth. Because the length of the carrier wave is more than 1,000
times shorter than the basic navigation pulses, this carrier-aided
approach, under the right circumstances, can reduce navigation
errors to less than 1 cm (0.4 inch). The dramatically improved
accuracy stems primarily from the shorter length and much greater
numbers of carrier waves impinging on the receivers antenna each
second.Yet another augmentation technique is known as
geosynchronous overlays. Geosynchronous overlays employ GPS
payloads piggybacked aboard commercial communication satellites
that are placed in geostationary orbit some 35,000 km (22,000
miles) above the Earth. These relatively small payloads broadcast
civilian C/A-code pulse trains to ground-based users. The U.S.
government is enlarging the Navstar constellation with
geosynchronous overlays to achieve improved coverage, accuracy, and
survivability. Both the European Union and Japan are installing
their own geosynchronous overlays.
2.2.2 GSMGSM (or Global System for Mobile Communications) was
developed in 1990. The first GSM operator has subscribers in 1991,
the beginning of 1994 the network based on the standard, already
had 1.3 million subscribers, and the end of 1995 their number had
increased to 10 million!There were first generation mobile phones
in the 70's, there are 2nd generation mobile phones in the 80's and
90's, and now there are 3rd gen phones which are about to enter the
Indian market. GSM is called a 2nd generation, or 2G communications
technology.In this project it acts as a SMS Receiver and SMS
sender. The GSM technical specifications define the different
entities that form the GSM network by defining their functions and
interface requirements.
2.2.3 RS232 InterfaceIn telecommunications, RS-232 is the
traditional name for a series of standards for serial binary
single-ended data and control signals connecting between a DTE
(Data Terminal Equipment) and a DCE (Data Circuit-terminating
Equipment). It is commonly used in computer serial ports. The
standard defines the electrical characteristics and timing of
signals, the meaning of signals, and the physical size and pin out
of connectors. The current version of the standard is TIA-232-F
Interface between Data Terminal Equipment and Data
Circuit-Terminating Equipment Employing Serial Binary Data
Interchange, issued in 1997.An RS-232 port was once a standard
feature of a personal computer for connections to modems, printers,
mice, data storage, un-interruptible power supplies, and other
peripheral devices. However, the limited transmission speed,
relatively large voltage swing, and large standard connectors
motivated development of the universal serial bus which has
displaced RS-232 from most of its peripheral interface roles. Many
modern personal computers have no RS-232 ports and must use an
external converter to connect to older peripherals. Some RS-232
devices are still found especially in industrial machines or
scientific instruments.2.2.3.1 The scope of the standardThe
Electronic Industries Association (EIA) standard RS-232-C as of
1969 defines:1. Electrical signal characteristics such as voltage
levels, signalling rate, timing and slew-rate of signals voltage
withstand level, short-circuit behaviour, and maximum load
capacitance.2. Interface mechanical characteristics, pluggable
connectors and pin identification.3. Functions of each circuit in
the interface connector. 4. Standard subsets of interface circuits
for selected telecom applications. The standard does not define
such elements as the characterencoding or the framing of
characters, or error detection protocols. The standard does not
define bit rates for transmission, except that it says it is
intended for bit rates lower than 20,000 bits per second. Many
modern devices support speeds of 115,200 bit/s and above. RS 232
makes no provision for power to peripheral devices.Details of
character format and transmission bit rate are controlled by the
serial port hardware, often a single integrated circuit called a
UART that converts data from parallel to asynchronous start-stop
serial form. Details of voltage levels, slew rate, and
short-circuit behaviour are typically controlled by a line driver
that converts from the UART's logic levels to RS-232 compatible
signal levels, and a receiver that converts from RS-232 compatible
signal levels to the UART's logic levels.2.2.3.2 History of RS
232RS-232 was first introduced in 1962. The original DTEs were
electromechanical teletypewriters, and the original DCEs were
(usually) modems. When electronic terminals (smart and dumb) began
to be used, they were often designed to be interchangeable with
teletypewriters, and so supported RS-232. The C revision of the
standard was issued in 1969 in part to accommodate the electrical
characteristics of these devices.Since application to devices such
as computers, printers, test instruments, and so on was not
considered by the standard, designers implementing an RS-232
compatible interface on their equipment often interpreted the
requirements idiosyncratically. Common problems were non-standard
pin assignment of circuits on connectors, and incorrect or missing
control signals. The lack of adherence to the standards produced a
thriving industry of breakout boxes, patch boxes, test equipment,
books, and other aids for the connection of disparate equipment. A
common deviation from the standard was to drive the signals at a
reduced voltage. Some manufacturers therefore built transmitters
that supplied +5V and -5V and labelled them as "RS-232
compatible".Later personal computers (and other devices) started to
make use of the standard so that they could connect to existing
equipment. For many years, an RS-232-compatible port was a standard
feature for serial communications, such as modem connections, on
many computers. It remained in widespread use into the late 1990s.
In personal computer peripherals, it has largely been supplanted by
other interface standards, such as USB. RS-232 is still used to
connect older designs of peripherals, industrial equipment (such as
PLCs), console ports, and special purpose equipment, such as a cash
drawer for a cash register.The standard has been renamed several
times during its history as the sponsoring organization changed its
name, and has been variously known as EIA RS-232, EIA 232, and most
recently as TIA 232. The standard continued to be revised and
updated by the Electronic Industries Alliance and since 1988 by the
Telecommunications Industry Association (TIA) .[3] Revision C was
issued in a document dated August 1969. Revision D was issued in
1986. The current revision is TIA-232-F Interface between Data
Terminal Equipment and Data Circuit-Terminating Equipment Employing
Serial Binary Data Interchange, issued in 1997. Changes since
Revision C have been in timing and details intended to improve
harmonization with the CCITT standard V.24, but equipment built to
the current standard will interoperate with older versions.Related
ITU-T standards include V.24 (circuit identification) and V.28
(signal voltage and timing characteristics).2.2.3.3 Limitation of
StandardBecause the application of RS-232 has extended far beyond
the original purpose of interconnecting a terminal with a modem,
successor standards have been developed to address the
limitations.Issues with the RS-232 standard include:1. The large
voltage swings and requirement for positive and negative supplies
increases power consumption of the interface and complicates power
supply design. The voltage swing requirement also limits the upper
speed of a compatible interface.2. Single-ended signalling referred
to a common signal ground limits the noise immunity and
transmission distance. 3. Multi-drop connection among more than two
devices is not defined. While multi-drop "work-around" has been
devised, they have limitations in speed and compatibility. 4.
Asymmetrical definitions of the two ends of the link make the
assignment of the role of a newly developed device problematic; the
designer must decide on either a DTE-like or DCE-like interface and
which connector pin assignments to use.5. The handshaking and
control lines of the interface are intended for the setup and
takedown of a dial-up communication circuit; in particular, the use
of handshake lines for flow control is not reliably implemented in
many devices.6. No method is specified for sending power to a
device. While a small amount of current can be extracted from the
DTR and RTS lines, this is only suitable for low power devices such
as mice.7. The 25-way connector recommended in the standard is
large compared to current practice.2.2.3.4 Standard detailsIn
RS-232, user data is sent as a time-series of bits. Both
synchronous and asynchronous transmissions are supported by the
standard. In addition to the data circuits, the standard defines a
number of control circuits used to manage the connection between
the DTE and DCE. Each data or control circuit only operates in one
direction that is, signalling from a DTE to the attached DCE or the
reverse. Since transmit data and receive data are separate
circuits, the interface can operate in a full duplex manner,
supporting concurrent data flow in both directions. The standard
does not define character framing within the data stream, or
character encoding.This is typical for start-stop communications,
but the standard does not dictate a character format or bit
order.The RS-232 standard defines the voltage levels that
correspond to logical one and logical zero levels for the data
transmission and the control signal lines. Valid signals are plus
or minus 3 to 15 volts; the 3 V range near zero volts is not a
valid RS-232 level.The standard specifies a maximum open-circuit
voltage of 25 volts: signal levels of 5 V, 10 V, 12 V, and 15 V are
all commonly seen depending on the power supplies available within
a device. RS-232 drivers and receivers must be able to withstand
indefinite short circuit to ground or to any voltage level up to 25
volts. The slew rate, or how fast the signal changes between
levels, is also controlled.For data transmission lines (TxD, RxD
and their secondary channel equivalents) logic one is defined as a
negative voltage, the signal condition is called marking, and has
the functional significance. Logic zero is positive and the signal
condition is termed spacing. Control signals are logically inverted
with respect to what one sees on the data transmission lines. When
one of these signals is active, the voltage on the line will be
between +3 to +15 volts. The inactive state for these signals is
the opposite voltage condition, between 3 and 15 volts. Examples of
control lines include request to send (RTS), clear to send (CTS),
data terminal ready (DTR), and data set ready (DSR).Because the
voltage levels are higher than logic levels typically used by
integrated circuits, special intervening driver circuits are
required to translate logic levels. These also protect the device's
internal circuitry from short circuits or transients that may
appear on the RS-232 interface, and provide sufficient current to
comply with the slew rate requirements for data
transmission.Because both ends of the RS-232 circuit depend on the
ground pin being zero volts, problems will occur when connecting
machinery and computers where the voltage between the ground pin on
one end and the ground pin on the other is not zero. This may also
cause a hazardous ground loop. Use of a common ground limits RS-232
to applications with relatively short cables. If the two devices
are far enough apart or on separate power systems, the local ground
connections at either end of the cable will have differing
voltages; this difference will reduce the noise margin of the
signals. Balanced, differential, serial connections such as USB,
RS-422 and RS-485 can tolerate larger ground voltage differences
because of the differential signalling.Unused interface signals
terminated to ground will have an undefined logic state. Where it
is necessary to permanently set a control signal to a defined
state, it must be connected to a voltage source that asserts the
logic 1 or logic 0 level. Some devices provide test voltages on
their interface connectors for this purpose.2.2.3.5
ConnectorsRS-232 devices may be classified as Data Terminal
Equipment (DTE) or Data Communication Equipment (DCE); this defines
at each device which wires will be sending and receiving each
signal. The standard recommended but did not make mandatory the
D-subminiature 25 pin connector. In general and according to the
standard, terminals and computers have male connectors with DTE pin
functions, and modems have female connectors with DCE pin
functions. Other devices may have any combination of connector
gender and pin definitions. Many terminals were manufactured with
female terminals but were sold with a cable with male connectors at
each end; the terminal with its cable satisfied the recommendations
in the standard.Presence of a 25 pin D-sub connector does not
necessarily indicate an RS-232-C compliant interface. For example,
on the original IBM PC, a male D-sub was an RS-232-C DTE port (with
a non-standard current loop interface on reserved pins), but the
female D-sub connector was used for a parallel Centroids printer
port. Some personal computers put non-standard voltages or signals
on some pins of their serial ports. The standard specifies 20
different signal connections. Since most devices use only a few
signals, smaller connectors can often be used.The signals are named
from the standpoint of the DTE. The ground signal is a common
return for the other connections. The DB-25 connector includes a
second "protective ground" on pin 1.Data can be sent over a
secondary channel (when implemented by the DTE and DCE devices),
which is equivalent to the primary channel. Pin assignments are
described in shown in Table 2.2:Table 2.1. Commonly used RS-232
signals and pin assignmentsSignalOrigin DB-25 pin
NameTypical purposeAbbreviationDTEDCE
DataIndicates presence ofDTR20
Terminal ReadyDTE to DCE.
DataDCE is connected to theDCD8
Carrier Detecttelephone line.
Data Set ReadyDCE is ready to receiveDSR6
commands or data.
DCE hasdetectedan
Ring Indicatorincomingring signalonRI22
the telephone line.
Request ToDTE requests the DCERTS4
Sendprepare to receive data.
Clear To SendIndicates DCE is ready toCTS5
accept data.
TransmittedCarries data from DTE toTxD2
DataDCE.
Received DataCarries data from DCE toRxD3
DTE.
CommonGNDcommon7
Ground
ProtectivePGcommon1
Ground
Table 2.2 Pin assignmentsSignalPin
Common Ground7 (same as primary)
Secondary Transmitted Data (STD)14
Secondary Received Data (SRD)16
Secondary Request To Send (SRTS)19
Secondary Clear To Send (SCTS)13
Secondary Carrier Detect (SDCD)12
Ring Indicator' (RI), is a signal sent from the modem to the
terminal device. It indicates to the terminal device that the phone
line is ringing. In many computer serial ports, a hardware
interrupt is generated when the RI signal changes state. Having
support for this hardware interrupt means that a program or
operating system can be informed of a change in state of the RI
pin, without requiring the software to constantly "poll" the state
of the pin. RI is a one-way signal from the modem to the terminal
(or more generally, the DCE to the DTE) that does not correspond to
another signal that carries similar information the opposite way.On
an external modem the status of the Ring Indicator pin is often
coupled to the "AA" (auto answer) light, which flashes if the RI
signal has detected a ring. The asserted RI signal follows the
ringing pattern closely,which can permit software to detect
distinctive ring patterns.The Ring Indicator signal is used by some
older uninterruptible power supplies (UPS's) to signal a power
failure state to the computer.Certain personal computers can be
configured for wake-on-ring, allowing a computer that is suspended
to answer a phone call.2.2.3.6 CablesThe standard does not define a
maximum cable length but instead defines the maximum capacitance
that a compliant drive circuit must tolerate. A widely used rule of
thumb indicates that cables more than 50 feet (15 m) long will have
too much capacitance, unless special cables are used. By using
low-capacitance cables, full speed communication can be maintained
over larger distances up to about 1,000 feet (300 m) .[8] For
longer distances, other signal standards are better suited to
maintain high speed.Since the standard definitions are not always
correctly applied, it is often necessary to consult documentation,
test connections with a breakout box, or use trial and error to
find a cable that works when interconnecting two devices.
Connecting a fully standard-compliant DCE device and DTE device
would use a cable that connects identical pin numbers in each
connector (a so-called "straight cable"). "Gender changers" are
available to solve gender mismatches between cables and connectors.
Connecting devices with different types of connectors requires a
cable that connects the corresponding pins according to the table
above. Cables with 9 pins on one end and 25 on the other are
common. Manufacturers of equipment with 8P8C connectors usually
provide a cable with either a DB-25 or DE-9 connector (or sometimes
interchangeable connectors so they can work with multiple devices).
Poor-quality cables can cause false signals by crosstalk between
data and control lines (such as Ring Indicator). If a given cable
will not allow a data connection, especially if a Gender changer is
in use, a Null modem may be necessary.2.2.3.7 ConventionsFor
functional communication through a serial port interface,
conventions of bit rate, character framing, communications
protocol, character encoding, data compression, and error
detection, not defined in RS 232, must be agreed to by both sending
and receiving equipment. For example, consider the serial ports of
the original IBM PC. This implementation used an 8250 UART using
asynchronous start-stop character formatting with 7 or 8 data bits
per frame, usually ASCII character coding, and data rates
programmable between 75 bits per second and 115,200 bits per
second. Data rates above 20,000 bits per second are out of the
scope of the standard, although higher data rates are sometimes
used by commercially manufactured equipment. Since most RS-232
devices do not have automatic baud rate detection, users must
manually set the baud rate (and all other parameters) at both ends
of the RS-232 connection.
In the particular case of the IBM PC, as with most UART chips
including the 8250 UART used by the IBM PC, baud rates were
programmable with arbitrary values. This allowed a PC to be
connected to devices not using the rates typically used with
modems. Not all baud rates can be programmed, due to the clock
frequency of the 8250 UART in the PC, and the granularity of the
baud rate setting. This includes the baud rate of MIDI, 31,250 bits
per second, which is generally not achievable by a standard IBM PC
serial port. MIDI-to-RS-232 interfaces designed for the IBM PC
include baud rate translation hardware to adjust the baud rate of
the MIDI data to something that the IBM PC can support, for example
19,200 or 38,400 bits per second.2.2.3.8 RTS/CTS handshakingIn
older versions of the specification, RS-232's use of the RTS and
CTS lines is asymmetric: The DTE asserts RTS to indicate a desire
to transmit to the DCE, and the DCE asserts CTS in response to
grant permission. This allows for half-duplex modems that disable
their transmitters when not required, and must transmit a
synchronization preamble to the receiver when they are re-enabled.
This scheme is also employed on present-day RS-232 to RS-485
converters, where the RS-232's RTS signal is used to ask the
converter to take control of the RS-485 bus - a concept that does
not otherwise exist in RS-232. There is no way for the DTE to
indicate that it is unable to accept data from the DCE.A
non-standard symmetric alternative, commonly called "RTS/CTS
handshaking," was developed by various equipment manufacturers. In
this scheme, CTS is no longer a response to RTS; instead, CTS
indicates permission from the DCE for the DTE to send data to the
DCE, and RTS indicates permission from the DTE for the DCE to send
data to the DTE. RTS and CTS are controlled by the DTE and DCE
respectively, each independent of the other. This was eventually
codified in version RS-232-E (actually TIA-232-E by that time) by
defining a new signal, "RTR (Ready to Receive)," which is CCITT
V.24 circuit 133. TIA-232-E and the corresponding international
standards were updated to show that circuit 133, when implemented,
shares the same pin as RTS (Request to Send), and that when 133 is
in use, RTS is assumed by the DCE to be ON at all times.Thus, with
this alternative usage, one can think of RTS asserted (positive
voltage, logic 0) meaning that the DTE is indicating it is "ready
to receive" from the DCE, rather than requesting permission from
the DCE to send characters to the DCE.Note that equipment using
this protocol must be prepared to buffer some extra data, since a
transmission may have begun just before the control line state
change.RTS/CTS handshaking is an example of hardware flow control.
However, "hardware flow control" in the description of the options
available on an RS-232-equipped device does not always mean RTS/CTS
handshaking.2.2.3.9 3-wire and 5-wire RS-232Minimal 3-wire RS-232
connections consisting only of transmit data, receive data, and
ground, is commonly used when the full facilities of RS-232 are not
required. Even a two-wire connection (data and ground) can be used
if the data flow is one way (for example, a digital postal scale
that periodically sends a weight reading, or a GPS receiver that
periodically sends position, if no configuration via RS-232 is
necessary). When only hardware flow control is required in addition
to two-way data, the RTS and CTS lines are added in a 5-wire
version.2.2.3.10 Seldom used featuresThe EIA-232 standard specifies
connections for several features that are not used in most
implementations. Their use requires the 25-pin connectors and
cables, and of course both the DTE and DCE must support them.a)
Signal rate selectionThe DTE or DCE can specify use of a "high" or
"low" signallingrate. The rates as well as which device will select
the rate must be configured in both the DTE and DCE. The
prearranged device selects the high rate by setting pin 23 to ON.b)
Loopback testingMany DCE devices have a loopback capability used
for testing. When enabled, signals are echoed back to the sender
rather than being sent on to the receiver. If supported, the DTE
can signal the local DCE (the one it is connected to) to enter
loopback mode by setting pin 18 to ON, or the remote DCE (the one
the local DCE is connected to) to enter loopback mode by setting
pin 21 to ON. The latter tests the communications link as well as
both DCE's. When the DCE is in test mode it signals the DTE by
setting pin 25 to ON.A commonly used version of loopback testing
does not involve any special capability of either end. A hardware
loopback is simply a wire connecting complementary pins together in
the same connectorLoopback testing is often performed with a
specialized DTE called a bit error rate tester (or BERT).2.2.3.11
Timing SignalsSome synchronous devices provide a clock signal to
synchronize data transmission, especially at higher data rates. Two
timing signals are provided by the DCE on pins 15 and 17. Pin 15 is
the transmitter clock, or send timing (ST); the DTE puts the next
bit on the data line (pin 2) when this clock transitions from OFF
to ON (so it is stable during the ON to OFF transition when the DCE
registers the bit). Pin 17 is the receiver clock, or receive timing
(RT); the DTE reads the next bit from the data line (pin 3) when
this clock transitions from ON to OFF.Alternatively, the DTE can
provide a clock signal, called transmitter timing (TT), on pin 24
for transmitted data. Data is changed when the clock transitions
from OFF to ON and read during the ON to OFF transition. TT can be
used to overcome the issue where ST must traverse a cable of
unknown length and delay, clock a bit out of the DTE after another
unknown delay, and return it to the DCE over the same unknown cable
delay. Since the relation between the transmitted bit and TT can be
fixed in the DTE design, and since both signals traverse the same
cable length, using TT eliminates the issue. TT may be generated by
looping ST back with an appropriate phase change to align it with
the transmitted data. ST loop back to TT lets the DTE use the DCE
as the frequency reference, and correct the clock to data
timing.2.2.3.12 Other Serial interfaces similar to RS-2321. RS-422
(a high-speed system similar to RS-232 but with
differentialsignalling)2. RS-423 (a high-speed system similar to
RS-422 but with unbalancedsignalling) 3. RS-449 (a functional and
mechanical interface that used RS-422 and RS-423 signals - it never
caught on like RS-232 and was withdrawn by the EIA)4. RS-485 (a
descendant of RS-422 that can be used as a bus in multidrop
configurations) 5. MIL-STD-188 (a system like RS-232 but with
better impedance and rise time control) 6. EIA-530 (a high-speed
system using RS-422 or RS-423 electrical properties in an EIA-232
pinout configuration, thus combining the best of both; supersedes
RS-449) 7. EIA/TIA-561 8 Position Non-Synchronous Interface
betweenData Terminal Equipment and Data Circuit Terminating
Equipment Employing Serial Binary Data Interchange 8. EIA/TIA-562
Electrical Characteristics for an Unbalanced Digital Interface
(low-voltage version of EIA/TIA-232) 9. TIA-574 (standardizes the
9-pin D-subminiature connector pinout for use with EIA-232
electrical signalling, as originated on the IBM PC/AT)10.SpaceWire
(high-speed serial system designed for use on board
spacecraft).2.2.6 LCDA liquid crystal display (LCD) is a flat panel
display, electronic visual display, or video display that uses the
light modulating properties of liquid crystals (LCs). LCs does not
emit light directly.LCDs are used in a wide range of applications,
including computer monitors,television, instrument panels, aircraft
cockpit displays, signage, etc. They are common in consumer devices
such as video players, gaming devices, clocks, watches,
calculators, andtelephones. LCDs have replaced cathode ray tube
(CRT) displays in most applications. They are available in a wider
range of screen sizes than CRT and plasma displays, and since they
do not use phosphors, they cannot suffer image burn-in. LCDs are,
however, susceptible to image persistence.LCDs are more energy
efficient and offer safer disposal than CRTs. Its low electrical
power consumption enables it to be used in battery-powered
electronic equipment. It is an electronically modulated optical
device made up of any number of segments filledwith liquid crystals
and arrayed in front of a light source (backlight) or reflector to
produce images in colour or monochrome.The mostflexible ones use an
array of small pixels. The earliest discovery leading to the
development of LCD technology, the discovery of liquid crystals,
dates from 1888. By 2008, worldwide sales of televisions with LCD
screens had surpassed the sale of CRT units. Following figure is a
16x2 LCD.Monochrome passive-matrix LCDs were standard in most early
laptops (although a few used plasma displays) and the original
Nintendo GameBoy until the mid-1990s, when colour active-matrix
became standard on all laptops. The commercially unsuccessful
Macintosh Portable (released in 1989) was one of the first to use
an active-matrix display (though still monochrome).Passive-matrix
LCDs are still used today for applications less demanding than
laptops and TVs. In particular, portable devices with less
information content to be displayed, where lowest power consumption
(no backlight), low cost and/or readability in direct sunlight are
needed, use this type of display.2.2.6.1 Advantages and
DisadvantagesIn spite of LCDs being a well proven and still viable
technology, as display devices LCDs are not perfect for all
applications.Advantages1. Very compact and light. 2. Low power
consumption. 3. No geometric distortion. 4. Little or no flicker
depending on backlight technology.5. Not affected by screen
burn-in. 6. Can be made in almost any size or shape. 7. No
theoretical resolution limit. Disadvantages1. Limited viewing
angle, causing colour, saturation, contrast and brightness to vary,
even within the intended viewing angle, by variations in posture.2.
Bleeding and uneven backlighting in some monitors, causing
brightness distortion, especially toward the edges. 3. Smearing and
ghosting artefacts caused by slow response times (>8 ms) and
"sample and hold" operation. 4. Fixed bit depth, many cheaper LCDs
are only able to display 262,000 colours. 8-bit S-IPS panels can
display 16 million colours and have significantly better black
level, but are expensive and have slower response time. 5. Low bit
depth results in images with unnatural or excessive contrast.6.
Input lag 7. Dead or stuck pixels may occur during manufacturing or
through use.
CHAPTER 3WORKING OF VTS
3.1 Schematic Diagram of VTS
3.2 Circuit DescriptionThe hardware interfaces to
microcontroller are LCD display, GSM modem and GPS receiver. The
design uses RS-232 protocol for serial communication between the
modems and the microcontroller. A serial driver IC is used for
converting TTL voltage levels to RS-232 voltage levels.When the
reset is sent by the number at the modem, the system automatically
sends a return reply to that mobile indicating the position of the
vehicle in terms of latitude and longitude.
3.3 Circuit OperationThe project is vehicle positioning and
navigation system we can locate the vehicle around the globe with
ARM7microcontroller, GPS receiver, GSM modem, Power supply.
Microcontroller used is ARM7. The code is written in the internal
memory of Microcontroller i.e. ROM. With help of instruction set it
processes the instructions and it acts as interface between GSM and
GPS with help of serial communication of ARM7. GPS always transmits
the data and GSM transmits and receive the data. GPS pin TX is
connected to microcontroller via serial ports. GSM pins TX and RX
are connected to microcontroller.3.3.1 PowerThe power is supplied
to components like GSM, GPS and Micro control circuitry using a
12V/3.2A battery .GSM requires 12v,GPS and microcontroller requires
5v .with the help of regulators we regulate the power between three
components.
3.3.2 Serial portsMicrocontroller communicates with the help of
serial communication. First it takes the data from the GPS receiver
and then sends the information to the owner in the form of SMS with
help of GSM modem.
CHAPTER 4MICROCONTROLLER ARM7
Why we use ARM7?The ARM processor is a 32-bit RISC processor,
meaning it is built using the reduced instruction set computer
(RISC) instruction set architecture (ISA). ARM processors are
microprocessors and are widely used in many of the mobile phones
sold each year, as many as 98% of mobile phones. They are also used
in personal digital assistants (PDA), digital media and music
layers, hand-held gaming systems, calculators, and even computer
hard drives.The first ARM processor-based computer was the Acorn
Archimedes, released in 1987. Apple Computer became involved with
helping to improve the ARM technology in the late 1980s, with their
work resulting in the ARM6 technology in 1992. Later, Acorn used
the ARM6-based ARM 610 processor in their Risc PC computers in
1994. Today, the ARM architecture is licensed for use by many
companies, including Apple, Cirrus Logic, Intel, LG, Microsoft,
NEC, Nintendo, Nvidia, Sony, Samsung, Sharp, Texas Instruments,
Yamaha, and many more. The latest developed ARM processor families
include ARM11 and Cortex. ARM processors capable of 64-bit
processing are currently in development.
4.1 FeaturesThe main features of the microcontroller are:
16/32-bit ARM7 microcontroller. 8 to 40kB of on-chip static RAM
and 32 to 512kB of on-chip flash program memory. 128 bit wide
interface/accelerator enables high speed 60 MHz operation.
In-System/In-Application Programming (ISP/IAP) via on-chip
boot-loader software. Single flash sector or full chip erase in 400
ms and programming of 256bytes in 1ms. Embedded ICE RT and Embedded
Trace interfaces offer real-time debugging with the on-chip Real
Monitor software and high speed tracing of instruction execution.
USB 2.0 Full Speed compliant Device Controller with 2kB of endpoint
RAM. In addition, the LPC2148 provides 8kB of on-chip RAM
accessible to USB by DMA. One or two (LPC2141/2 vs. LPC2148) 10-bit
A/D converters provide a total of 6/14 analog inputs, with
conversion times as low as 2.44 s per channel. Single 10-bit D/A
converter provide variable analog output. Two 32-bit
timers/external event counters (with four capture and four compare
channels each), PWM unit (six outputs) and watchdog. Low power
real-time clock with independent power and dedicated 32 kHz clock
input. Multiple serial interfaces including two UARTs (16C550), two
Fast I2C-bus (400kbit/s), SPI and SSP with buffering and variable
data length capabilities. Vectored interrupt controller with
configurable priorities and vector addresses. Up to nine edge or
level sensitive external interrupt pins available. On-chip
integrated oscillator operates with an external crystal in range
from 1 MHz to 30 MHz and with an external oscillator up to 50MHz.
Individual enable/disable of peripheral functions as well as
peripheral clock scaling for additional power optimization.
Processor wake-up from Power-down mode via external interrupt, USB,
Brown-Out Detect (BOD) or Real-Time Clock (RTC). Single power
supply chip with Power-On Reset (POR) and BOD circuits: CPU
operating voltage range of 3.0 V to 3.6 V (3.3 V 10 %) with 5 V
tolerant I/O pads.
4.2The Pin Configuration 4.2.1 Special Function Registers
(SFR)
4.3 Memory OrganizationOn-chip flash memory system: The
LPC2141/2/4/6/8 incorporate a 32kB, 64kB, 128kB, 256kB, and 512kB
Flash memory system, respectively. This memory may be used for both
code and data storage. Programming of the Flash memory may be
accomplished in several ways: over the serial built-in JTAG
interface, using In System Programming (ISP) and UART0, or by means
of In Application Programming (IAP) capabilities. The application
program, using the IAP functions, may also erase and/or program the
Flash while the application is running, allowing a great degree of
flexibility for data storage field firmware upgrades, etc. When the
LPC2141/2/4/6/8 on-chip bootloader is used, 32kB, 64kB, 128kB,
256kB, and 500kB of Flash memory is available for user code. The
LPC2141/2/4/6/8 Flash memory provides minimum of 100,000
erase/write cycles and 20 years of data-retention.On-chip Static
RAM (SRAM): On-chip Static RAM (SRAM) may be used for code and/or
data storage. The on-chip SRAM may be accessed as 8-bits, 16-bits,
and 32-bits. The LPC2141/2/4/6/8 provides 8/16/32kB of static RAM,
respectively.
4.4 SYSTEM CONTROL BLOCKThe System Control Block includes
several system features and control registers for a number of
functions that are not related to specific peripheral devices.
These include: Crystal Oscillator External Interrupt Inputs
Miscellaneous System Controls and Status Memory Mapping Control PLL
Power Control Reset APB Divider Wakeup Timer Each type of function
has its own register(s) if any are required and unneeded bits are
defined as reserved in order to allow future expansion. Unrelated
functions never share the same register addresses
CHAPTER 5GSM MODULE5.1 GSM HistoryThe acronym for GSM is Global
System for Mobile Communications. During the early 1980s, analog
cellular telephone systems were experiencing rapid growth in
Europe, particularly in Scandinavia and the United Kingdom, but
also in France and Germany. Each country developed its own system,
which was incompatible with everyone else's in equipment and
operation. This was an undesirable situation, because not only was
the mobile equipment limited to operation within national
boundaries, which in a unified Europe were increasingly
unimportant, but there was also a very limited market for each type
of equipment, so economies of scale and the subsequent savings
could not be realized.The Europeans realized this early on, and in
1982 the Conference of European Posts and Telegraphs (CEPT) formed
a study group called the Groupe Special Mobile (GSM) to study and
develop a pan-European public land mobile system. The proposed
system had to meet certain criteria:1. Good subjective speech
quality 2. Low terminal and service cost 3. Low terminal and
service cost 4. Ability to support handheld terminals 5. Support
for range of new services and facilities 6. Spectral efficiency 7.
ISDN compatibility 8. Pan-European means European-wide. ISDN
throughput at 64Kbs was never envisioned, indeed, the highest rate
a normal GSM network can achieve is 9.6kbs. Europe saw cellular
service introduced in 1981, when the Nordic Mobile Telephone System
or NMT450 began operating in Denmark, Sweden, Finland, and Norway
in the 450 MHz range. It was the first multinational cellular
system. In 1985 Great Britain started using the Total Access
Communications System or TACS at 900MHz. Later, the West German
C-Netz, the French Radio COM 2000, and the Italian RTMI/RTMS helped
make up Europe's nine analog incompatible radio telephone systems.
Plans were afoot during the early 1980s, however, to create a
single European wide digital mobile service with advanced features
and easy roaming. While North American groups concentrated on
building out their robust but increasingly fraud plagued and
featureless analog network, Europe planned for a digital future.In
1989, GSM responsibility was transferred to the European
Telecommunication Standards Institute (ETSI), and phase I of the
GSM specifications were published in 1990. Commercial service was
started in mid-1991, and by 1993 there were 36 GSM networks in 22
countries. Although standardized in Europe, GSM is not only a
European standard. Over 200 GSM networks (including DCS1800 and
PCS1900) are operational in 110 countries around the world. In the
beginning of 1994, there were 1.3 million subscribers worldwide,
which had grown to more than 55 million by October 1997. With North
America making a delayed entry into the GSM field with a derivative
of GSM called PCS1900, GSM systems exist on every continent, and
the acronym GSM now aptly stands for Global System for Mobile
communications.The developers of GSM chose an unproven (at the
time) digital system, as opposed to the then-standard analog
cellular systems like AMPS in the United States and TACS in the
United Kingdom. They had faith that advancements in compression
algorithms and digital signal processors would allow the fulfilment
of the original criteria and the continual improvement of the
system in terms of quality and cost. The over 8000 pages of GSM
recommendations try to allow flexibility and competitive innovation
among suppliers, but provide enough standardization to guarantee
proper networking between the components of the system. This is
done by providing functional and interface descriptions for each of
the functional entities defined in the system.
5.2 Services Provided by GSMFrom the beginning, the planners of
GSM wanted ISDN compatibility in terms of the services offered and
the control signalling used. However, radio transmission
limitations, in terms of bandwidth and cost, do not allow the
standard ISDN B-channel bit rate of 64 kbps to be practically
achieved.Telecommunication services can be divided into bearer
services, teleservices, and supplementary services. The most basic
teleservice supported by GSM is telephony. As with all other
communications, speech is digitally encoded and transmitted through
the GSM network as a digital stream. There is also an emergency
service, where the nearest emergency-service provider is notified
by dealing three digits.a) Bearer services: Typically data
transmission instead of voice. Fax and SMS are examples. b)
Teleservices: Voice oriented traffic. c) Supplementary services:
Call forwarding, caller ID, call waiting and the like.
A variety of data services is offered. GSM users can send and
receive data, at rates up to 9600 bps, to users on POTS (Plain Old
Telephone Service), ISDN, Packet Switched Public Data Networks, and
Circuit Switched Public Data Networks using a variety of access
methods and protocols, such as X.25 or X.32. Since GSM is a digital
network, a modem is not required between the user and GSM network,
although an audio modem is required inside the GSM network to
interwork with POTS.Other data services include Group 3 facsimile,
as described in ITU-T recommendation T.30, which is supported by
use of an appropriate fax adaptor. A unique feature of GSM, not
found in older analog systems, is the Short Message Service (SMS).
SMS is a bidirectional service for short alphanumeric (up to 160
bytes) messages. Messages are transported in a store-and-forward
fashion. For point-to-point SMS, a message can be sent to another
subscriber to the service, and an acknowledgement of receipt is
provided to the sender. SMS can also be used in a cell-broadcast
mode, for sending messages such as traffic updates or news updates.
Messages can also be stored in the SIM card for later
retrieval.Supplementary services are provided on top of
teleservices or bearer services. In the current (Phase I)
specifications, they include several forms of call forward (such as
call forwarding when the mobile subscriber is unreachable by the
network), and call barring of outgoing or incoming calls, for
example when roaming in another country. Many additional
supplementary services will be provided in the Phase 2
specifications, such as caller identification, call waiting,
multi-party conversations.
5.3 Mobile StationThe mobile station (MS) consists of the mobile
equipment (the terminal) and a smart card called the Subscriber
Identity Module (SIM). The SIM provides personal mobility, so that
the user can have access to subscribed services irrespective of a
specific terminal. By inserting the SIM card into another GSM
terminal, the user is able to receive calls at that terminal, make
calls from that terminal, and receive other subscribed services.The
mobile equipment is uniquely identified by the International Mobile
Equipment Identity (IMEI). The SIM card contains the International
Mobile Subscriber Identity (IMSI) used to identify the subscriber
to the system, a secret key for authentication, and other
information. The IMEI and the IMSI are independent, thereby
allowing personal mobility. The SIM card may be protected against
unauthorized use by a password or personal identity number.GSM
phones use SIM cards, or Subscriber information or identity
modules. They're the biggest difference a user sees between a GSM
phone or handset and a conventional cellular telephone. With the
SIM card and its memory the GSM handset is a smart phone, doing
many things a conventional cellular telephone cannot. Like keeping
a built in phone book or allowing different ring tones to be
downloaded and then stored. Conventional cellular telephones either
lack the features GSM phones have built in, or they must rely on
resources from the cellular system itself to provide them. Let me
make another, important point.With a SIM card your account can be
shared from mobile to mobile, at least in theory. Want to try out
your neighbours brand new mobile? You should be able to put your
SIM card into that GSM handset and have it work. The GSM network
cares only that a valid account exists, not that you are using a
different device. You get billed, not the neighbour who loaned you
the phone.This flexibility is completely different than AMPS
technology, which enables one device per account. No switching
around. Conventional cellular telephones have their electronic
serial number burned into a chipset which is permanently attached
to the phone. No way to change out that chipset or trade with
another phone. SIM card technology, by comparison, is meant to make
sharing phones and other GSM devices quick and easy.
5.4 Base Station Subsystem:The Base Station Subsystem is
composed of two parts, the Base Transceiver Station (BTS) and the
Base Station Controller (BSC). These communicate across the
standardized Abis interface, allowing (as in the rest of the
system) operation between components made by different
suppliers.The Base Transceiver Station houses the radio
transceivers that define a cell and handles the radio-link
protocols with the Mobile Station. In a large urban area, there
will potentially be a large number of BTSs deployed, thus the
requirements for a BTS are ruggedness, reliability, portability,
and minimum cost.The BTS or Base Transceiver Station is also called
an RBS or Remote Base station. Whatever the name, this is the radio
gear that passes all calls coming in and going out of a cell site.
The base station is under direction of a base station controller so
traffic gets sent there first. The base station controller,
described below, gathers the calls from many base stations and
passes them on to a mobile telephone switch. From that switch come
and go the calls from the regular telephone network. Some base
stations are quite small; the one pictured here is a large outdoor
unit. The large number of base stations and their attendant
controllers are a big difference between GSM and IS-136.5.4.1 Base
Station ControllerThe Base Station Controller manages the radio
resources for one or more BTSs. It handles radio-channel setup,
frequency hopping, and handovers, as described below. The BSC is
the connection between the mobile station and the Mobile service
Switching Centre (MSC).Another difference between conventional
cellular and GSM is the base station controller. It's an
intermediate step between the base station transceiver and the
mobile switch. GSM designers thought this a better approach for
high density cellular networks. As one anonymous writer penned, "If
every base station talked directly to the MSC, traffic would become
too congested. To ensure quality communications via traffic
management, the wireless infrastructure network uses Base Station
Controllers as a way to segment the network and control congestion.
The result is that MSCs route their circuits to BSCs which in turn
are responsible for connectivity and routing of calls for 50 to 100
wireless base stations."Many GSM descriptions picture equipment
called a TRAU, which stands for Transcoding Rate and Adaptation
Unit. Of course also known as a Trans-Coding Unit or TCU, the TRAU
is a compressor and converter. It first compresses traffic coming
from the mobiles through the base station controllers. That's quite
an achievement because voice and data have already been compressed
by the voice coders in the handset. Anyway, it crunches that data
down even further. It then puts the traffic into a format theMobile
Switch can understand. This is the Trans-Coding part of its name,
where code in one format is converted to another. The TRAU is not
required but apparently it saves quite a bit of money to install
one.Here's how Nortel Networks sells their unit: Reduce
transmission resources and realize up to 75% transmission cost
savings with the TCU.""The Trans-Coding Unit (TCU), inserted
between the BSC and MSC, enables speech compression and data rate
adaptation within the radio cellular network. The TCU is designed
to reduce transmission costs by minimizing transmission resources
between the BSC and MSC. This is achieved by reducing the number of
PCM links going to the BSC, since four traffic channels (data or
speech) can be handled by one PCM time slot. Additionally, the
modular architecture of the TCU supports all three GSM vocoders
(Full Rate, Enhanced Full Rate, and Half Rate) in the same cabinet,
providing you with a complete range of deployment options."Voice
coders or vocoders are built into the handsets a cellular carrier
distributes. They're the circuitry that turns speech into digital.
The carrier specifies which rate they want traffic compressed,
either a great deal or just a little. The cellular system is
designed this way, with handset vocoders working in league with the
equipment of the base station subsystem.
5.5 Architecture of the GSM NetworkA GSM network is composed of
several functional entities, whose functions and interfaces are
specified. Figure 1 shows the layout of a generic GSM network. The
GSM network can be divided into three broad parts. The Mobile
Station is carried by the subscriber. The Base Station Subsystem
controls the radio link with the Mobile Station. The Network
Subsystem, the main part of which is the Mobile services Switching
Centre (MSC), performs the switching of calls between the mobile
users, and between mobile and fixed network users. The MSC also
handles the mobility management operations. Not shown is the
Operations and Maintenance Centre, which oversees the proper
operation and setup of the network. The Mobile Station and the Base
Station Subsystem communicate across the Um interface, also known
as the air interface or radio link. The Base Station Subsystem
communicates with the Mobile services Switching Centre across the A
interface.As John states, he presents a generic GSM architecture.
Lucent, Ericsson, Nokia, and others feature their own vision in
their own diagrams.Lucent GSM architecture/Ericsson GSM
architecture/Nokia GSM architecture/Siemenss GSM architecture.
5.6 Radio Link AspectsThe International Telecommunication Union
(ITU), which manages the international allocation of radio spectrum
(among many other functions), allocated the bands 890-915 MHz for
the uplink (mobile station to base station) and 935-960 MHz for the
downlink (base station to mobile station) for mobile networks in
Europe. Since this range was already being used in the early 1980s
by the analog systems of the day, the CEPT had the foresight to
reserve the top 10 MHz of each band for the GSM network that was
still being developed. Eventually, GSM will be allocated the entire
2x25 MHz bandwidth.
5.7 Multiple Access and Channel Structure:Since radio spectrum
is a limited resource shared by all users, a method must be devised
to divide up the bandwidth among as many users as possible. The
method chosen by GSM is a combination of Time- and
Frequency-Division Multiple Access (TDMA/FDMA). The FDMA part
involves the division by frequency of the (maximum) 25 MHz
bandwidth into 124 carrier frequencies spaced 200 kHz apart. One or
more carrier frequencies are assigned to each base station. Each of
these carrier frequencies is then divided in time, using a TDMA
scheme. The fundamental unit of time in this TDMA scheme is called
a burst period and it lasts 15/26 ms (or approx. 0.577 ms). Eight
burst periods are grouped into a TDMA frame (120/26 ms, or approx.
4.615 ms), which forms the basic unit for the definition of logical
channels. One physical channel is one burst period per TDMA
frame.i) Traffic channels A traffic channel (TCH) is used to carry
speech and data traffic. Traffic channels are defined using a
26-frame multi-frame, or group of 26 TDMA frames. The length of a
26-frame multi-frame is 120 ms, which is how the length of a burst
per