GPS Tracking System Project Report

GPS TRACKING SYSTEM

(1)INTRODUCTION (1.1) WHAT IS GPS TRACKING SYSTEM? A GPS tracking unit is a device that uses the Global Positioning System to determine the precise location of a vehicle, person, or other asset to which it is attached and to record the position of the asset at regular intervals. The recorded location data can be stored within the tracking unit, or it may be transmitted to a central location data base, or internet-connected computer, using a cellular (GPRS), radio, or satellite modem embedded in the unit. This allows the asset's location to be displayed against a map backdrop either in real-time or when analysing the track later, using customized software. A GPS tracking system uses the GNSS (Global Navigation Satellite System) network. This network incorporates a range of satellites that use microwave signals which are transmitted to GPS devices to give information on location, vehicle speed, time and direction. So, a GPS tracking system can potentially give both real-time and historic navigation data on any kind of journey. A GPS tracking system can work in various ways. From a commercial perspective, GPS devices are generally used to record the position of vehicles as they make their journeys. Some systems will store the data within the GPS tracking system itself (known as passive tracking) and some send the information to a centralized database or system via a modem within the GPS system unit on a regular basis (known as active tracking).  A PASSIVE GPS TRACKING SYSTEM will monitor location and will store its data on journeys based on certain types of events. So, for example, this kind of GPS system may log data such as turning the ignition on EN DEPARTMENT, SRMGPC, LUCKNOW

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or off or opening and closing doors. The data stored on this kind of GPS tracking system is usually stored in internal memory or on a memory card which can then be downloaded to a computer at a later date for analysis. In some cases the data can be sent automatically for wireless download at predetermined points/times or can be requested at specific points during the journey.  AN ACTIVE GPS TRACKING SYSTEM is also known as a real-time system as this method automatically sends the information on the GPS system to a central computer or system in real-time as it happens. This kind of system is usually a better option for commercial purposes such as fleet tracking and individual vehicle tracking as it allows the company to know exactly where their vehicles are, whether they are on time and whether they are where they are supposed to be during a journey. This is also a useful way of monitoring the behavior of employees as they carry out their work and of streamlining internal processes and procedures for delivery fleets.

(1.2) WHAT IS GPS? The Global Positioning System (GPS) is actually a constellation of 27 Earth-orbiting satellites (24 in operation and three extras in case one fails). 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 at about 12,000 miles (19,300 km), 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.

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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.

(Photo courtesy U.S. Department of Defense Artist's concept of the GPS satellite constellation)

Figure (1.2.1) In order to make the simple calculation of the location, then, the GPS receiver has to know two things:  The location of at least three satellites above you  The distance between you and each of those satellites

(Photo courtesy Garmin The Street Pilot II, a GPS receiver with built-in maps for drivers)

Figure (1.2.2)

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The GPS receiver figures both of these things out by analyzing high-frequency, lowpower radio signals from the GPS satellites. Better units have multiple receivers, so they can pick up signals from several satellites simultaneously. You can use maps stored in the receiver's memory, connect the receiver to a computer that can hold more detailed maps in its memory, or simply buy a detailed map of your area and find your way using the receiver's latitude and longitude readouts. Some receivers let you download detailed maps into memory or supply detailed maps with plug-in map cartridges. A standard GPS receiver will not only place you on a map at any particular location, but will also trace your path across a map as you move. If you leave your receiver on, it can stay in constant communication with GPS satellites to see how your location is changing. With this information and its built-in clock, the receiver can give you several pieces of valuable information:  How far you've traveled (odometer)  How long you've been traveling  Your current speed (speedometer)  Your average speed  A "bread crumb" trail showing you exactly where you have traveled on the map  The estimated time of arrival at your destination if you maintain your current speed

(1.3) TYPES OF GPS TRACKING SYSTEM: Three Types of GPS Tracking Units are there. There are currently three categories of GPS tracking units. The categories are split into how GPS data is logged and retrieved.

Data Loggers EN DEPARTMENT, SRMGPC, LUCKNOW

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Data loggers are usually the most basic type of GPS tracking; a GPS data logger simply logs the position of the object at regular intervals and retains it in an internal memory. Usually, GPS loggers have flash memory on board to record data that is logged. The flash memory can then be transferred and accessed using USB or accessed on the device itself. Usually data loggers are devices used for sports and hobby activities. They might include devices that help log location for hikers, bikers and joggers.

Data Pushers Data Pushers are GPS tracking units that are mainly used for security purposes. A data pusher GPS tracking unit sends data from the device to a central database at regular intervals, updating location, direction, speed and distance. Data pushers are common in fleet control to manage trucks and other vehicles. For instance, delivery vehicles can be located instantly and their progress can be tracked. Other uses include the ability to track valuable assets. If valuable goods are being transported or even if they reside in a specific location, they can constantly be monitored to avoid theft. Data pushers are also common for espionage type tasks. It is extremely easy to watch the movements of an individual or valuable asset. This particular use of GPS tracking has become an important issue in the field of GPS tracking, because of its potential for abuse.

Data Pullers The last category of GPS tracking units is the data pusher units. These types of units push data or send data when the unit reach a specific location or at specific intervals. These GPS units are usually always on and constantly monitoring their location. Most, if not all data puller unit also allow data pushing (the ability to query a location and other data from a GPS tracking unit).

(1.4) FEATURES OF THE GPS TRACKING SYSTEM: EN DEPARTMENT, SRMGPC, LUCKNOW

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Generally all of the GPS Tracking System has some of the common features that are listed below: GSM/Gprs Module - It is used to send the location to the user online. In some case, if the user wants the location through the internet then this module is very useful. By the help of the GSM/GPRS module, we can send data real time. It can be seen on the internet enabled any device as a PC, mobile phone, PDA etc.  Track Playback - Animates your driver's daily driven route so that you can follow every move. The track animation line is color coded to indicate the speed your driver was traveling during his route.  Idle Time Report- Gives you an accurate report detailing when your driver was stopped and has left the engine running on the vehicle. This report was designed with input from our existing customers who were concerned about high fuel bills.  Track Detail - Provides you with a split screen view when reviewing your driver's route. Stop and transit times, as well as speed information, are displayed in the bottom pane. You can easily toggle between stops by clicking the stop number on the track detail pane.

(1.5) GPS POSITION LOCATION PRINCIPLE: The Global Positioning System is comprised of three segments: Satellite constellation ground control/ monitoring network and user receiving equipment. Formal GPS joint program office (JPO) programmatic terms for these components are space, operational control and user equipment segments, respectively. –

The satellite constellation contains the satellites in orbit that provide the ranging signals and data messages to the user equipment.

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Figure 1.5.1 –

The operational control segment (OCS) tracks and maintains the satellites in space. The OCS monitors satellite health and signal integrity and maintains the orbital configuration of the satellite. Furthermore, the OCS updates the satellite clock corrections and ephemerides as well as numerous other parameters essential to determining user position, velocity and time (PVT).

–

The user receiver equipment performs the navigation, timing or other related notation.

(1.6) GPS SIGNALS: –

The satellites of the Global Positioning System (GPS) broadcast radio signals to enable GPS receivers on or near the Earth's surface to determine location and synchronized time. The GPS system itself is operated by the U.S. Department of Defense for both military use and use by the general public.

–

GPS signals include ranging signals, used to measure the distance to the satellite, and navigation messages. The navigation messages include ephemeris data, used to calculate the position of each satellite in orbit, and

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information about the time and status of the entire satellite constellation, called the almanac.

Basic GPS signals: The original GPS design contains two ranging codes: the Coarse/Acquisition (C/A) code, which is freely available to the public, and the restricted Precision (P) code, usually reserved for military applications.

Coarse/Acquisition code: The C/A code is a 1,023 bit deterministic sequence called pseudorandom noise (also pseudorandom binary sequence) (PN or PRN code) which, when transmitted at 1.023 megabits per second (Mbit/s), repeats every millisecond. These sequences only match up, or strongly correlate, when they are exactly aligned. Each satellite transmits a unique PRN code, which does not correlate well with any other satellite's PRN code. In other words, the PRN codes are highly orthogonal to one another. This is a form of code division multiple access (CDMA), which allows the receiver to recognize multiple satellites on the same frequency.

Precision code: –

The P-code is also a PRN; however, each satellite's P-code PRN code is 6.1871 × 1012 bits long (6,187,100,000,000 bits, ~720.213 gigabytes) and only repeats once a week (it is transmitted at 10.23 Mbit/s). The extreme length of the Pcode increases its correlation gain and eliminates any range ambiguity within the Solar System. However, the code is so long and complex it was believed that a receiver could not directly acquire and synchronize with this signal alone. It was expected that the receiver would first lock onto the relatively

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simple C/A code and then, after obtaining the current time and approximate position, synchronize with the P-code. –

Whereas the C/A PRNs are unique for each satellite, the P-code PRN is actually a small segment of a master P-code approximately 2.35 × 1014 bits in length (235,000,000,000,000 bits, ~26.716 terabytes) and each satellite repeatedly transmits its assigned segment of the master code.

–

To prevent unauthorized users from using or potentially interfering with the military signal through a process called spoofing, it was decided to encrypt the P-code. To that end the P-code was modulated with the W-code, a special encryption sequence, to generate the Y-code. The Y-code is what the satellites have been transmitting since the anti-spoofing module was set to the "on" state. The encrypted signal is referred to as the P(Y)-code.

–

The details of the W-code are kept secret, but it is known that it is applied to the P-code at approximately 500 kHz, which is a slower rate than that of the Pcode itself by a factor of approximately 20. This has allowed companies to develop semi-codeless approaches for tracking the P(Y) signal, without knowledge of the W-code itself.

(1.7)FREQUENCIES USED BY GPS SIGNALS: –

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 spreadspectrum technique where the low-bitrate message data is encoded with a highrate 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 P codes,

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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. Table 1.7.1: GPS Frequency Overview

Each composite signal (in-phase and quadrature phase) becomes:

where data

and

represent signal powers;

and

represent codes with/without

.

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(1.8) GPS CALCULATIONS: At a particular time (let's say midnight), the satellite begins transmitting a long, digital pattern called a pseudo-random code. The receiver begins running the same digital pattern also exactly at midnight. When the satellite's signal reaches the receiver, its transmission of the pattern will lag a bit behind the receiver's playing of the pattern.The length of the delay is equal to the signal's travel time. The receiver multiplies this time by the speed of light to determine how far the signal traveled. Assuming the signal traveled in a straight line, this is the distance from receiver to satellite.

Figure 1.8.1: (A GPS satellite,Photo courtesy U.S. Army) In order to make this measurement, the receiver and satellite both need clocks that can be synchronized down to the nanosecond. To make a satellite positioning system using only synchronized clocks, you would need to have atomic clocks not only on all the satellites, but also in the receiver itself. But atomic clocks cost somewhere between $50,000 and $100,000, which makes them a just a bit too expensive for everyday consumer use.

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The Global Positioning System has a clever, effective solution to this problem. Every satellite contains an expensive atomic clock, but the receiver itself uses an ordinary quartz clock, which it constantly resets. In a nutshell, the receiver looks at incoming signals from four or more satellites and gauges its own inaccuracy. In other words, there is only one value for the "current time" that the receiver can use. The correct time value will cause all of the signals that the receiver is receiving to align at a single point in space. That time value is the time value held by the atomic clocks in all of the satellites. So the receiver sets its clock to that time value, and it then has the same time value that all the atomic clocks in all of the satellites have. The GPS receiver gets atomic clock accuracy "for free." When you measure the distance to four located satellites, you can draw four spheres that all intersect at one point. Three spheres will intersect even if your numbers are way off, but four spheres will not intersect at one point if you've measured incorrectly. Since the receiver makes all its distance measurements using its own built-in clock, the distances will all be proportionally incorrect. The receiver can easily calculate the necessary adjustment that will cause the four spheres to intersect at one point. Based on this, it resets its clock to be in sync with the satellite's atomic clock. The receiver does this constantly whenever it's on, which means it is nearly as accurate as the expensive atomic clocks in the satellites. In order for the distance information to be of any use, the receiver also has to know where the satellites actually are. This isn't particularly difficult because the satellites travel in very high and predictable orbits. The GPS receiver simply stores an almanac that tells it where every satellite should be at any given time. Things like the pull of the moon and the sun do change the satellites' orbits very slightly, but the Department of Defense constantly monitors their exact positions and transmits any adjustments to all GPS receivers as part of the satellites' signals. EN DEPARTMENT, SRMGPC, LUCKNOW

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(1.9)GPS ACCURACY: –

The accuracy of a position determined with GPS depends on the type of receiver. Most hand-held GPS units have about 10-20 meter accuracy.

–

Other types of receivers use a method called Differential GPS (DGPS) to obtain much higher accuracy.

–

DGPS requires an additional receiver fixed at a known location nearby.

–

Observations made by the stationary receiver are used to correct positions recorded by the roving units, producing an accuracy greater than 1 meter.

–

When the system was created, timing errors were inserted into GPS transmissions to limit the accuracy of non-military GPS receivers to about 100 meters.

–

This part of GPS operations, called Selective Availability, was eliminated in May 2000.

(1.10) OBJECTIVE: To locate the position of the any object or person attached with GPS receiver.

(2) LITERATURE REVIEW (2.1) THEORY: The GPS system belongs to the Department of Defense (DOD) and is officially known as the NAVSTAR System (Navigation Satellite Timing and Ranging). Its primary mission is to provide the U.S. Government and the Department of Defense the ability

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to accurately determine one’s position at any point on the earth’s surface, at any time of the day or night, and in any weather condition. Sounds simple, but it took a number of years and a commitment of over 12 billion dollars before the first GPS satellite was deployed. As originally envisioned, a minimum constellation of 24 satellites would be required to meet the objectives of the GPS program. More than 24 would provide redundancy and additional accuracy. Satellites would have a design life of 10 to 13 years, and would be replaced as needed. The full complement of 24 operational satellites was finally realized in 1994, more than 20 years after the system was originally proposed. (Constellation of 24 GPS satellites) Figure 2.1.1 Although GPS was originally envisioned for military use, it soon became obvious that there would be numerous civilian applications as well. The first two major civilian applications were marine navigation and surveying. Since then, a myriad of applications have emerged, from personal positioning for scientific, commercial, and recreational uses, to truck fleet management, map-based navigation aids for automobiles and hand held computers, landing aids for aircraft, control of construction and agricultural machinery and, in the near future, reporting of exact cell-phone locations for emergency response purposes. As with many technologies, the uses of GPS extend far beyond what the original designers envisioned. As receivers have shrunk in size and weight and costs continue to drop, the number of users and applications has grown rapidly.

(2.2) Components of the GPS System: There are 3 main components to the GPS system. These components are known as Segments, as follows:  Space Segment - the satellites, also known as space vehicles or SVs  Control Segment - ground stations run by the DOD  User Segment - all users and their GPS receivers EN DEPARTMENT, SRMGPC, LUCKNOW

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These three segments are illustrated schematically below.

Figure 2.2.1 • Space Segment: Twenty four separate individual satellites situated in their own orbit above 11,000 nautical miles from the earth consists space segment. • Control Segment: Control segment component is the control station which works to check out the functions of satellite, whether these are properly working or not. There are only five control stations situated in the entire world. • User Segment: This component is made for the user. User can hold it in its hand or it can be mounted in the car. It works as a receiver.

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Figure 2.2.2

(3) PROPOSED METHODOLOGY (3.1) COMPLETE BLOCK DIAGRAM:  ON BOARD BLOCK DIAGRAM:

GPS Tx

ATMEGA 8 MICROCONTROLLER

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GPS MODULE

LCD

Figure 3.1.1 

OFF BOARD BLOCK DIAGRAM:

GPS Rx

ATMEGA 8 MICROCONTROLLER

POWER SUPPLY

LCD

Figure 3.1.2

(3.2) DESCRIPTION: GPS Tracking System works on the principle of satellite communication. In On board block diagram, there is GPS module. Intially, it takes the signal from the satellite then it sends the command to ATMEGA 8 microcontroller. Then this microcontroller, sends a signal to GPS transmitter that signal will also be displayed on LCD screen, connected in on board diagram.

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Transmitted signal by GPS transmitter will be received by GPS receiver connected in Off board block diagram. Then ATMEGA 8 microcontroller, sends the signal to LCD, which will display the position of the receiver. Two LCD’s are used in our project for matching purpose, accuracy if the position of receiver is changed, then the new position can also be find.

S.NO (1)

SPECIFICATIONS

RATINGS

QUANTITY

(4) SOFTWARE/HARDWARE 5V

GPS MODULE

1

AT MEGA 8 5V 2 REQUIREMENTS AND SPECIFICATIONS MICROCONTROLLER

(2) (3)

Table 4.1: Components Used CAPACITORS 10 µF

6

(4)

RESISTANCES

18

(5)

LCD {16X2}

GPS TRANSMITTER EN(6) DEPARTMENT, SRMGPC, LUCKNOW (7)

GPS RECEIVER

(8)

IC 7805

(9)

LED

4.7 KΩ

2 433 MHz

1

433 MHz

1

5-18 V

2 3

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(4.1) DESCRIPTIONS OF EACH COMPONENT: I. ATMEGA 8 MICROCONTROLLER :

a) FEATURES: •

High-performance, Low-power Atmel®AVR® 8-bit Microcontroller

•

Advanced RISC Architecture

 130 Powerful Instructions – Most Single-clock Cycle Execution  32 × 8 General Purpose Working Fully Static Operation  Up to 16 MIPS Throughput at 16MHz  On-chip 2-cycle Multiplier EN DEPARTMENT, SRMGPC, LUCKNOW

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•

High Endurance Non-volatile Memory segments

 8Kbytes of In-System Self-programmable Flash program memory  512Bytes EEPROM  1Kbyte Internal SRAM  Write/Erase Cycles: 10,000 Flash/100,000 EEPROM  Data retention: 20 years at 85°C/100 years at 25°C  Optional Boot Code Section with Independent Lock Bits In-System Programming by On-chip Boot Program True Read-While-Write Operation  Programming Lock for Software Security •

Peripheral Features

 Two 8-bit Timer/Counters with Separate Prescaler, one Compare Mode  One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture mode  Real Time Counter with Separate Oscillator  Three PWM Channels  8-channel ADC in TQFP and QFN/MLF package Eight Channels 10-bit Accuracy  6-channel ADC in PDIP package Six Channels 10-bit Accuracy EN DEPARTMENT, SRMGPC, LUCKNOW

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 Byte-oriented Two-wire Serial Interface  Programmable Serial USART  Master/Slave SPI Serial Interface  Programmable Watchdog Timer with Separate On-chip Oscillator  On-chip Analog Comparator •

Special Microcontroller Features

 Power-on Reset and Programmable Brown-out Detection  Internal Calibrated RC Oscillator  External and Internal Interrupt Sources  Five Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, and  Standby •

I/O and Packages

 23 Programmable I/O Lines  28-lead PDIP, 32-lead TQFP, and 32-pad QFN/MLF •

Operating Voltages

 4.5V - 5.5V (ATmega8) •

Speed Grades

 0 - 16MHz (ATmega8) •

Power Consumption at 4Mhz, 3V, 25°C

 Active: 3.6mA  Idle Mode: 1.0mA  Power-down Mode: 0.5Μa

b) PIN DESCRIPTIONS:

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

VCC: Digital supply voltage.



GND: Ground.



Port B (PB7-PB0) XTAL1/XTAL2/TOSC1/TOSC2:

–

Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port B output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port B pins that are externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset condition becomes active, even if the clock is not running.

–

Depending on the clock selection fuse settings, PB6 can be used as input to the inverting Oscillator amplifier and input to the internal clock operating circuit.

–

Depending on the clock selection fuse settings, PB7 can be used as output from the inverting Oscillator amplifier.

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–

If the Internal Calibrated RC Oscillator is used as chip clock source, PB7..6 is used as TOSC2.1 input for the Asynchronous Timer/Counter2 if the AS2 bit in ASSR is set.



Port C (PC5-PC0):

–

Port C is a 7-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port C output buffers have symmetrical drive characteristics with both high sink and source capability.

–

As inputs, Port C pins that are externally pulled low will source current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset condition becomes active, even if the clock is not running.



PC6/RESET:

–

If the RSTDISBL Fuse is programmed, PC6 is used as an I/O pin. Note that the electrical characteristics of PC6 differ from those of the other pins of Port C.

–

If the RSTDISBL Fuse is unprogrammed, PC6 is used as a Reset input. A low level on this pin for longer than the minimum pulse length will generate a Reset, even if the clock is not running.



Port D (PD7-PD0):

–

Port D is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port D output buffers have symmetrical drive characteristics with both high sink and source capability.

–

As inputs, Port D pins that are externally pulled low will source current if the pull-up resistors are activated. The Port D pins are tri-stated when a reset condition becomes active, even if the clock is not running.



RESET:

–

Reset input. A low level on this pin for longer than the minimum pulse length will generate a reset, even if the clock is not running.

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II.

CAPACITOR: –

A capacitor (originally known as condenser) is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric (insulator)

–

For example, one common construction consists of metal foils separated by a thin layer of insulating film. Capacitors are widely used as parts of electrical circuits in many common electrical devices.

III. RESISTANCE: – The electrical resistance of an electrical element is the opposition to the passage of an electric current through that element; the inverse quantity is electrical conductance, the ease at which an electric current passes. – Electrical resistance shares some conceptual parallels with the mechanical notion of friction. – The SI unit of electrical resistance is the ohm (Ω), while electrical conductance is measured in siemens (S).

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–

An object of uniform cross section has a resistance proportional to its resistivity and length and inversely proportional to its cross-sectional area. All materials show some resistance, except for superconductors, which have a resistance of zero.

IV. LCD (LIQUID CRYSTAL DISPLAY): –

LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of applications. A 16x2 LCD display is very basic module and is very commonly used in various devices and circuits. These modules are preferred over seven segments and other multi segment LEDs.

–

A 16x2 LCD means it can display 16 characters per line and there are 2 such lines. In this LCD each character is displayed in 5x7 pixel matrix. This LCD has two registers, namely, Command and Data.

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–

The command register stores the command instructions given to the LCD. A command is an instruction given to LCD to do a predefined task like initializing it, clearing its screen, setting the cursor position, controlling display etc. The data register stores the data to be displayed on the LCD. The data is the ASCII value of the character to be displayed on the LCD.

a)

PIN DESCRIPTION:

Pin No

Function

Name

1 2 3 4

Ground (0V) Supply voltage; 5V (4.7V – 5.3V) Contrast adjustment; through a variable resistor Selects command register when low; and data register when high

Ground Vcc VEE Register Select

5 6 7 8 9 10 11 12 13 14 15 16

Low to write to the register; High to read from the register Sends data to data pins when a high to low pulse is given

Read/write Enable DB0 DB1 DB2 DB3 DB4 DB5 DB6 DB7 Led+ Led-

b)

8-bit data pins

Backlight VCC (5V) Backlight Ground (0V)

PIN DIAGRAM:

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V. VOLTAGE REGULATOR(IC 7805): –

7805 is a voltage regulator integrated circuit. It is a member of 78xx series of fixed linear voltage regulator ICs. The voltage source in a circuit may have fluctuations and would not give the fixed voltage output. The voltage regulator IC maintains the output voltage at a constant value.

–

The xx in 78xx indicates the fixed output voltage it is designed to provide. 7805 provides +5V regulated power supply. Capacitors of suitable values can be connected at input and output pins depending upon the respective voltage levels.

a) PIN DIAGRAM:

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Pin No.

Function

Name

1 2 3

Input voltage (5V-18V) Ground (0V) Regulated output; 5V (4.8V-5.2V)

Input Ground Output

VI. LIGHT EMITTING DIODE: –

A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting. Introduced as a practical electronic component in 1962, early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet and infrared wavelengths, with very high brightness.

–

When a light-emitting diode is forward biased (switched on), electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence and the color of the

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light (corresponding to the energy of the photon) is determined by the energy gap of the semiconductor. –

LEDs are often small in area (less than 1 mm2), and integrated optical components may be used to shape its radiation pattern.

–

LEDs present many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved robustness, smaller size, faster switching, and greater durability and reliability.

–

LEDs powerful enough for room lighting are relatively expensive and require more precise current and heat management than compact fluorescent lamp sources of comparable output.

VII. GPS RECEIVER: In any satellite receiver since the input power is of the order of picowatts and the C/N to be maintained to get demodulated S/N above the threshold fixed for free processing.

LOWSRMGPC, NOISE LUCKNOW EN DEPARTMENT, BLOCK CONVERTE R

DIGITAL BASEBAN D PROCESSO R

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CPU

GPS TRACKING SYSTEM

I/O

LOCAL OSCILLATOR

EXTERNAL MEMORY

Figure 4.2: (GPS Receiver block diagram) –

This block diagram shows the configuration of GPS receiver. To recover the baseband cost’s loop is used with phase synchronization of local oscillator or else the signal cannot be detected.

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The required PN code is locally generated to detect the chip of the spread spectrum received signal. This requires as many correlators as the visible satellites. Most of the receivers have 12 correlators. Diversity reception is used and the strongest signals are used for processing. The CPU uses software to calculate XY and Z coordinates and hence find latitude, longitude and altitude.

(5) IMPLEMENTATION (5.1) COMPLETE CIRCUIT DIAGRAM :  ON BOARD CIRCUIT DIAGRAM: EN DEPARTMENT, SRMGPC, LUCKNOW

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GPS TRACKING SYSTEM

Figure 5.1.1

 OFF BOARD CIRCUIT DIAGRAM:

EN DEPARTMENT, SRMGPC, LUCKNOW

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GPS TRACKING SYSTEM

Figure 5.1.2

(5.2)WORKING: –

Since ATMEGA 8 microcontroller needs 5V regulated supply hence we use a IC 7805 voltage regulator which converts 12V unregulated supply into 5V regulated supply. LED‘s are used for indicate on purposes.

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Intially, in On board diagram antenna connected to the GPS module receiver takes signal from the satellite’s and then GPS module sends a command signal to the microcontroller.

EN DEPARTMENT, SRMGPC, LUCKNOW

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GPS TRACKING SYSTEM

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The GPS transmitter connected to the microcontroller senses these signal and then transmits a signal which is received by the antenna of GPS receiver connected in the Off board diagram then the GPS receiver sends a signal to microcontroller sends these signal to the LCD for display purpose and then we can see the exact location/position of receiver/object on the LCD in the terms of altitude, latitude, longitude and time.

(5.3)PCB LAYOUT OF CIRCUIT DIAGRAM:  GPS TRANSMITTER:

Figure 5.3.1  GPS RECEIVER:

EN DEPARTMENT, SRMGPC, LUCKNOW

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GPS TRACKING SYSTEM

Figure 5.3.2

(5.4) PICTURE OF HARDWARE LAYOUT: 

ON BOARD:

EN DEPARTMENT, SRMGPC, LUCKNOW

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GPS TRACKING SYSTEM

Figure 5.4.1 

OFF BOARD:

Figure 5.4.2

(5.5) Program to get latitude and longitude value from GPS modem and display it on LCD: EN DEPARTMENT, SRMGPC, LUCKNOW

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/* LCD DATA port----PORT A signal port------PORT B rs-------PB0 rw-------PB1 en-------PB2 */ #define F_CPU 12000000UL #include #include #define USART_BAUDRATE 4800 #define BAUD_PRESCALE (((F_CPU / (USART_BAUDRATE * 16UL))) - 1) #define LCD_DATA PORTA #define ctrl PORTB #define en PB2 #define rw PB1 #define rs PB0 void LCD_cmd(unsigned char cmd); void init_LCD(void); void LCD_write(unsigned char data); void LCD_write_string(unsigned char *str); void usart_init(); unsigned int usart_getch(); unsigned char value,i,lati_value[15],lati_dir, longi_value[15], longi_dir, alti[5] ; int main(void) { DDRA=0xff; DDRB=0x07; init_LCD() EN DEPARTMENT, SRMGPC, LUCKNOW

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GPS TRACKING SYSTEM

_delay_ms(50); LCD_write_string("we at"); LCD_cmd(0xC0); usart_init(); while(1) { value=usart_getch(); if(value=='$') { value=usart_getch(); if(value=='G') { value=usart_getch(); if(value=='P') { value=usart_getch(); if(value=='G') { value=usart_getch(); if(value=='G') { value=usart_getch(); if(value=='A') { value=usart_getch(); if(value==',') { value=usart_getch(); while(value!=',') EN DEPARTMENT, SRMGPC, LUCKNOW

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GPS TRACKING SYSTEM

{ value=usart_getch(); } lati_value[0]=usart_getch(); value=lati_value[0]; for(i=1;value!=',';i++) { lati_value[i]=usart_getch(); value=lati_value[i]; } lati_dir=usart_getch(); value=usart_getch(); while(value!=',') { value=usart_getch(); } longi_value[0]=usart_getch(); value=longi_value[0]; for(i=1;value!=',';i++) { longi_value[i]=usart_getch(); value=longi_value[i]; } longi_dir=usart_getch(); LCD_cmd(0x01); _delay_ms(1); LCD_cmd(0x80); _delay_ms(1000); i=0; EN DEPARTMENT, SRMGPC, LUCKNOW

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GPS TRACKING SYSTEM

while(lati_value[i]!='\0') { LCD_write(lati_value[j]); j++; } LCD_write(lati_dir); LCD_cmd(0xC0); _delay_ms(1000); i=0; while(longi_value[i]!='\0') { LCD_write(longi_value[i]); i++; } LCD_write(longi_dir); _delay_ms(1000) } } } } } } } } } void init_LCD(void) { LCD_cmd(0x38); _delay_ms(1); EN DEPARTMENT, SRMGPC, LUCKNOW

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LCD_cmd(0x01) _delay_ms(1); LCD_cmd(0x0E); _delay_ms(1) LCD_cmd(0x80); _delay_ms(1); return; } void LCD_cmd(unsigned char cmd) { LCD_DATA=cmd; ctrl =(0