live human detection . .

7/28/2019 live human detection . .

1/50

BSTARCT

GSM/GPS Based Live Human Detector

Abstract

Human detection is an essential in some hazardous sectors like boilers, reactors

where only authorized person can enter. The entrance of unauthorized person at

those sectors can cause some mishandling of the system leads to great accidents.

Hence an efficient human motion detection system is needed. Another place where

human detection needed is war fields and places where disaster occured.

Human identity is carried out using a Human live detection sensor. The

PIR sensor is used to detect the motion in any kind and will inform to microcontroller. In this project we are using GSM based wireless system for the efficient

communication. If the micro controller unit receives the detected signal, it will send a

message through GSM modem. The GPS receiver receives the Longitudinal and

latitudinal value when the system detects the movement of the human body it sends

the location details to the stations using GSM modem.

INTRODUCTION

Until well into the twentieth century, most of devices developed for measuring

distance/movements worked on the same principle; comparison of the measured distance

with the standard unit of length .Other advanced means are available now. In this project

we are implementing the detection of any type of minute movements by using a PIR

sensor. Here we are doing the live human detection. In any living body emits heats in the

form of infrared radiations which is detected by the PIR sensor. You will find many uses

for this movement detector. This type of human detection is used in some hazardous

sectors like boilers, reactors where authorized persons can only enter and also used in war

fields etc. Human detection is a essential concept in the industrial sectors. In this project

we are using GSM based wireless system for the efficient communication and to avoid

the unauthorized person involvement in the hazardous areas. The PIR sensor is used to


2/50

detect the motion in any kind and will inform to micro controller. If the micro controller

unit receives the detected signal, it will send a message through GSM Modem.

This project deals with giving intelligence to the existing security

system. In this the human identity is carried out using a Human live detection

sensor. The unique act as human attributes and can be checked out for

verification. The human live detection sensor is interfaced to the input port of the

microcontroller, which keeps track of the Identification. The GPS device getting

the longitudinal and latitudinal value of the Human place .The GPS receiver

receives the Longitudinal and latitudinal value. This setup acts as Master and

connected to slave system GSM Modem via RS 232 cable.


3/50

BLOCK DIAGRAM

MICRO

CONTROLLER

POWERSUPPLY

PIR

SENSOR

GPS

RECEIVER

TTL-RS-232TRANSCEIVER

GSM MMODEM


4/50

BLOCK DIAGRAM DESCRIPTION

PIR SENSOR

A PIR (passive infrared) detector coupled with an electric light is

now widely used for intruder protection. PIR are also available as stand-alone

units which usually have a switched output for controlling external loads. To

enable the PIR detector to work in daylight also, you have to cover the internal

light/darknes sensor (usually an LDR).The PIR detector used in this circuit reacts

to fast temperature variations caused by the movement of people or animals in an

enclosed space. All mammals radiate a certain amount of heat, and it is this that

causes local variations in temperature. The radiant heat energy occupies the

electromagnetic spectrum between light and radio waves, i.e. 0.74.300m m,which is usually called the infrared region. The radiant energy is picked up by a

Fresnel lens, at the focus of which is a double differential pyroelectric sensor. The

detector is largely unaffected by other electrical radiation. Also, it does not react

to movement outside the guarded.

Passive InfraRed sensors (PIR sensors) are electronic devices

which measure infrared light radiating from objects in the field of view. PIRs are

often used in the construction of PIR-based motion detectors, see below. Apparent

motion is detected when an infrared emitting source with one temperature, such as

a human body, passes in front of a source with another temperature, such as a

wall.

Fig.PIR sensor


5/50

All objects emit infrared radiation; see black body radiation. This

radiation (energy) is invisible to the human eye but can be detected by electronic

devices designed for such a purpose. The term 'passive' in this instance means the

PIR does not emit any energy of any type but merely sits 'passive' accepting

infrared energy through the front of the sensor, known as the sensor face. At the

core of a PIR is a solid state sensor or set of sensors, with approximately 1/4 inch

square area. The sensor areas are made from a pyroelectric material.

The actual sensor on the chip is made from natural or artificial

pyroelectric materials, usually in the form of a thin film, out of gallium nitride

(GaN), caesium nitrate (CsNO3), polyvinyl fluorides, derivatives of

phenylpyrazine, and cobalt phthalocyanine. (See pyroelectric crystals.) Lithium

tantalate (LiTaO3) is a crystal exhibiting both piezoelectric and pyroelectric

properties.

The sensor is often manufactured as part of an integrated circuit

and may be comprised of one (1), two (2) or four (4) 'pixels' comprised of equal

areas of the pyroelectric material. Pairs of the sensor pixels may be wired as

opposite inputs to a differential amplifier. In such a configuration, the PIR

measurements cancel each other so that the average temperature of the field of

view is removed from the electrical signal; an increase of IR energy across the

entire sensor is self-cancelling and will not trigger the device. This allows the

device to resist false indications of change in the event of being exposed to flashes

of light or field-wide illumination. (Continuous bright light could still saturate the

sensor materials and render the sensor unable to register further information.) At

the same time, this differential arrangement minimizes common-mode

interference; this allows the device to resist triggering due to nearby electric

fields. However, a differential pair of sensors cannot measure temperature in that

configuration and therefore this configuration is specizliaed for motion detectors.


6/50

WORKING

Human identity is carried out using a Human live detection sensor.

The PIR sensor is used to detect the motion in any kind and will inform to micro

controller. . In this project we are using GSM Modem If the micro controller unit

receives the detected signal, it will send a message through GSM modem. The

GPS receiver receives the Longitudinal and latitudinal value when the system

detects the movement of the human body it sends the location details to the

stations using GSM Modem.

A PIR (passive infrared) detector coupled with an electric light is

now widely used for intruder protection. PIR are also available as stand-aloneunits which usually have a switched output for controlling external loads. To

enable the PIR detector to work in daylight also, you have to cover the internal

light/darknes sensor (usually an LDR).The PIR detector used in this circuit reacts

to fast temperature variations caused by the movement of people or animals in an

enclosed space. All mammals radiate a certain amount of heat, and it is this that

causes local variations in temperature. The radiant heat energy occupies the

electromagnetic spectrum between light and radio waves, i.e. 0.74.300m m,

which is usually called the infrared region. The radiant energy is picked up by a

Fresnel lens, at the focus of which is a double differential pyroelectric sensor. The

detector is largely unaffected by other electrical radiation. Also, it does not react

to movement outside the guarded.

The GPS device getting the longitudinal and latitudinal value of

the Human place .The GPS receiver receives the Longitudinal and latitudinal

value. This setup acts as Master and connected to slave system GSM modem via

RS 232 cable. The Master detects the movement of the human body& place and

sends a signal to slave via data port. Once slave receives the signal it will send a

SMS to the number which is already stored on that. The live body sensor is the

special type of sensor. This sensor has two Elements. Naturally the passive

infrared radiation is the one type of rays, which are always emitting from the live


7/50

bodies that is human bodies. These rays will be received by the sensor elements.

If there is a variation between the outputs of these elements due to movement the

live body, the difference between the outputs will be amplified by differentiation

amplifier. Then the signal is fed to another amplifier unit in order to amplify the

voltage level. The amplifier unit is constructed by the operational amplifier. Then

the amplified signal is given to micro controller.

The amplified signal is fed to a microcontroller. Here the

microcontroller is the flash type reprogrammable microcontroller in which we

have already programmed. When human bodies in the destroyed building due

bomb blast or earth quack, the sensor senses the radiation signal from the human

bodies; the microcontroller received the signal from the amplifier and activates

the driver circuit for alarm. The driver circuit is constructed with transistor, which

acts as switch to turn ON and turn OFF alarm. Now the alarm makes the sound

for live bodies indication.

The microcontroller circuit is connected with reset circuit, crystal

oscillator circuit,lcd circuit the reset circuit is the one which is an external

interrupt which is designed to reset the program. And the crystal oscillator circuit

is the one used to generate the pulses to microcontroller and it also called as the

heart of the microcontroller here we have used 12mhz crystal which generates

pulses upto 12000000 frequency which is converted into machine cycle frequency

when divided by 12 which is equal to 1000000hz i.e. about 10 lakhs frequency is

generated per second to find the time we have to invert the frequency so that we

get one micro second for the execution of a instruction.

Reset circuitry is used to reset the circuit. It is an input and is

active high (normally low). Upon applying a high pulse to this pin, the

microcontroller will reset and terminate all activities. This is often referred to as a

power on reset. Activating a power-on reset.Will cause all values in the registers

to be lost.Notice that the values of the pc is 0 upon reset, forcing the cpu to fetch


8/50

the first opcode from ROM memory location 0000. This means that we must

place the first line of source code in rom location 0 because that is where the cpu

wakes up and expects to find the first instruction.

HARDWARE AND SOFTWARE REQUIREMENTS

Hardware requirements:

1. Microcontroller

2. PIR sensor

3. GPS receiver

4. GSM MODEM

5. TTL-RS-232 Transceiver

6. Power supply unit

MICROCONTROLLER

The 8952 architecture consists of these specific features:

o Eight bit CPU with registers A (the accumulator) and B

o Sixteen bit program counter (PC) and Data pointer (DPTR)

o Eight bit program status word (PSW)

o Eight bit stack pointer (SP)


9/50

o Internal ROM of 8K

o Internal RAM of 28 bytes

o Sixteen input/output pins arranged as two eight-bit ports: P1 &P3

o Two sixteen bit counters T0 & T1

o Full Duplex serial data receiver/transmitter : SBUF

o Control register : TCON, TMOD, SCON, PCON, IT and IR

o Two external and three internal interrupt sources

o Oscillator and clock circuits

The programming model of 1852 is a collection of 8-bit and 16-bit registers and 8-bit

memory locations. These registers and memory locations can be made to operate using

the software instructions that arte incorporated as part of the design. The program

instructions have to do with the control of the registers and data paths that are physically

contained inside the 8951.

Each register, with the exception of the program counter, has an internal 1-byte

address assigned to it. Some registers are both bit addressable and byte addressable.

Software instructions are generally able to specify a register buy its address, its symbolic

name, of both.

All internal operations are synchronized using clock pulses. Pins XTAL 1 &

XTAL 2 are provided for connecting a resonant network to form an oscillator, Typically

a quarts crystal and capacitors are employed as shown in figure. The crystal frequency is

the basic clock frequency of the microcontroller.

The Oscillator formed by the crystal, capacitors, and on-chip inverter generates a

pulse train at the frequency of the crystal. The clock frequency f, establishes the smallest

interval of time within the microcontroller, called the pulse time P. The smallest intervalof time to accomplish any simple instruction, or part of a complex instruction however, is

the machine cycle. The machine cycle itself is made up of sic states. A state is the basic

time interval for discrete operations of the microcontroller such as fetching an opcode

byte, decoding an opcode, executing an opcode, or writing a data byte. Two oscillator

pulses define each state.


10/50

Program instructions may require one, tow or four machine cycles to be executed,

depending on the type of instruction. Instructions are fetched and executed by the

microcontroller automatically, beginning with the instruction located at ROM memory

address 0000H at the time the microcontroller is first reset.

To calculate the time any particular instruction will take to be executed, find the

number of cycles, C. The time to execute that instruction is then found by multiplying C

by 12 and dividing the product by the crystal frequency.

``T inst = C*12d/Crystal frequency

Program Counter and Data Pointer

The 8951 contains two 16-bit registers. The program counters (PC) and the data

pointer (DPTR). Each is used to hold the address of a byte in memory.

Program instruction bytes are fetched from memory locations in memory that are

addressed by the PC. Program ROM may be on the chip at address 0000H to 07FFGH.

The PC is automatically incremented after every instruction byte is fetched and may

also be altered by certain instruction.

THE DPTR register is made up of two 8-bit registers named DPH, DPL, which

are used to furnish memory addressed for internal code access.

11.1 Timing and control signals

The counters are divided into two 8-bit registers called the timer low (TL0, TL1)

and high (TH0, TH1) bytes. All counter action is controlled by sit states in the timer

mode control register (TMOD), the timer/counter register (TCON), and certain program

instructions.

TMOD is decided entirely to the two timers and can be considered to be two

duplicate 4-bit registers, each of which controls the action of one of the timers. TCON

has control bits and flags for the timers in the upper nibble, and control bits and flags for

the external interrupts in the lower nibble.

Timer counter Interrupts


11/50

The timer have been included on the chip to relieve the processor of timing and

counting chores, When the program wishes to count a certain number of internal pulses

of external events, a number is placed in one of the counters. The number represents the

maximum count less the desired count, plus 1. The counter increment from the initial

number to the maximum and the roles over to 0 on the final pulse and also sets a timer

flag. The flag condition may be rested by an instruction to tell the program that the count

has been accomplished.

Timing

If counter is programmed to be a timer, it will count the internal clock frequency

of the oscillator divided by 12d. The resultant timer clock is gated to the timer. The bit

TRX in the TCON register must be set 1 (timer run), and the gate bit in the TMOD

register must be 0, or the external pin INTX must be a 1. The counter is configured as a

timer, then the timer pulses are gated to the counter by the bit and gate bit or the external

inputs bits INTX.

Timer Modes of Operation

The timers may operate in any one of the four modes that are determined by the

mode bits, M1 and M0 in the TMOD register.

Timer Mode 0

Setting timer X mode bits to 00b in the TMOD register results in using the THX

register as an 8-bit counter and TLX as 5-bit counter, the pulse input is divided by 32d in

TL so that the TH counts the original oscillator frequency reduced by a total 384d.

Timer Mode 1


12/50

Mode 1 is similar to mode 0 except TLX is configured as a full 8-bit counter

when the mode bits are set to 01b in the TMOD. The timer flag would be set in 1311

seconds using 6MHz crystal.

Timer Mode 2

Setting the mode bits to 10b in the TMOD configures the timer to use only

the TLX counter as an 8-bit counter, THX is used to hold a value that is loaded into TLX

every time TLX overflows from FFh to 00h. The timer flag is also set when TLX

overflows. This mode exhibits an auto reload feature. TLX will count up from the

number in THX, overflow and be initialized again with the contents of THX.

Timer Mode 3

Timer 0 and 1 may be programmed to be in mode 0, 1 or 2 independently of a

similar mode for the other timer. This is not true mode 3 , the timers do not operate

independently.

If mode 3 is chosen for timer 0 placing timer 1 in mode d caused it to stop

counting, the control bit TR1 and the timer flag TF1 are the used by timer 0.

Timer 0 in mode 3 becomes tow completely separate 8 bit counters TL0 is

controlled by the gate arrangement and sets the timer flag TF0 wherever it overflows

from FFh to 00h. TH0 receives the timer clock (the oscillator divided by twelve) under

the control of TR1 only and sets the TF1 flag when it overflows.

Timer 1 may be still used in modes 0, 1 or 2, while timer 0 is in mode 3 with one

important exception no interrupts will be generated by the timer 1 while timer 0 is using

the TF! Overflow flag. Switching timer 1 to mode 3 will stop it and hold whatever count

is in timer 1. Timer 1 can be used for baud rate generation for the serial port, or any other

mode 0, 1, or 2 functions that does not depend on an interrupt (or any other use of the

TF1 flag) for proper operation.

The only difference between counting and timing is the source of the clock pulsed

to the counter. When used as a timer the clock pulses are sources from the oscillator


13/50

through the divided by twelve circuit. When used as counter, pin T0 supplies pulses to

counter 0, and pin T1 to counter 1. Changes on the input from high to low between

samples will incr4ement the counter. Each high and low s5ate of the input pulse m7st

th7s be held constant for attest one machine cycle to ensure reliable counting.

RESET

This can be considered as the ultimate interrupt as the program cannot block the

action of the voltage at the RST pin. This type of interrupt is often called non-mask able

interrupt. Unlike other interrupts, the PC is not stored for later program resumption.

Interrupt Control

The IE register holds the programmable bits can enable or disable all the interrupts as

group, or if the group is enabled, each individual interrupt source can be enabled or

disabled. The IP register bits may be set by the program to assign priorities among the

various interrupt sources so that more important interrupts can be serviced first.

DM74LS373 (D Latch and edge triggered flip flop)

The other option is to use a DM74LS374 which is not used as its enable pin is

edge triggered. This chip is used to filter out the multiplexed lower order address data bus

of the microcontroller so as to get an 8 bit address only which is provided to the external

RAM. It consists of 8 D flip flops with an ALE signal to latch the address alone. The first

output control pin is active low and thus grounded. The 11th pin is the enable pin which

has to be high in order to pass or filter in the address only from the microcontroller to be

provided to the external RAM. 74HC373. The ALE of the microcontroller is used for

latching as the pulse arrives. This IC consists of 8D flip-flops given by AD0-AD7 and 8Qoutputs given by A0-A7.Then the latch enable [LE] pin is held high, Q outputs are

latched to D inputs. It also has an output enable pin which is active low and is connected

to the output of the flip-flops. The enable pin is connected to the flip flop directly and is

active high.


14/50

The second 74HC373 is the display buffer. Here the two outputs are connected to

the header 15 connector which is the LCD display buffer. The latch enable pin is

connected to 74LS14 inverter gate which accepts the write input. Here the latch enable

pin has to be directed opposite to how the other IC pin is working in order to provide the

data from the multiplexed lower order bus of the microcontroller to the LCD display on

the transmitter side used for verification.

NOTE:

To ensure that only one device is connected to the microcontroller at a time the

higher 4 bits of the address is inserted into a 4 input NAND gate and the output of this

NAND is used to enable the decoder or demultiplexer. The same output of the NAND

gate is inverted by inputting into another NAND gate of the same chip and using it to

enable the static external RAM. Thus it makes sure that when the decoder is activated the

external RAM is not activated and vice versa.

When the decoder is activated, the next three bits of the address acts as the select

lines which help to enable either one of the sensor digital inputs into the microcontroller

or helps to act as the enable pin of the LCD connected in the transmitter side.

The setup is managed in a manner that the microcontroller connects either with the

external RAM and address latch or the decoder and demultiplexer attached to the sensor

part of the circuit.

The data read into the microcontroller is moved into the RAM as well as moved

into the SBUF for serial communication and this data is available in the TXD pin of the

microcontroller.

DM 74LS14(Hex Inverter with Schmitt Trigger Inputs)

This device contains six independent gates each of which performs

the logic INVERT function. Each input has hysteretic which increases the noise

immunity and transforms as lowly changing input signal to a fast changing, jitter free

output.


15/50

DISPLAY SECTION

An 89C52 program must interact with the outside world using input and output

devices that communicate directly with a human being. One of the most common devices

attached to an 89C52 is an LCD display. Some of the most common LCDs connected to

the 89C52 are 16*2 displays. This means 16 characters per line by 2 lines and 20

characters per line by 2 lines, respectively.

The 44780 standard requires 3 control lines as well as either 4 or 8 I/O lines for

the data bus. The used may select whether the LCD is to operate with a 4-bit data bus of

an 8-bit data bus. If a 4-bit data bus is used, the LCD will require a total of 7 data lines (3

control line plus the 4 lines for the data bus). If an 8-bit data bus I used in the LCD will

require a total of 11 data lines (3 control lines plus the 8 lines for the data bus). The three

control lines are referred to as EN, RS, and RW.

The EN line is called Enable. This control line is used to tell the LCD

that you are sending it data. To send data to the LCD, your program should first set this

line high (1) and the set the other two control lines and/or put data on the data bus. When

the other lines are completely ready, bring EN low (0) again. The 1-0 transition tells the


16/50

44780 to take the data currently found on the other control lines and on the data bus and

to treat it as a command.

The RS line is the Register Select line. When RS is low (0), the data is to be

treated as a command or special instruction (such as clear screen, position, cursor, etc.).

When RS is high (1), the data being sent is text data which should be displayed on the

screen. For example, to display the letter t on the screen you would set RS high/

The RW line is the Read/Write control line. When RW is low(0), the

information on the data bus is being written to the LCD. When RW is high (1

1), the program is effectively querying (or reading) the LCD. Only one instruction (Get

LCD status is a read command. All others are write commandsso RW will almost

always be low.

The display contains tow internal byte-wide registers, one for commands (RS=0)

and the second for characters to be displayed (RS=1). It also contains a user programmed

RAM area (the character RAM) that cab be programmed to generate any desired

character that can be formed using a dot matrix. To distinguish between these two data

areas, the hex command byte 80 will be used to signify that the display RAM address 00h

is chosen

Port 1 is used to furnish the command or data byte, and ports 3.2 to 3.4 furnish

register select (RS) and read or write (R/W) levels.

SERIAL INTERFACE

The MAX 232 is a dual driver/receiver that includes a capacitive voltage generator to

supply EIA-232 voltage levels from a single +5V supply. Each receiver converts EIA

232 inputs to 5 V TTL/CMOS levels. These receivers have a typical threshold of 1.3V

and a typical hysteresis of 0.5 V and can accept 30V inputs. Each driver converts

TTL/CMOS input levels into EIA-232 levels. It can operate up to a speed of 120 kbits per

second. It has two drivers and two receivers. It has a tolerance of 30V input levels. It

has a low supply current of around 8mA. It can be used as a battery powered system,

terminal, modem or a computer.


17/50

71


18/50

The micro controller is serially interfaced with the PC, where the PC reads the stored data

from the micro controller. The PC is serially interfaced via its COMPORT with the micro

controller by an RS232 serial data interface.

The MAX 232 contains four sections: dual charge pump DC-DC voltage converters, RS

232 drivers, RS 232 receivers and receiver and transmitter enable control inputs. The

MAX 232 has two internal charge pumps that convert +5V to +10V for RS 232 driver

operation. The first converter uses capacitor C1 to double the +5V input to +10V on C3


19/50

at the V+ output. The second converter uses capacitor C2 to invert +10V to 10V on C4

at the V- output. A small amount of power may be drawn from the +10V and 10V

outputs to power external circuitry except on MAX 225 and MAX (245-247) where these

pins are not available.

The MAX232 can be used to make both the PC and the micro controller voltage

compatible with each other. This IC can be used to interface the TTL/CMOS I/O lines

with the RS-232 I/O lines.

LCD (HD44780U)

An LCD is a common device which is used almost every day they are all around in

laptop computers ,digital clocks & watches, microwave ovens ,Cd players 7 many other

electronic devices.LCDs are common because they offer some real advantages over other

display technologies. They are thinner & lighter&draw much less power than CRTs.

There is an underlying technology that makes LCDs work. The strange

characteristics of liquid crystals have been used to create a new kind of shutter & grids of

these tiny shutters open & close to make patterns that represent numbers words or images

.


20/50

The HD44780U dot matrix LCD controller and driver LSI displays alpha

numerics, Japanese kana charas & symbols. It can be configured to drive a dot matrix

liquid crystal display under the control of a 4 or 8 bit p.Since all the functions such as

display RAM, character generator & liquid crystal driver, required 4 driving a dot matrix

LCD s are internally provided on one chip, a minimal system can be interfaced with this

controller or driver. A single HD44780U can display up to one 8 character line or two 8

character line. The HD44780U has pin function compatibility with the HD 44780U

which allows the user to easily replace an LCD II with an HD44780U.HD44780U

character generator ROM is extended to generate 20858 dot character fonts &325 10

dot

character fonts for a total of 240 different character fonts. The low power supply (2.7V-

5.5V) of the HD 44780U is suitable for any portable battery driven product requiring low

power dissipation.

LIQUID CRYSTALS

There are some substances that can exist in an odd state i.e. sort of like a liquid and sort

of like a solid .when they are in this state there molecules tend to maintain their

orientation ,like the molecules in a solid ,but also move around to different positions like

the molecules in a liquid. This means that the liquid crystals are neither solid nor liquids.NEMATIC PHASE LIQUID CRYSTAL

Just as there are many verities of solids and liquids there is also a variety of liquid

crystal substances. Depending on the temperature & the particular nature of substance

liquid crystals can be in one of the several distinct phases. Liquid crystals in the nematic

phase are the liquid crystals that make LCDs possible.

One feature of liquid crystals is that they are affected by electric current. Particular

sort of nematic liquid crystal, called twisted nematics (TN), is naturally twisted. Applying

an electric current to these liquid crystals will untwist them to varying degrees, depending

on the currents voltage.LCDs use these liquid crystals because they react predictably to

electric current in such away as to control light passage creating an LCD.there is far more

to building an LCD than simply creating a sheet of liquid crystals .


21/50

ACTIVE AND PASSIVE COMPONENTS

The other miscellaneous components used in the circuit include the passive components

such as resistors, capacitance and active components such as LED, diodes etc. The

passive components by themselves are not capable of amplifying or processing electrical

signals. They conduct current in both directions. They are explained below and are used

in our circuit as the external component to provide different functions.

RESISTORS

Resistor is an electronic component with a specified amount of resistance. Resistors

allow current conduction in either direction. They are used to control the flow of current

and to provide desired amount of voltage in the circuit. The resistance value is normally

marked on the resistor in codes using standard color bands. Tolerance is the allowed

variation of resistance value from the normal value. Value of resistors are generally

available in the market ranges from several mega ohms with tolerance of 5%, 10% and

20%.In this circuit we are using fixed resistors whose value does not change at all

CAPACITOR

A capacitor is a passive electronic circuit element. Basically capacitor consists of two

metals plates kept apart by an insulating material between the plates. It is used to store

and release charge when required. Capacitance is the measure of the strength of the

electric field surrounding the conductor. Capacitance is defined as the property of

capacitor, when opposes the sudden changes in the applied voltage. Capacitance is

measured in Farads. Capacitance can be used to change AC into stored DC like in

battery. The stored electric energy can be used to drive the operation of electric devices.


22/50

In this project ceramic and electrolytic capacitors are used for filtering and triggering

circuit for the oscillators and part of the power supply.

DIODES

Semiconductor diode is also called a P-N junction diode. It conducts current in

one direction only and is utilized in rectifiers. The P-N junction is encapsulated in plastic,

taking 2 leads out for circuit connection. The lead attached to the P-type is called the

anode and to N-type is called cathode. The diodes are operated in two modes- forward

biased and reverse biased. In this circuit, 1N4001 & 1N4007 are used.

CRYSTAL

For an exceptionally high degree of frequency stability, crystal oscillators are used. The

crystal generally used is a finely grounded water of translucent quartz (or tourmaline)

stone held between two metal plates and housed in a package of about the size of a postal

stamp. The crystal wafers are cut from the crude quartz.

The method of cutting determines the crystals natural resonant frequency and its

temperature coefficient. When the wafer is cut so that its flat surfaces are perpendicular

to its electrical axis, it is called an X-cut crystal. But if the wafer is cut so that its flat

surfaces are perpendicular to its mechanical axis, it is called Y-cut crystal.

The quartz crystal has certain properties. When mechanical stress is applied

across its two opposite phases, a potential difference is developed across them. It is called

piezo electrical effect. Conversely, when a potential difference is applied cross a crystal it

either expands or contract.

If an alternating voltage is applied, the crystal wafer is set into vibrations. The

frequency of vibration is equal to the resonant frequency of the crystal.


23/50

POWER SUPPLY CIRCUIT WITH BATTERY BACKUP

The circuit consist of step-down transformer, rectifier filter, regulator and

protection circuit .Step down transformer(230/6v,500mA) is used for reducing the supply

voltage from 230v to 6v.The 230v AC is directly given to transformer through a switch

(s1).This switch is used for switching the main supply .The o/p of the transformer will get

6v AC. That voltage is given to the bridge rectifier and it consists of four diodes. During

the + ve half cycle (d1&d3) will conduct and in the vet half cycle diodes (d2&d3) will

conduct. O/P of the rectifier will be pulsating DC for getting a pure DC output it requires

a filter circuit.

Here capacitor C1 will act as a filter. So the O/P of the capacitor will be almost pure DC.

For better performance of the circuit it requires a constant 5vDC.Ic7805 will act as a

regulator. It is having 3 pin, in that the first pin as the filter O/P & the second pin is a

common point. O/P will get from the third pin. This O/P will be constant 5v DC. When a

+5v is enter the battery will charge through Diode D5, R3.The same time D6 also will

conduct and we will get clear O/P. When I/P power are off battery will provide thesupply and D7 will conduct and we can get the o/p. capacitor C will maintain the constant

voltage across load. Switch S2 is used for switching the O/P DC voltage. Whenever the

switch is in on condition LED will blink and it will show the O/P power is available.


24/50

TRANSFORMER:

The transformers are used to increase or decrease the amplitude of an ac voltage, keeping

the frequency constant. It works on the principle of mutual conduction. A transformer

consists of two inductive coils, which are electrically separated but magnetically linked

through path of low inductance, and these coils are primary coil and secondary coil. The

two coils posses high mutual inductance. Transformers can be used t o step up or step

down. In the step up transformer, the ac voltage signal feed across the primary will get set

up in the secondary of the transformer. In step down transformer the voltage in the

primary will get reduced in the secondary of the transformer.

In the step up transformer, the number of turns of the primary is less than that of the

secondary coil of the transformer. In the step down transformer the no. of turns in the

primary coil is greater than that of the secondary coil of the transformer. The output

voltage and current of the transformer depend on the number of turns in the primary and

secondary coils and the area of cross section of the copper wire used. The primary and

secondary windings are placed in a core.

The transformer used in our project is 0- 12V AC 1 Amps. 1 Amp 12V transformer is

selected because the maximum current flowing through the circuit is less than 1 Amp.

RECTIFIER:

The main function of a diode in the rectifier circuit is to convert the AC to rippled DC.

When AC input voltage is to be rectified it is first given to the transformer and its output

is fed to the series connected diode and load RL. The output is obtained across the load.


25/50

This can be explained in such a way that during the positive half cycle of the ac input

voltage the diode is reversed biased and it will not conduct. So during the positive half

cycle of the ac input voltage, there is output across the load and during the negative half

cycle of the input, there is no output across the load.

The rectifier used in our project is full wave rectifier

Full wave rectifier:

In a full wave rectifier we utilize both the half cycles of the AC input voltage. Alternate

half cycles of the input AC voltage are inverted t give a unidirectional load current.

Full wave bridge rectifier requires 4 diodes for its operation and it avoids the need for the

centre- tapped transformer.

During the positive half cycle of the secondary voltage, the diodes D2 and D4 are

conducting and the diodes D1 and D3 are non- conducting. Therefore current flows

through the secondary winding D2, load resistance Rl and the diode D. During the

negative half cycle of the secondary voltage D1 and D3 conducts and the diodes D2 and

D4 do not conduct. The current therefore flows through the secondary winding diode D1

and D3. Load resistor Rl. In both the cases current passes through the load resistor in the

same direction. Therefore a fluctuating unidirectional voltage is developed across the

load. Rectification efficiency of the circuit is 81.2%.

The diodes used here in our project for the rectification purpose is 1N4007.

CAPACITOR:

A capacitor is a passive electronic circuit element. Basically capacitors consist of two

metal plates kept apart by an insulating material between the plates. It is used to store and

release charge when required. Capacitance is the measure of the strength of the electric


26/50

field surrounding the conductor. When a battery is connected across the capacitor it gets

charged. Capacitance is defined as the property of capacitor, which opposes the sudden

changes in the applied voltage. Capacitance is measured in Farads (F). Capacitors can be

used to change alternating voltage(AC) into stored DC like in battery. The stored

electrical energy can be used to drive the operation of electrical devices. In this project

ceramic and electrolytic capacitors are used for filtering and triggering circuit for the

oscillators and part of the power supply.

Capacitor filter:

Capacitor filter consists of a capacitor placed across the rectifier output in parallel with

the load R. the pulsating Dc voltage increases it changes the capacitor and also supplies

current to the load. At the end of the quarter cycle, the capacitor gets changed to the peak

value Vm of the rectifier voltage. Now the rectifier voltage starts to decrease. As this

occurs the capacitor discharges through the load and voltage across the capacitor

decreases. The voltage across the load will decrease only slightly because the next

voltage peak comes and recharges the capacitor. This process is repeated again and again.

If we observe the output it may be seen that very little ripple is left in the output. A much

steadier voltage can be obtained if the capacitor of large value is used. Capacitor filter is

popular because of its low cost, small size and good characteristics. In our project the

value of the capacitor is 2200 micro farad.

REGULATORS:


27/50

The LM 78XX series of three terminal regulators is available with several fixed output

voltages making them useful in a number of applications. One of these is local on- card

regulation, eliminating the distribution problems associated with single point regulation.

The voltages available allow these regulators to be used in logic systems,

instrumentation, WiFi, and other solid- state electronic equipment. Although designed

primarily as fixed voltage regulators, these devices can be used with external components

to obtain adjustable voltages and currents.

In an unregulated power supply, the output voltage changes whenever input supply

voltage or load resistance changes. It is never constant. The change in voltage from no

load to full load condition is called voltage regulation. The aim of a voltage regulated

circuit is to reduce these variations to zero or at least to the minimum possible value.

Voltage regulators comprise a class of widely used ICs. Regulator IC unit contain the

circuitry. For reference source, comparator amplifier, control device, and overload

protection all in a single IC. Although the internal construction of the IC is somewhat

different from that described for discrete voltage regulator circuits, the external operation

is much the same. IC units provide regulation of a fixed negative voltage or an adjustably

set voltage.

The regulators can be selected for operation with load currents from hundreds of milli

amperes to tens of amperes, corresponding to power ratings from milli watts to tens of

watts.

The fixed voltage regulator has an unregulated DC input voltage, Vi, applied to one of

the input terminal, a regulated output DC voltage Vo, from a second terminal, with the

third terminal connected to the ground. For a selected regulators, IC device specifications


28/50

list a voltage range over which the input voltage can vary to maintain a regulated output

voltage over a range of load current. The specification also lists the amount of output

voltage change resulting from a change in load current (load regulation) or input voltage

(line regulation).

Fixed positive voltage regulators:

The LM 78XX series is available in an aluminum TO-3 package, which allow over 1.0A

load current if adequate heat sinking is provided. Current limiting is included to limit the

peak output current to a safe value. Safe area protection for the output transistor is

provided to limit internal power dissipation. If internal power dissipation becomes too

high for the heat sinking provided, the thermal shutdown tales over preventing the IC

from overheating.

The series 78 regulators provide fixed regulated voltages from +5 to +24V. These ICs

are3designed as fixed voltage regulators and with adequate heat sinking can deliver

output currents in excess of 1A. Although these devices do not rewrite external

components, such components can be used to obtain adjustable voltages and currents.

These ICs also have internal thermal overload protection and internal short- circuit

current limiting.

These are a three- terminal voltage regulator, which has three terminals: input (Vin),

output (Vo) and a ground terminal. Since the regulator operates at a preset value, the

current limiting resistor is also internal to the device.

The main advantages of three- terminal regulators are:

Simplicity of connections to the external circuit and

Minimum of external components (in some cases no external components are required).


29/50

The capacitor, Cin, at the input side is required only when the voltage regulator is locate

more than about 5 cm from the load inductance between the supply and the regulator may

cause stability problems and high frequency oscillations. This capacitor should have low

effective series resistance. Acceptable values are generally 0.2 MF ceramic disk, 2MF or

greater or 25 MF or greater aluminium electrolytic.

The output capacitor Co may not be needed. However, this improves the regulator

response to transient changes in the load conditions. This capacitor also reduces the noise

present at regulator output.

MICROCONTROLLER PROGRAMMING PARTOnce the PCB board is manufactured and then various components are placed

accordingly and soldered with precision in the next step the the microcontroller used in

the circuit has to be programmed based on the specifications needed or provided by the

designer. This programming is done after a clear flowchart and an algorithm has been

created regarding various steps that must be done by the microcontroller in order to

enable the proper functioning of the circuit. This process must be done for both the

transmitter and the receiver side so that both work simultaneously with sync and hence

enable the proper transmission of the data from the transmitter side to the receiver side

and thus completing the wireless transmission part of the data. This data available in the

receiver side is compared with a reference value so as to decide the working of a relay

that is connected to the circuit that controls the process going on in the transmitter side.

Programming part of the microcontroller on both sides

The program typed in by the user is an assembly level language which cannot be

directly entered into the microcontroller. This assembly level program has to be

converted into a HEX file which helps in the working of the microcontroller. The

software used for this conversion is KEIL software which changes the HEX file format

into a one that is accepted by the microcontroller of the users choice. Selecting the type

of microcontroller in the beginning as the software is opened helps in loading the header

files. The assembly level program has to be rebuilt into a target file which has no errors.


30/50

If errors are present, they can be found in the listing file created by the compiler and then

corrected and rebuilt again.

An .m extension file tells various memory locations of labels and each line. It also

tells the amount of memory space used by the program

An .obj extension file provides opcodes of the program

The IC is placed in the IC holder of the programmer. The software used for

microcontroller programming is DATA I/O. Before downloading the HEX file the

memory of the chip has to be erased. Later the created HEX file is downloaded into the

chip. Based on the users choice the lock bits of the microcontroller can be set to prevent

piracy or to provide security. The flash programming is also enabled in the

microcontroller. Thus the microcontroller is programmed.

Keil C compiler

Keil development tools for the 8051 Microcontroller Architecture support every level of

software developer from the professional applications engineer to the student just

learning about embedded software development. The industry-standard Keil C

Compilers, Macro Assemblers, Debuggers, Real-time Kernels, Single-board Computers,

and Emulators support all 8051 derivatives and help you get your projects completed on

schedule. The Keil 8051 Development Tools are designed to solve the complex

problems facing embedded software developers.

PROGRAMMING LANGUAGE

Assembly language unlike the high level language programming is tied very closely to

the physical makeup of the processing chip. Assembly language is usually written in

instruction mnemonics that have been invented by the processing chip manufacturer.


31/50

Once a program has been written in mnemonics, it is translated into machine language by

a process known as assembling the program.

Reasons for selecting assembly language

Increase the speed of execution

To reduce the size of the program

Instruction set used: 89C52 instruction set

Assembler: 89C52 assembler

Source code: Assembly Language Program

Machine code: HEX File

Source code which contains source program is written in mnemonics i.e., assembly

language syntax, 8952 Assembler Package is used for editing and compiling. After

compilation we get the HEX file that contains the corresponding machine code of the

program.

INTRODUCTION TO PCB

PCB DESIGN PROCESS:

Layout design

This is the first step of PCB fabrication. The following has to be known before

starting to prepare the layout:

Physical component size, pin configuration IC and transistors, preferable PCB size, PCB

mounting method, connection termination methods and circuit function details as

maximum current and operating frequency.


32/50

Layout scale

This is selected based on the accuracy needed which can be 1:1 or 2:1 or 4:1. First

the layout is prepared on a larger scale for better precision of the circuit and then the

scale is reduced photographically. The sheet on which the layout is prepared is like a grid

or graph sheet.

PCB size:

Formula: A=K.(H+C)

Where A: area of PCB K: constant density factor=1.72 to 2

H: hardware area

C: component area

Classification of PCB boards

Boards are classified as single side PCB and double side boards.

Single side PCB boards

They are used most in entertainment electronics as the cost of manufacturing is

less. They have their print or track on only one side while the components are placed on

the other side only. Thus in order to provide a cross connection it has to be done on the

other side. It is mostly used in less complex circuit with fewer components. For more

complex circuits double side PCB preferred.

Double side PCB board

They have print on both the sides of the PCB. The size of the board is

proportional to the size of the circuit. It is usually seen that similar direction connection

are on one side while the connection that have a chance of shorting are printed on the

other side. It can be of two types. a) With plated through holes (expensive) b) without

plated through holes.

LAYOUT PROCEDURE

Make a component layout based on the component view. Then place larger

components first and fill in the gap with smaller components. The layout has to be

prepared along with the signal flow. Input and output connection components on edge of

PCB. Circuit divided to subunits with specified purposes and it should be taken care that


33/50

the spacing is uniform. When power devices are installed on the PCB heat sink along

with proper air circulation must be provided.

Layout design rule for analog PCB

All the components are mounted on one side of the PCB. Minimum spacing

between each component and component and PCB edge specification must be met.

Heavy component should be provided with additional support. Mounting of variable

passive components have to be done in such a way that adjustment of screws is made

easy. Pin configurations, polarity, ground and power supply connections to be correct.

The provisions of connections given to areas outside the board must be done along the

edge of the PCB.

Layout procedure

First a PCB layout has to be prepared from the component side with the clear

circuit diagram in mind. The larger components are to be placed first while the smaller

ones are filled into the gap. It is to be noted that components with input or output

connections should be placed near the connector. The components have to be placed in a

manner that desoldering one component does not affect the nearby component. For ease

the circuit has to be divided to sub units which have a predefined portion on the board. A

rough circuit is enough for a network operator or designer to produce a layout.

Connection pattern size and shape

The track line between two pads should be as less as possible with a minimum

allowed length of 230 mm. The ratio of pad width to track width has to be decreased in

order to provide a good solder joint.

Solderable pads

Minimum size of the pads depend on the hole size.

Pad diameter= hole diameter + (2*annular ring width) + production tolerance (0.5mm)

Hole diameter= Lead diameter + 0.5 mm

Annular ring width= 0.25mm for hole and less than 0.75mm diameter for the rest

Standard ration of signal line: power line: ground line=1:1.5:2

PCB FABRICATION


34/50

The size and type of the PCB used depends on the type of IC used in the circuit as

well as the conductor length and spacing between the signal conductors which helps to

know the optical wave impedance of the conductor line. This in turn helps to know the

minimum delay for the rising or falling time of a digital pulse in the circuit.

PCB manufacturing process

The circuit can be drawn on paper to modify or can be drawn on a plain copper

coated board which can be phenolic or glass epoxy (in computer chips).

Board cleaning

The base board has to be cleaned before any procedure is performed. Insufficient

cleaning might lead to difficulties in fabrication such as photo resist adhesion, uneven

photo resist film in pin holes and poor plating adhesion. They can be cleaned manually or

using machines. It requires a sink with running water, pumice powder, scrubbing brush

and a suitable tank.

Screen printing

Used for large production schemes with more than 100 PCBs. Photo printing

transfers the screen pattern to the board surface. It has the capability to produce fine

tracks with less error and high reliability. The screen is stretched and put over the board

or frame and this circuit pattern in transferred photographically. Thus on the screen the

pattern appears as open pores while rest remains closed. When printing copper is

squeezed through the open pores to the board surface and form the pattern.

Etching

It can be done manually or mechanically. The board is immersed in a solution of

formic chloride and hydrochloric acid and then cleaned with soap. It is mainly done in all

subtractive PCB processes. First the etch resist is applied all over the surface and then it

is selectively remove from areas where the print was not there. It is a tough process in the

case of production of fine and precise PCB boards. It is done to remove unwanted copper

from the processed board. Etching agents or etching solution or etchants are used to this

process. Ferric chloride, cupric chloride, ammonium per sulphate acts as etching agents.

The reagents in granular form are diluted and used as it is cheaper.


35/50

Component placing

During routing interconnections it is difficult to place components based on the

layout design. In high sensitive circuits the critical components are placed first so that

critical conductors require minimum length. In less circuit components are placed based

on signal flow order so that the overall conductor length is minimized. In circuits with

less components and more connections the key components are placed first and the

remaining are placed later. The design is made to have minimum length for the

interconnections. Axial components are placed along the edge of the PCB to prevent

stress at the solder joint.

Drilling

It is done to provide mounting holes for various components using machines.

Plated through holes need superior high speed drilling machines which are expensive, but

these machines are used by all professional PCB manufacturers. It has become tough due

to component miniaturization. Hole sizes are specified in the layout based on the

component lead diameter.

Soldering

The process done in order to join metal parts with the help of molten metal

(solder).The temperature to melt solder is set below the melting point of the metal leads.

The solder wets and alloys with the base material and then by capillary action it is sucked

into the gap between the metal lead and the board. This forms the metallurgical bond

between the joint parts. Before soldering the position at which the joint has to be soldered

must be fixed. The surface must be wet with molten solder and the solder must be

allowed to cool down and solidify. When soldering an auxiliary medium called FLUX is

used in order to increase the wetting and the flow property of the solder. Different

methods are there for soldering: iron soldering, torch soldering, mass soldering, electrical

soldering, furnace soldering etc. Soldered joints affect the performance and the reliabilityof the circuit. It is taken care that the leads are cut before soldering to protect or cover it

and thus preventing rusting. The soldered PCB might have many contaminants that have

to be cleaned as it has a drastic effect on the functioning of the circuit.


36/50

Properties of flux

It provides a liquid cover over the materials and also provides air in order to let

the solder cool down. It should be able to dissolve the oxides on the metal surface andcarry unwanted elements away. It should remove complete residues after soldering.

Corrosion resistant coating

If the board is unprotected there is high chance of formation of copper oxide over

the board which might affect the performance of the board. This is prevented by aninsulator coating or varnish.

Cleaning

The surface of the board might have oxides, greases and oil. These have to be

removed by this process. First it has to be cleaned with cotton wool soaked in

trichloroethylene. Then it has to be dipped in 10% HCL solution at room temperature and

then scrubbed with powder. Rinse with chlorine free water. If the wetting on the surface

is uniform it has been cleaned well.

Thus above explanations provide a detailed explanation of how layout is prepared

and the PCB board is manufactured industrially.

INTRODUCTION


37/50

The global Positioning System is the most reliable navigation system presently

available. The navigation data provided by the system is highly accurate and this data is

used for the display purpose. Atmel 89C52 is one of the most component micro controller

chips available in the market today. The flexibility in addressing the memory locations

and the enhanced instruction set enables the processor to perform complicated operations.

Atmel 89C52 is one of the most competent microcontroller chips available in market

today. The flexibility in addressing the memory locations and the enhanced instruction

set enables the processor to perform complicated operations. The advantage of both these

has been optimally combined for the development and implementation of our project.

GLOBAL POSITIONING SYSTEM

The Global Positioning System (GPS) is a world wide radio-navigation system

formed from a constellation of 24 satellites and their ground stations. GPS uses these

manmade stars as reference points to calculate positions accurate to a matter of meters.

In fact, with advanced forms of GPS measurements up to a centimeter can be made. In a

sense it is like giving every square meter on the planet q unique address. GPS receivers

have peen miniaturized to just a few integrated circuits and so are becoming veryeconomical. And that makes the technology accessible to virtually everyone. These days

GPS is finding its way into cars, boats, planes, construction equipment, movie making

gear, farm machinery, even laptop computers.

Heres how GPS works in five logical steps:

o The basis of GPS is Triangulation from satellites.

o To Triangulate a GIS received measures distance using travel time of signals.

o To measure travel time GPS needs very accurate timing.(Atomic clock)

o Along with distance, the exact location of the satellites in space need to be known.

o Finally any delays the signal experiences as it travels through the atmosphere

should be corrected.


38/50

GPS is funded by and controlled by the U. S. Department of Defense (DOD).

While there are many thousands of civil users of GPS world-wide, the system was

designed for and is operated by the U. S. military. GPS provides specially coded satellite

signals that can be processed in a GPS receiver, enabling the receiver to compute

position, velocity and time. Four GPS satellite signals are used to compute positions in

three dimensions and the time offset in the receiver clock.

Space Segment

The Space Segment of the system consists of the GPS satellites. These space

vehicles (SVs) send radio signals from space. The nominal GPS Operational

Constellation consists of 24 satellites that orbit the earth in 12 hours. There are often

more than 24 operational satellites as new ones are launched to replace older satellites.

The satellite orbits repeat almost the same ground track (as the earth turns beneath them)

once each day. The orbit altitude is such that the satellites repeat the same track and

configuration over any point approximately each 24 hours (4 minutes earlier each day).

There are six orbital planes (with nominally four SVs in each), equally spaced (60

degrees apart), and inclined at about fifty-five degrees with respect to the equatorial

plane. This constellation provides the user with between five and eight SVs visible from

any point on the earth.

1.2 Control Segment

The Control Segment consists of a system of tracking stations located around the

world. The Master Control facility is located at Schriever Air Force Base (formerly

Falcon AFB) in Colorado. These monitor stations measure signals from the SVs which

are incorporated into orbital models for each satellites. The models compute precise

orbital data (ephemeris) and SV clock corrections for each satellite. The Master Controlstation uploads ephemeris and clock data to the SVs. The SVs then send subsets of the

orbital ephemeris data to GPS receivers over radio signals.


39/50

1.3 User Segment

The GPS User Segment consists of the GPS receivers and the user community.

GPS receivers convert SV signals into position, velocity, and time estimates. Four

satellites are required to compute the four dimensions of X, Y, Z (position) and Time.

GPS receivers are used for navigation, positioning, time dissemination, and other

research. Navigation in three dimensions is the primary function of GPS. Navigation

receivers are made for aircraft, ships, ground vehicles, and for hand carrying by

individuals. Precise positioning is possible using GPS receivers at reference locations

providing corrections and relative positioning data for remote receivers. Surveying,

geodetic control, and plate tectonic studies are examples. Time and frequency

dissemination, based on the precise clocks on board the SVs and controlled by the

monitor stations, is another use for GPS. Astronomical observatories,

telecommunications facilities, and laboratory standards can be set to precise time signals

or controlled to accurate frequencies by special purpose GPS receivers. Research projects

have used GPS signals to measure atmospheric parameters.

2. STANDARD POSITIONING SERVICE (SPS)

Civil users worldwide use the SPS without charge or restrictions. Most receivers

are capable of receiving and using the SPS signal. The SPS accuracy is intentionally

degraded by the DOD by the use of Selective Availability.

SPS Predictable Accuracy

o 100 meter horizontal accuracy

o 156 meter vertical accuracy

o 340 nanoseconds time accuracy

These GPS accuracy figures are from the 1999 Federal Radio navigation Plan. The

figures are 95% accuracies, and express the value of two standard deviations of radial

error from the actual antenna position to an ensemble of position estimates made under

specified satellite elevation angle (five degrees) and less than six conditions. For


40/50

horizontal accuracy figures 95% is the equivalent of 2drms (two-distance root-mean-

squared), or twice the radial error standard deviation. For vertical and time errors 95% is

the value of two-standard deviations of vertical error or time error. Receiver

manufacturers may use other accuracy measures. Root-mean-square (RMS) error is the

value of one standard deviation (68%) of the error in one, two or three dimensions.

Circular Error Probable (CEP) is the value of the radius of a circle, centered at the actual

position that contains 50% of the position estimates. Spherical Error Probable (SEP) is

the spherical equivalent of CEP, that is the radius of a sphere, centered at the actual

position, that contains 50% of the three dimension position estimates. As opposed to

2drms, drms, or RMS figures, CEP and SEP are not affected by large blunder errors

making them an overly optimistic accuracy measure. Some receiver specification sheets

list horizontal accuracy in RMS or CEP and without Selective Availability, making those

receivers appear more accurate than those specified by more responsible vendors using

more conservative error measures.

3. GPS SATELLITE SIGNALS

The SVs transmit two microwave carrier signals. The L1 frequency (1575.42

MHz) carries the navigation message and the SPS code signals. The L2 frequency

(1227.60 MHz) is used to measure the ionosphere delay by PPS equipped receivers.

Three binary codes shift the L1 and/or L2 carrier phase. The C/A Code (Coarse

Acquisition) modulates the L1 carrier phase. The C/A code is a repeating 1 MHz Pseudo

Random Noise (PRN) Code. This noise-like code modulates the L1 carrier signal,

spreading the spectrum over a 1 MHz bandwidth. The C/A code repeats every 1023 bits

(one millisecond). There is a different C/A code PRN for each SV. GPS satellites are

often identified by their PRN number, the unique identifier for each pseudo-random-noise

code. The C/A code that modulates the L1 carrier is the basis for the civil SPS. The P-Code (Precise) modulates both the L1 and L2 carrier phases. The P-Code is a very long

(seven days) 10 MHz PRN code. In the Anti-Spoofing (AS) mode of operation, the P-

Code is encrypted into the Y-Code. The encrypted Y-Code requires a classified AS

Module for each receiver channel and is for use only by authorized users with

cryptographic keys. The P (Y)-Code is the basis for the PPS. The Navigation Message


41/50

also modulates the L1-C/A code signal. The Navigation Message is a 50 Hz signal

consisting of data bits that describe the GPS satellite orbits, clock corrections, and other

system parameters.

4. GPS DATA

The GPS Navigation Message consists of time-tagged data bits marking the time

of transmission of each subframe at the time they are transmitted by the SV. A data bit

frame consists of 1500 bits divided into five 300-bit subframes. A data frame is

transmitted every thirty seconds. Three six-second subframes contain orbital and clock

data. SV Clock corrections are sent in subframe one and precise SV orbital data sets

(ephemeris data parameters) for the transmitting SV are sent in subframes two and three.

Subframes four and five are used to transmit different pages of system data. An entire set

of twenty-five frames (125 subframes) makes up the complete Navigation Message that is

sent over a 12.5 minute period. Data frames (1500 bits) are sent every thirty seconds.

Each frame consists of five subframes. Data bit subframes (300 bits transmitted over six

seconds) contain parity bits that allow for data checking and limited error correction.

Clock data parameters describe the SV clock and its relationship to GPS time. Ephemerisdata parameters describe SV orbits for short sections of the satellite orbits. Normally, a

receiver gathers new ephemeris data each hour, but can use old data for up to four hours

without much error. The ephemeris parameters are used with an algorithm that computes

the SV position for any time within the period of the orbit described by the ephemeris

parameter set.

5. DIFFERENTIAL GPS (DGPS) TECHNIQUES

The idea behind all differential positioning is to correct bias errors at one location

with measured bias errors at a known position. A reference receiver, or base station,

computes corrections for each satellite signal. Because individual pseudo-ranges must be

corrected prior to the formation of a navigation solution, DGPS implementations require


42/50

software in the reference receiver that can track all SVs in view and form individual

pseudo-range corrections for each SV. These corrections are passed to the remote, or

rover, receiver which must be capable of applying these individual pseudo-range

corrections to each SV used in the navigation solution. Applying a simple position

correction from the reference receiver to the remote receiver has limited effect at useful

ranges because both receivers would have to be using the same set of SVs in their

navigation solutions and have identical GDOP terms (not possible at different locations)

to be identically affected by bias errors.

6. THE BIG IDEA GEOMETRICALLY

Suppose the distance of an object from a satellite is found to be 11,000 Miles.

Knowing this narrows down all the possible locations the object could be in the whole

universe to the surface of a sphere that is centered on the satellite and has a radius of

11,000 miles. Next the distances to as second satellite is measured and suppose it is found

to be 12,000 miles. This means that the object is not only on the first sphere but also on a

sphere that is 12,000 miles from the second satellite Or in other words the object is

somewhere on the circle where the two spheres intersect.If another measurement from third satellite is made and found out to be 13,000

Miles, the position is further narrowed down, to the two points sphere the 13,000 mile

sphere cuts through the circle thats the intersection of the first t2wo spheres. So by

ranging from three satellites, the position of the object can be narrowed down to just two

points in space. The decision about the true location is made on the basis of a fourth

measurement. But usually one of the two points is a ridiculous answer (either too far

from Earth) or moving at an impossible velocity and can be rejected without a

measurement.


43/50

7. BASIC FUNCTIONS

o Location-Determining a basic position

o Navigation-Getting from one location to another

o Tracking-Monitoring the movement of people and things

o Mapping-Creating maps of the worlds

o Timing-Bringing precise timing to the world.

7.1 Navigation

GPS products use what is called "straight line" navigation. The units, when

commanded to navigate to a waypoint, draw a straight line from their present position

to the destination waypoint. The straight line represents the shortest, most direct route

to the waypoint. It does not take into account any obstacles in the path (on land, in the

air or in the water). Consequently, it may be necessary in some situations to record

interim waypoints that alter the course to navigate around obstacles. These additional

mini segments of the journey will each represent straight line routes. Since GPS

products use straight line navigation, it is necessary to use a waypoint at each placeyou need to turn when you are navigating around an obstacle such as a cliff, or

navigating down a highway or river channel. By connecting each of these waypoints

in a chain, you form a "Route". This provides the automatic capability to navigate

through several waypoints in order, without having to manually recall another

waypoint in the unit. Once programmed into a GPS unit, a route provides the option

of navigating forward through the waypoints, or navigating in reverse in order to go

either direction through the route.

7.2 Tracking

Tracking is determining 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


44/50

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 analyzing

the track later, using customized software.

Jupiter Global Positioning System (GPS) module is a single board, 12 parallel-

channel receiver intended as a component for an Original Equipment Manufacturer

(OEM) product. The receiver continuously tracks all satellites in view and provides

accurate satellite Positioning data. Jupiter is designed for high performance and

maximum flexibility in a wide range of OEM configurations including handheld, panel

mounts, sensors, and in-vehicle automotive products.

The highly integrated digital receives uses the Zodiac chipset composed of two

custom SIRF devices: the Gemini/Pisces MonoPac and the Scorpio Baseband Processor

(BP). These tow custom chips, together with memory devices and minimum of external

components, from a complete low-power, high-performance GPS receiver solution for

OEMs. Configuration allows the OEM to design for multi-voltage operation, SIRFs.

Hardware Accelerator device (CX11239), or dead reckoning navigation that uses vehicle

sensors in the absence of GPS signals. The Jupiter receiver decodes and processes

signals from all visible GPS satellites. These satellites, in various orbits around the

Earth, broadcast radio frequency (RF) ranging codes, timing information, and navigation

data messages.

The receiver uses all available signals to produce a highly accurate navigation

solution that can be used in a wide variety of end product applications. This solution is

relatively immune to the position jumps induced by blockage that can occur in receivers

with fewer channels.

Jupiter GPS Receiver


45/50

NAVMANs Jupiter Global Positioning System (GPS) module is a singleboard, 12

parallel-channel receiver intended as a component for an Original Equipment Manufacturer

(OEM) product. The receiver continuously tracks all satellites in view and provides accurate

satellite positioning data. Jupiter is designed for high performance and maximum flexibility in a

wide range of OEM configurations including handhelds, panel mounts, sensors, and in-vehicle

automotive products.

The highly integrated digital receiver uses the Zodiac chipset composed of two

custom SIRF devices: the Gemini/Pisces MonoPac and the Scorpio Baseband

Processor (BP). These two custom chips, together with memory devices and a minimum

of external components, form a complete low-power, high-performance GPS receiver

solution for OEMs. Configurations allow the OEM to design for multi-voltage operation,

SIRF's Hardware Accelerator device (CX11239), or dead reckoning navigation that uses

vehicle sensors in the absence of GPS signals. Each configuration provides up to three

options for different types of antenna connectors. The Jupiter receiver decodes and

processes signals from all visible GPS satellites. These satellites, in various orbits around

the Earth, broadcast radio frequency (RF) ranging codes, timing information, and

navigation data messages. The receiver uses all available signals to produce a highly

accurate navigation solution that can be used in a wide variety of end productapplications. This solution is relatively immune to the position jumps induced by

blockage that can occur in receivers with fewer channels.

NMEA-0183 FORMAT

GPS receiver communication is defined within this format. Most computer

programs that provide real time position information understand and except data to be in

NMEA format. This data includes the complete PVT (position, velocity, time) solution

computed by the GPS receiver. The idea of NMEA is to send a line of data called a

sentence that I totally self-contained and independent from other sentences. All of the


46/50

standard sentences have a two-letter prefix that defines the device that uses that sentence

type, (For GPS receivers the prefix is GP.) which is followed by a three-letter sequence

that defines the sentence contents,

Each sentence begins with a $ and ends with a carriage return/line feed sequence

and can be no longer that 80 characters of visible text (plus the line terminators). The data

is contained within this single line with data items separated by commas. The data itself

is just ASCII text and may extend over multiple sentences in certain specialized instances

but is normally fully contained in one variable length sentence. The data may carry in the

amount of precision contained in the message. For example time might be indicated to

decimal parts of a second or location may be show with 3 or even 4 digits after the

decimal point. Programs that read the data should only use the commas to determined the

field boundaries and not depend on column positions. There is a provision for a

checksum at the end of each sentence, which may or may not be checked by the unit that

reads the data. The checksum field consists of a * and tow hex digits representing the

exclusive OR of all characters between, but not including, the $ and *. A checksum is

required on some sentence. The general format of NMEA sentence is given below.

HARDWARE CONNECTION

The hardware interface for GPS units is designed to meet the NMEA

requirements. They are also compatible with most computer serial ports using RS232

protocols, however strictly speaking the NMEA standard is not RS232. They recommend

conformance to E1A-422. The interface speed can be adjusted on a some models but the

NMERA standard is 4800 baud with 8 bits of data, no parity, and one stop bit. All units

that support NMEA should support this speed. Note that, at a baud rate of 4800, you caneasily send enough data to more than fill a full second of time. For this reason some units

only send updates every two seconds or may send some data every second while

reserving other data to be sent. In addition some units may send data a couple of seconds

old while other units may send data that is collected within the second it is sent.

Generally time is sent some field within each second so it is pretty easy to figure out what


47/50

a particular GPS is doing. Some sentences may be sent only during a particular action of

the receiver such as while following a route while other receivers may always send the

sentences and just null out the values. Other difference will be noted in the specific data

description defined later in the text.

At 4800 baud you can only send 480 characters in one second. Since an NMEA

sentence can be as long as 82 characters you can be limited to less than 6 different

sentences. The actual limit is determined by the specific sentences used, nut this shows

that it is easy to overrun the capabilities if you want rapid sentence response. NMEA is

designed to run as a process in the background spitting our sentences which are then

captured as needed by the using program. Some programs cannot do this and these

programs will sample the data stream, then use the data for screen display, and then

sample the data again. Depending on the time needed to use the data there can easily be a

lag of seconds in the responsiveness to changed data.

The NMEA standard has been around for many years (1983) and has undergone

several; revisions. The protocol has changed and the number and types of sentences may

be different depending on the decision. Most GPS receivers understand the standard

which is called 0183 version 2. This standard dictates a transfer rate of 4800 baud. Some

receivers also understand older standards. The oldest standard was 0180 followed by

0182 which transferred data at 1200 baud. An earlier version of 0183 called version 1.5

is also understood by some receivers. Some Garmin units and other brands can be set to

9600 for NMEA output or even higher but this is only recommended if you have

determined that 4800 works ok and then you can try to set it faster. Setting it to run as

fast as you can improve the responsiveness of the program.

In order to use the hardware interface you will need a cable. Generally the cable

is unique to the hardware model so you will need a cable made specifically for the brand

and model of the unit you own. Some of the latest computers no longer include a serial

port but only a USB port. Most GPS receivers will work with Serial to USB adapters and

serial ports attached via the pcmcia (pc card) adapter. For general NMEA use with a GPS

receiver you will only need two wires in the cable, data out from the GPS and ground. A

third wire, Data in, will be needed if you expect the receiver to accept data on this cable

such as to upload way points or send DGPS data to the receiver.


48/50

GPS receivers may be used to interface with other NMEA devices such as

autopilots, fish binders, or even other GPS receivers. They can also listen to Differential

Beacon Receivers that can send data using the RTCM SC-104 standard. This data is

consistent with the hardware requirements for NMEA in out data.

ADVANTAGES

1. Easy convenience to handle

2. Manual error in security is nullified

3. Low cost to design the circuit the live body sensor is easily available

4. Maintenance of the circuit is good

5. By using this microcontroller IC we can create many more control to the

appliances

6. Reliability

7. compatibility


49/50

APPLICATIONS

1. For homes

2. For industrial security

3. For human detection in war fields

4. It is mostly applied in the medical field and it is good thing for the blind

people

5. It is mainly applied in the automobile industry to find the distance of the

car while going reverse

FUTURE WORKThe sensing transceiver section is to be mounted on a wireless remote

controlled vehicle. The vehicle can be controlled by a PC with the help ofGSM Modem.

The control unit in sensing section controls the vehicle direction according to the

commands given from PC which is present in the receiver section by using GSM Modem.


50/50

As control unit AT89C52 microcontroller is used. GSM Modem is interfaced to PC

through serial communication using MAX 232 level converter with the help of a software

C#.net. Different directions of the vehicle are controlled by giving instructions to the

vehicle with the help of data given to the PC.

live human detection . .

Documents

Transcript of live human detection . .