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Remote Controlled Metal Detecting Robot with

Remote Image Transmission

Mini-project

Submitted in partial fulfillment of the requirements for the award of the degreeof

BACHELOR OF TECHNOLOGY

In

Electronics and Communication Engineering

By

D.SPARSHA (07D21A0443)

G.VANDANA (07D21A0455)

Under the guidance of

Mr. S. Bhargav Kumar.

Assistant Professor

Department of Electronics & Communication Engineering

SRIDEVI WOMENS ENGINEERING COLLEGE

(Affiliated to Jawaharlal Nehru Technological University, Hyderabad)

V.N.PALLY, GANDIPET, R.R.DIST-500 075

June 2010

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SRIDEVI WOMENS ENGINEERING COLLEGE

(Affiliated to Jawaharlal Nehru Technological University, Hyderabad)

V.N.PALLY, GANDIPET, R.R.DIST-500 075

Department of Electronics & Communication Engineering

BONAFIDE CERTIFICATE

Certified that the project Remote Controlled Robot with Remote Image Transmission is

the bonafide work ofD.SPARSHA (07D21A0443) and G.VANDANA (07D21A0455), who carried out

the project under my supervision from May to June in partial fulfillment of the requirements for the

award of B.Tech Electronics &Communication Engineering to Jawaharlal Nehru TechnologicalUniversity, Hyderabad.

Certified further, that to the best of my knowledge the work reported here in does not form part

of any dissertation on basis of which a degree was conferred on an earlier occasion on this or any other

candidate.

Internal Guide Head of the DepartmentMr.S.Bhargav Kumar. Dr.Y. RAJASREE

Assistant Professor Professor & HOD

Department of ECE Department of ECE

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DECLARATION

The project entitled REMOTE CONTROLLED METAL DETECTING ROBOT WITH

IMAGE TRANSMISSION is a record of the bonafide work undertaken by us towards partial

fulfillment of the award of Degree ofBachelor of Technology. The results in this project work have not

been submitted to any other University or Institute for the award of any Degree or Diploma.

D.SPARSHA (07D21A0443)

G.VANDANA (07D21A0455)

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ABSTRACT

Path Finder was sent to Mars in 1998. This was achievement a great which detected the secrets

of Mars. This project deals with RF controlled robot. This robot prototype for the Path Finder.

This robot is controlled by a RF remote. This can be moved forward and reverse direction using

geared motors of 60RPM. Also this robot can take sharp turnings towards left and right directions. This

project uses AT89S52 MCU as its controller. A high sensitive induction type metal detector is designed

using colpitts oscillator principle and fixed to this robot. Also a wireless camera with voice is interfaced

to the kit.

When the robot is moving on a surface, the system produces a beep sound when metal is

detected. This beep sound will be transmitted to remote place. Simultaneously the images around the

robot will be transmitted to remote place. User can monitor the images and metal detection alarms on

Television.

The RF modules used here are STT-433 MHz Transmitter, STR-433 MHz Receiver, HT640 RF

Encoder an HT648 RF Decoder. he three switches are interfaced to the RF transmitter through RF

Encoder. The encoder continuously reads the status of the switches, passes the data to the RF transmitter

and the transmitter transmits the data.

This project uses 9V battery. This project is much useful for mines detection and surveillance

applications

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ACKNOWLEDGEMENT

First and foremost, our sincere thanks to Prof. Y. RAJASREE, Principal and Head of the

department of Electronics and Communication Engineering, Sridevi Womens Engineering College,

V.N.Pally, Hyderabad for providing this opportunity to carry out the present project work and for her

encouragement and advice during the course of this work.

We indebted to our internal project guide Mr.S.BHARGAV KUMAR, Assistant Professor of

Electronics and Communication Engineering, for his excellent guidance, constant inspiration and

encouragement in the completion of this dissertation.

We would like to express our thanks to all the Faculty members, Staff of Department of

Electronics & Communication Engineering, who have rendered valuable help in making this project a

successful one.

D.SPARSHA

G.VANDANA

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LIST OF TABLES

Table No Name of the Table Page No

3.1. Pin Description of HT640L Encoder 10

3.2 Pin Description of HT648L Decoder 12

4.1. Alternate Functions of port 3 15

5.1. Operation of H-Bridge 17

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LIST OF FIGURES

Figure No Name of the Figure Page No

3.1 Regulated Power Supply 5

3.2 Full Wave Bridge Rectifier 6

3.3 Circuit Diagram and respective output

Waveforms of Capacitive Filter 6

3.4 RF Transmitter STT-433MHz 7

3.5 Transmitter circuit 7

3.6 HT640 Encoder 9

3.7 RF Receiver STR-433MHz 10

3.8 Pin Diagram of RF Receiver STR-433MHz 11

3.9 HT648L Decoder 12

4.1 Block Diagram of AT89C51 14

4.2 Pin Diagram of AT89C51 15

5.1 Graphical Representation of H-Bridge 16

6.1 Metal Detecting circuit 18

7.1 Block Diagram of RF Transmitter (Remote) 20

7.2 Block Diagram of RF Receiver (Remote) 21

10.1 RF Receiver Section (Robot) 28

10.2 RF Transmitter Section (Remote) 28

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INDEX

CHAPTER TOPIC PAGE NO

1 PROJECT OVERVIEW 1

2 WIRELESS COMMUNICATION 2

2.1. Radio Frequency-its necessity 2

2.1.1. Brief Description of RF 2

2.1.2. Properties of Radio Frequency 3

3 REQUIREMENTS FOR RF COMMUNICATION 4

3.1 Power Supply 4

3.2 Regulated Power Supply 4

3.3 Diode Rectifier- Full wave bridge rectifiers 5

3.4 Capacitive Filter 6

3.5 RF Transmitter STT-433MHz 7

3.5.1. About the Transmitter 8

3.5.2. Features 8

3.5.3. Pin Description 8

3.6 Basic Application circuit of HT640 Encoder 9

3.7 RF Receiver STR-433MHz 10

3.7.1. Pin Description 11

3.8 Basic Application circuit of HT648L Decoder 12

4 MICROCONTROLLER 13

4.1. General Description 13

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4.1.1 Features of ATMEL 89C51 Microcontroller 13

4.1.2 Block Diagram ATMEL 89C51 Microcontroller 14

4.1.3 Pin Diagram ATMEL 89C51 Microcontroller 15

4.1.4 Pin Description of ATMEL 89C51 Microcontroller 15

5 H-BRIDGE 17

6 METAL DETECTOR 19

7 WIRELESS CAMERA FOR IMAGE TRANSMISSION 20

7.1. RF Transmitter (Remote) Block Diagram 20

7.2. RF Receiver (Remote) Block Diagram 21

8 WORKING OF THE PROJECT 22

8.1. RF Transmitter (Remote) 22

8.2. RF Receiver (Robot) 23

9 PROGRAMMING THE FLASH (CODE) 25

9.1. Programming Algorithm 25

9.2. Project Code 26

10 RESULTS 28

ADVANTAGES AND DISADVANTAGES 29

LIMITATIONS 30

APPLICATIONS 31

CONCLUSIONS 32

REFERENCES 33

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CHAPTER 1

PROJECT OVERVIEW

The aim of this project is to control the operation of movement of a remote controlled robot to

detect metals and to view the images surrounding the robot.

The main objectives of this project are to use radio frequency bands.

The movement of robot is controlled by the transmission of signals through air.

The receiver senses these signals from the air..

This mini project makes use of the transmitter and receiver at 433MHz that is available at low

cost hence making it very complicated.

The Radio Frequency based control proves to be more advantageous compared to the Infrared

Red based control that limits the operating range to only a few meters of distance.

When the robot is moving on a surface, the system produces a beep sound when metal is

detected. This beep sound will be transmitted to remote place. Simultaneously the images around

the robot will be transmitted to remote place. User can monitor the images and metal detection

alarms on Television.

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CHAPTER2

WIRELESS COMMUNICATION

Wireless communication, as the term implies, allows information to be exchanged between two

devices without the use of wire or cable. A wireless keyboard sends information to the computer without

the use of a keyboard cable; a cellular telephone sends information to another telephone without the use

of a telephone cable. Changing television channels, opening and closing a garage door, and transferring

a file from one computer to another can all be accomplished using wireless technology. In all such cases,

information is being transmitted and received using electromagnetic energy, also referred to as

electromagnetic radiation. One of the most familiar sources of electromagnetic radiation is the sun; other

common sources include TV and radio signals, light bulbs and microwaves.

2.1. Radio Frequency-its necessity

Radio frequency is a frequency or rate of oscillation within the range of about 3Hz to 300 GHz.

This range corresponds to frequency of alternating current electrical signals used to produce and detect

radio waves.Since most of this range is beyond the vibration rate the most mechanical systems can

respond to, RF usually refers to oscillations in electrical circuits. RF is widely used because it does not

require any line of sight, less distortions and no interference. Examples include, Cordless and cellular

telephone, radio and television broadcast stations, satellite communications systems, and two-way radio

services all operate in the RF spectrum.

2.1.1. Brief Description of RF

Radio frequency (abbreviated RF) is a term that refers to alternating current (AC) having

characteristics such that, if the current is input to an antenna, an electromagnetic (EM) field is generated

suitable for wireless broadcasting and/or communications. These frequencies cover a significant portion

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of the electromagnetic radiation spectrum, extending from nine kilohertz (9 kHz),the lowest allocated

wireless communications frequency (it's within the range of human hearing), to thousands of

gigahertz(GHz).

When an RF current is supplied to an antenna, it gives rise to an electromagnetic field that

propagates through space. This field is sometimes called an RF field; in less technical jargon it is a

"radio wave." Any RF field has a wavelength that is inversely proportional to the frequency.

As the frequency is increased beyond that of the RF spectrum, EM energy takes the form of

infrared (IR), visible, ultraviolet (UV), X rays, and gamma rays. ), X rays, and gamma rays. Many types

of wireless devices make use of RF fields.Some wireless devices operate at IR or visible-light

frequencies, whose electromagnetic wavelengths are shorter than those of RF fields.

2.1.2. Properties of Radio Frequency

Electrical currents that oscillate at RF have special properties not shared by direct current

signals:

1. One such property is the ease with which it can ionize air to create a conductive path through

air. This property is exploited by 'high frequency' units.

2. Another special property is an electromagnetic force that drives the RF current to the surface of

conductors, known as the skin effect.

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CHAPTER 3

REQUIREMENTS FOR RF COMMUNICATION

RF communication is required for the transmission of radio waves from RF transmitter (remote)

to RF receiver (robot) to enable the movement of the robot in this project. The basic requirements for the

RF communication used in this project are as follows:

Power supply

RF Transmitter

RF Receiver

Encoder and Decoder

Microcontroller

3.1 Power Supply

The input to the circuit is applied from the regulated power supply. The a.c. input i.e., 230V from

the mains supply is step down by the transformer to 12V and is fed to a rectifier. The output obtained

from the rectifier is a pulsating d.c voltage. So in order to get a pure d.c voltage, the output voltage from

the rectifier is fed to a filter to remove any a.c components present even after rectification. Now, this

voltage is given to a voltage regulator to obtain a pure constant dc voltage.

3.2Regulated Power Supply

A variable regulated power supply, also called a variable bench power supply, is one where you

can continuously adjust the output voltage to your requirements. Varying the output of the power supply

is the recommended way to test a project having doubled checked parts placement against0* circuit

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drawings and the parts placement guide. Most digital logical circuits and processors need a 5 volt power

supply . to use these parts we need to build a regulated 5 volt source . Usually you start with an

unregulated power supply ranging from 9 volts to 24 volts DC. To make a 5 volt power supply, we use a

LM7805 voltage regulator IC (Integrated circuit) . the IC is shown below .

Figure 3.1: Regulated Power Supply

The LM7805 is simple to use. you simply connect the positive lead of your unregulated DC

power supply (anything from 9 VDC to 24 VDC ) to the Input pin , connect the negative lead to the

Common pin and then when you turn on the power , you get a 5 volt supply from the Output pin.

3.3 Diode rectifier- Full wave bridge rectifier

The need for a centre tapped power transformers is eliminated in the bridge rectifier .it contains

four diodes D1 , D2 , D3 and D4 connected to from bridge as shown below.

Figure 3.2: Full wave bridge rectifier

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The a. c. supply to be rectified is applied to the diagonally opposite ends of the bridge through

the transformer. Between other two ends of the bridge , the load resistance RL is connected .

3.4 Capacitor Filter

A capacitive filter helps in reducing the ripples. A capacitive filter is shown below.

Figure 3.3: Circuit Diagram and the respective output waveforms of Capacitive Filter

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3.5 RF Transmitter STT-433MHz

Figure 3.4: RF Transmitter STT-433MHz

Figure 3.5: Transmitter circuit

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3.5.1. About the Transmitter:

The STT-433 is ideal for remote control applications where low cost and longer range is

required.

The transmitter operates from a1.5-12V supply, making it ideal for battery-powered applications.

The transmitter employs a SAW-stabilized oscillator, ensuring accurate frequency control for

best range performance.

The manufacturing-friendly SIP style package and low-cost make the STT-433 suitable for high

volume applications.

3.5.2. Features:

433.92 MHz Frequency

Low Cost

1.5-12V operation

3.5.3Pin Description:

GND: Transmitter ground-Connect to ground plane.

DATA: Digital data input. This input is CMOS compatible and should be driven with CMOS

level inputs.

VCC: Operating voltage for the transmitter. VCC bypassed with should be a .01uF ceramic

capacitor and filtered with a 4.7uF tantalum capacitor. Noise on the power supply will degrade

transmitter noise performance.

ANT: 50ohm antenna output. The antenna port impedance affects output power and harmonic

emissions.

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3.6 Basic Application circuit of HT640 Encoder

The encoder parallel bit data into serial bit data i.e, the antenna in the transmitter transmits the

signal to the receiver, which is of single bit through the medium of air.

Figure 3.6: HT640 Encoder

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Table 3.1: Pin description (HT640 Encoder)

3.7 RF Receiver STR-433MHz

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Figure 3.7: RF Receiver STR-433MHz

The data is received by the RF receiver fromthe antenna pin and this data is available on the data

pins. Two Data pins are provided in the receiver module. Thus, this data can be used for further

applications.

Figure 3.8: Pin diagram of RF Receiver STR-433MHz

3.7.1. Pin Description:

ANT- Antenna input.

GND-Receiver Ground. Connect to ground plane.

VCC-VCC pins areelectrically connected and provide operating voltage for the receiver. VCC

can be applied to either or both. VCC should be bypassed with a .1F ceramic capacitor. Noise

on the power supply will degrade receiver sensitivity.

DATA-Digital data output. This output is capable of driving one TTL or CMOS load. It is a

CMOS compatible output.

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3.8 Basic Application circuit of HT648L Decoder

Figure 3.9: HT648L Decoder

Similarly, as the transmitter requires an encoder, the receiver module requires a decoder. The

decoder used is HT648L from HOLTEK SEMICONDUCTOR INC

Table 3.2: Pin Description (HT648L Decoder)

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CHAPTER 4

MICROCONTROLLER

4.1. General Description

The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of

Flash programmable and erasable read only memory (PEROM). The device is manufactured using

Atmels high-density nonvolatile memory technology and is compatible with the industry-standard

MCS-51 instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed

in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU

with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides a

highly-flexible and cost-effective solution to many embedded control applications.

4.1.1. Features of ATMEL 89C51 Microcontroller

Compatible with MCS-51 Products

4K Bytes of In-System Reprogrammable Flash Memory

Endurance: 1,000 Write/Erase Cycles

Fully Static Operation: 0 Hz to 24 MHz

Three-level Program Memory Lock

128 x 8-bit Internal RAM

32 Programmable I/O Lines

Two 16-bit Timer/Counters

Six Interrupt Sources

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Programmable Serial Channel and Low-power Idle and Power-down Modes

4.1.2. Block Diagram ATMEL 89C51 Microcontroller

Figure 4.1: Block Diagram of AT89C51 microcontroller

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4.1.3. Pin Diagram ATMEL 89C51 Microcontroller

Figure 4.2: Pin Diagram of AT8951 microcontroller

4.1.4 Pin Description of ATMEL 89C51 Microcontroller

VCC: Pin 40 provides supply voltage to the chip. The voltage source is +5V.

GND:Pin 20 is the ground.

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XTAL1 and XTAL2: XTAL1 and XTAL2 are the input and output, respectively, of an inverting

amplifier that can be configured for use as an on-chip oscillator. Either a quartz crystal or

ceramic resonator may be used. To drive the device from an external clock source, XTAL2

should be left unconnected while XTAL1 is driven, as shown in the below figure. There are no

requirements on the duty cycle of the external clock signal, since the input to the internal

clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high

and low time specifications must be observed.

RESET: Pin9 is the reset pin. It is an input and is active high. Upon applying a high pulse to this

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

power-on reset.

EA (External access): Pin 31 is EA. It is an active low signal. It is an input pin and must be

connected to either Vcc or GND but it cannot be left unconnected.

PSEN (Program store enable): This is an output pin.

ALE (Address latch enable): This is an output pin and is active high.

Ports 0, 1, 2 and 3:The four ports P0, P1, P2 and P3 each use 8 pins, making them 8-bit ports.

All the ports upon RESET are configured as input, since P0-P3 have value FFH on them.

Table 3: Alternate Functions of port 3

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The assembly language program is written and this program has to be dumped into the microcontroller

for the hardware kit to function according to the software. The program dumped in the microcontroller is

stored in the Flash memory in the microcontroller.

CHAPTER 5

H-BRIDGE

An H-bridge is an electronic circuit which enables DC electric motors to be run forwards or

backwards. These circuits are often used in robotics. H-bridges are available as integrated circuits, or

can be built from discrete components.

Figure 5.1: Graphical representation of H-Bridge

An H-bridge is built with four switches (solid-state or mechanical). When the switches S1 and S4

(according to the first figure) are closed (and S2 and S3 are open) a positive voltage will be appliedacross the motor. By opening S1 and S4 switches and closing S2 and S3 switches, this voltage is

reversed, allowing reverse operation of the motor

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The H-Bridge arrangement is generally used to reverse the polarity of the motor, but can also be

used to 'brake' the motor, where the motor comes to a sudden stop, as the motors terminals are shorted,

or to let the motor 'free run' to a stop, as the motor is effectively disconnected from the circuit.

The following table summarizes operation

Table 4: Operation of H-Bridge

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CHAPTER 6

METAL DETECTOR

The simplest form of a metal detector consists of an oscillator producing an alternating current that

passes through a coil producing an alternating magnetic field. If a piece of electrically conductive metal

is close to the coil, eddy currents will be induced in the metal, and this produces an alternating magnetic

field of its own. If another coil is used to measure the magnetic field (acting as a magnetometer), the

change in the magnetic field due to the metallic object can be detected.

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Figure 6.1: Metal Detecting circuit

CHAPTER 7

WIRELESS CAMERA WITH VOICE TRANSMISSION

The portable small-sized camera has the ball-point pen appearance, photographing a particular

location in secret is possible without exposure to others. The camera circuit part is connected to a

wireless transmission device for outputting a signal by a cable. A wireless receiving device at a remote

location from the wireless transmission device receives a signal of the wireless transmission device for

outputting or recording.

7.1. RF Transmitter (Remote) Block Diagram

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SW1

SW2

SW3

SW4

RF

Encoder

HT640 RF

Transmitter

STT - 433

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Figure 7.1: Block Diagram of RF Transmitter (Remote)

7.2. RF Receiver (Remote) Block Diagram

xxx

RF Receiver

RF

Decoder

89C51

MCU

H-

Bridge

H-Bridge

Geared

Motor - I

GearedMotor - II

Power On

RESET

MetalDetector

Wireless Camera with voice

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Figure 7.2: Block Diagram of RF Receiver (Remote)

CHAPTER 8

WORKING OF THE PROJECT

This project (Remote Controlled Metal Detecting Robot with Image Transmission) consists of

two sections-Transmitter section (Remote) and Receiver section (Robot).

8.1. RF Transmitter (Remote)

In the transmitter section (remote), we have the following components:

Four switches

RF encoder (HT640L)

RF transmitter (STT-433MHz)

There are four switches for the movement of the robot in various directions like forward,

backward, left and right. These four switches are connected to the RF encoder . The RF encoder is then

connected to RF transmitter, which is thereby connected to the antenna for the transmission of the radio

waves.

Depending on the switch that is been pressed (left, right, forward, and backward), the digital data

from the switches is transferred to the RF encoder, which encodes this digital data into RF signals and

transmits to the RF transmitter. This transmitter transmits the RF waves to the receiver (robot) through

the antenna.

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8.2. RF Receiver (Robot)

The receiver section consists of the following components:

RF receiver (STR-433MHz)

RF decoder (HT648L)

Microcontroller (AT89C51)

H-Bridge

Geared motors of 60RPM

Metal detecting circuit

Wireless camera

In this receiver section, the RF receiver is connected to the RF decoder. This decoder is

connected to the microcontroller, which is, in turn, connected to the H-Bridge. This H-Bridge is

connected to the geared motors of the robot. Metal detecting circuit is also other separate sub-section on

the receiver part. The wireless camera is placed separately on the receiver section to view the

surroundings.

When the radio waves are transmitted from the transmitter (remote) to the receiver (robot), these

waves are received by the RF receiver through the receiver antenna. From the RF receiver the signals are

sent to RF decoder, which decodes these signals into digital data. This digital data is sent to the

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microcontroller, which, depending on the code written in it, enables either the upper H-Bridge or lower

H-Bridge. This H-Bridge correspondingly activates the specified geared motors (Geared Motors-I or

Geared motors-II). Power set reset button is used for activating the receiver section. Metal detecting

circuit is other sub-section on the receiver part.

As the robot moves in any specified direction and if a metal is been placed on the path of the

robot., the inducting coil present at the lower side of the receiver section, which acts as a metal

detecting coil, will detect the metal and activates the buzzer sound on the receiver section. The metal

detection processes goes on by induction of eddy currents in the metal due to the variation in the

magnetic fields of the two components-coils and metal.

The wireless camera is placed to view the images surrounding the robot to locate the position of

the metal being detected. The images can be viewed on a television at the user location. When the robot

moves the camera also moves as per the adjustment of the camera on the receiver section. This provides

the view of the location of the robot. Whenever the metal is detected, which we can be aware by the

sound of the buzzer on the receiver section, we view the location of the mine with the help of the

surrounding view provided by the camera through a television placed at our location. This feature makes

the project more specific in applications like for metal detecting and other applications

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CHAPTER 9

PROGRAMMING THE FLASH (CODE)

The AT89C51 is normally shipped with the on-chip Flash memory array in the erased state (that

is, contents = FFH) and ready to be programmed. The programming interface accepts either a high-

voltage (12-volt) or a low-voltage (VCC) program enable signal. The low-voltage programming mode

provides a convenient way to program the AT89C51 inside the users system, while the high-voltage

programming mode is compatible with conventional third party Flash or EPROM programmers. The

AT89C51 is shipped with either the high-voltage or low-voltage programming mode enabled.

9.1. Programming Algorithm:

Before programming the AT89C51, the address, data and control signals should be set up

according to the Flash programming mode table. To program the AT89C51, the following steps should

be considered:

1. Input the desired memory location on the address lines.

2. Input the appropriate data byte on the data lines.

3. Activate the correct combination of control signals.

4. Raise EA/VPP to 12V for the high-voltage programming mode.

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5. Pulse ALE/PROG once to program a byte in the Flash array or the lock bits. The byte-write cycle

is self-timed and typically takes no more than 1.5 ms.

6. Repeat steps 1 through 5, changing the address and data for the entire array or until the end of the

object file is reached.

9.2. Project Code:

#include

#definerfdataP1

void stop(void);

void forward(void);

void left(void);

void right(void);

void backward(void);

void main()

{

rfdata=0xff;

P0=0;

P3=0;

while(1)

{

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if(rfdata==0x0f)

{

while(rfdata==0x0f)

{

stop();

}

}

if(rfdata==0x0e)

{

forward();

}

}

void forward(void)

{

P0=0xCA;

P3=0:

}

The present project is implemented on Keil Uvision. In order to program the device, proload tool

has been used to burn the program onto the microcontroller.

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CHAPTER 10

RESULTS

Figure 10.1: RF Receiver Section

(Robot)

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Figure 10.2: RF Transmitter Section (Remote)

ADVANTAGES AND DISADVANTAGES

Advantages:

1. No line of sight is needed.

2. Not blocked by common materials: It can penetrate most solids and pass through walls.

3. Longer range.

4. It is not sensitive to the light;.

5. It is not much sensitive to the environmental changes and weather conditions.

Disadvantages:

1. Interference: communication devices using similar frequencies - wireless phones, scanners, wrist

radios and personal locators can interfere with transmission

2. Lack of security: easier to "eavesdrop" on transmissions since signals are spread out in space

rather than confined to a wire

3. Higher cost than infrared

4. Federal Communications Commission(FCC) licenses required for some products

5. Lower speed: data rate transmission is lower than wired and infrared transmission

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LIMITATIONS

Limitations in this project are

1. While working on this project, we had a difficulty of adjusting the RF frequency for our project.

2. We had to tune the frequency in the RF range in such a way that the frequency used in our

project should not be used anywhere in the closer vicinity of the project.

3. Therefore we had to tune the frequency range between 340MHz to 415MHz.

4. Finally we had rectified the problem by setting the frequency at 384.9MHz.

5. High cost and high tech features are additional constraints in using robots for

demining.

6. The knowledge required to operate a machine may not match the skill level of the demines,

many of whom are drawn from the local public.

7. The main limitations of this robot are:

a. Not suitable for difficult terrain

b. Hard to navigate

c. Blast-resistant wheels are unsuited to very soft ground, and

d. The inability of the robot with its particular wheel configuration and available

power to have enough torque to get out of a hole after a mine blast.

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8. In addition, cost of maintenance, spare parts and its availability are critical parameters too. While

current technology may be slightly effective, it is far too limited to fully address the huge mine.

9. Here two main steps can be distinguished: first the presence of an object

must be detected, and secondly this object has to be identified as being a mine or other.

Critical to demining is the ability to distinguish fragments or stones from the target material.

APPLICATIONS

1. Mines detection

This remote controlled metal detecting robot with image transmission can be used for

detection of mines in remote and others places also with an image view through the television, to

know the location of the mine. Since whenever this robot passes through a mine, it detects the

mine and produces a buzzer sound and thereby the location of the mine can be traced out by the

television used.

2. Surveillance appliances.

With the help of microcontroller, remote and other intelligent control technologies

embedded in the project offer the end user to easily access greater control of their products. The

use of a camera helps to view the location under control. the projects various surveillance

appliances include the monitoring of the robot and thereby the view of the camera so as to

observe the location being detected.

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CONCLUSION

This project presents a metal detecting robot using RF communication with wireless audio and

video transmission and it is designed and implemented with Atmel 89C51 MCU in embedded system

domain.

The robot is moved in particular direction using switches and the images are captured along with

the audio and images are watched on the television .Experimental work has been carried out carefully.

The result shows that higher efficiency is indeed achieved using the embedded system. The proposed

method is verified to be highly beneficial for the security purpose and industrial purpose.

The mine sensor worked at a constant speed without any problem despite its extension, meeting

the specification required for the mine detection sensor. It contributed to the improvement of detection

rate, while enhancing the operability as evidenced by completion of all the detection work as scheduled.

The tests demonstrated that the robot would not pose any performance problem for installation of the

mine detection sensor. On the other hand, however, the tests also clearly indicated areas where

improvement, modification, specification change and additional features to the robot are required to

serve better for the intended purpose. Valuable data and hints were obtained in connection with such

issues as control method with the mine detection robot tilted, merits and drawbacks of mounting the

sensor, cost, handling the cable between the robot and support vehicle, maintainability, serviceability

and easiness of adjustments. These issues became identified as a result of our engineers conducting both

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the domestic tests and the overseas tests by themselves, and in this respect the findings were all the more

practical.

REFERENCES

Text Books:

[1] Raj Kamal, Embedded Systems, Pearson Education Publications, 2007.

[2] Mazzidi, 8051 Microcontroller and Embedded Systems, Prentice Hall

Publications, 2nd Edition, 2005.

[3] Edwin S.Grosvenor and Morgan Wesson,Alexander Graham Bell: The Life and

Times of the Man Who Invented the Telephone , New York, Abrams, 1997.

Magazines:

[1] Electronics for you

[2] Electrikindia

Web portal:

[1] www.howstuffworks.com.

[2] http://www.atmel.com/dyn/resources/prod_documents/doc0265.pdf.

[3] www.intechopen.com/download/pdf/pdfs_id/68.pdf.

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