UG Major Project - Wireless Bomb Detection Robot

A Project Report On

“WIRELESS B BOMB D DETECTION R ROBOT” Submitted in partial fulfillment of the requirements for the award of the degree of

BACHELOR OF TECHNOLOGY IN ELECTRONICS AND COMMUNICATION ENGINEERING BY

ADITYA BADAMI

(097F1A0402)

TAMMADI BABU RAO

(097F1A0405)

G. SRI SAI RATNA

(097F1A0425)

Under the guidance of

Mrs. S. NIHARIKA Asst. Professor Department of ECE

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES

Approved by AICTE, New Delhi & Affiliated to JNTU, Hyderabad. Nadergul (V), Saroor Nagar (M), Ranga Reddy (Dist) A. P. – 501510

Date: __________________

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING

CERTIFICATE

This is to certify that Project entitled “WIRELESS BOMB DETECTION ROBOT” is a bonafide work carried out by ADITYA BADAMI (097F1A0402), TAMMADI BABU RAO (097F1A0405), G. SRI SAI RATNA (097F1A0425) in partial fulfillment

for the award of Bachelor of Technology in Department of ECE, “VISHWA BHARATHI INSTITUTE OF TECHNOLOGY AND SCIENCES”, Hyderabad

during the year 2009-2013 under my supervision and guidance. The result embodied in this Project Work has not been submitted s ubmitted to any other University or Institute for the award of any Degree

INTERNAL GUIDE

HEAD OF THE DEPARTMENT

Mrs. S. NIHARIKA (Asst. Professor)

Mr.C.ASHOK VISHNU

PRINCIPAL

EXTERNAL EXAMINER

i

DECLARATION

We the undersigned, declare that the project title entitled “WIRELESS BOMB DETECTION ROBOT” carried out at “WINEYARD TECHNOLOGIES” is

original and is being submitted to the Department of ECE “VISHWA BHARATHI INSTITUTE OF TECHNOLOGY AND SCIENCES”, Hyderabad towards partial

fulfillment for the award of Bachelor of Technology. We, declare that, the result embodied in the Project work has not been submitted to any other University or Institute for the award of any Degree.

Date:

ADITYA BADAMI

Place: Hyderabad

TAMMADI BABU RAO (097F1A0405) G. SRI SAI RATNA

iii

(097F1A0402) (097F1A0402)

(097F1A0425)

ACKNOWLEDGEMENT

The completion of this project work gives us an opportunity to convey our gratitude to all those who have helped us to reach a stage where we have the confidence to launch our career in the competitive world in the field of ELECTRONICS AND COMMUNICATION ENGINEERING.

We express our sincere thanks to “ Dr. D.MAHESHWAR REDDY” Principal, “VISHWA BHARATHI INSTITUTE OF TECHNOLOGY AND SCIENCES”

for providing all necessary facilities in completing our project report.

We express our sense of gratitude to Mr. C.ASHOK VISHNU Head of Department of ECE, who encouraged us to select the project and completion of this project with providing necessary facilities Our honest thankfulness to Mrs. S. NIHARIKA, (Internal Guide) for her kind help and for giving us the necessary guidance and valuable suggestions in completing this project work and in preparing this report. We take the opportunity to express gratitude to the Management, Teaching and Non teaching Staff of “VISHWA BHARATHI INSTITUTE OF TECHNOLOGY AND c o-operation during the period of my Study. SCIENCES” for their kind co-operation Finally, we would like to thank our parents & friends for their continuous encouragement and support during the entire course of this project work.

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ABSTRACT

The aim of our project is to design a wireless robot for bomb surveillance and detection with a metal detector and to diffuse it by using a mobile jammer. This is an interesting robot that can be controlled by hand gestures and by an RF remote. This can be moved in forward and reverse direction using geared motors of 60RPM. Also this robot can take sharp turnings towards left and right directions. This project uses Arduino MCU as its controller. A high sensitive induction type metal detector is designed using colpitts oscillator principle and fixed to this robot. Also a mobile phone signal isolator is interfaced to the kit. When the robot is moving on a surface, the system produces a beep sound when Bomb is detected. Simultaneously a signal is fed to the jammer section to switch on the jammer. This jammer diffuses the bomb by jamming the mobile signal of GSM or CDMA or 3G networks. The RF modules used here are STT-433 MHz Transmitter, STR-433 MHz Receiver, HT12E RF Encoder and HT12D RF Decoder. The 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.

v

LIST OF CONTENTS TITLE

PAGE NO i ii iii iv v vi viii ix

Certificate from the Department Certificate from the Organization Declaration Acknowledgement Abstract Table of Contents List of Figures List of Tables

CHAPTER-1:

INTRODUCTION

1

CHAPTER-2:

BLOCK DIAGRAM

4

2.1 2.2 2.3

Transmitter block Receiver block Hardware implementation

4 5 6

HARDWARE DETAILS

8

Power supply Accelerometer Encoder HT12E RF Technology Decoder HT12D Mobile Jammer Metal Detector Buzzer Liquid Crystal Display DC Motor H-Bridge Microcontroller

8 9 11 12 13 14 16 16 17 18 21 24

WIRELESS COMMUNICATION

26

Introduction Properties of RF Brief description of RF Different RF Ranges and Applications RF Transmitter STT-433MHZ RF Receiver STR-433MHZ RF Advantages

26 27 27 28 29 31 33

CHAPTER-3: 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12

CHAPTER-4: 4.1 4.2 4.3 4.4 4.5 4.6 4.7

vi

4.8 4.7 4.8

RF Disadvantages Interfacing of RF Transmitter with AT89S52 Interfacing of RF Receiver with ARDUINO

33 34 34

MEMS TECHNOLOGY

35

MEMS Introduction Accelerometer Interfacing of MEMS sensor with Microcontroller

35 38 41

MICROCONTROLLER

42

Introduction Features PIN Description of AT89S52 ARDUINO ATmega328 Microcontroller

42 42 43 46 49

SOFTWARE DETAILS

52

KEIL Software PROLOAD ARDUINO Software tools

52 54 55

SCHEMATIC REPRESENTATION

60

Schematic representation of Transmitter Schematic representation of Receiver

60 61

APPLICATIONS AND ADVANTAGES

62

Applications Advantages

62 62

CHAPTER-10:

RESULT

63

CHAPTER-11: CHAPTER-11 :

CONCLUSION AND FUTURE SCOPE

66

CHAPTER-5: 5.1 5.2 5.3

CHAPTER-6: 6.1 6.2 6.3 6.4 6.5

CHAPTER-7: 7.1 7.2 7.3

CHAPTER-8: 8.1 8.2

CHAPTER-9: 9.1 9.2

67

REFERENCES APPENDIX

vii

LIST OF FIGURES FIG NO.

DESCRIPTION

PAGE NO.

FIG 3.1 FIG 3.2 FIG 3.3 FIG 3.4 FIG 3.5 FIG 3.6 FIG 3.7 FIG 3.8 FIG 3.9 FIG 3.10 FIG 3.11 FIG 3.12 FIG 3.13 FIG 3.14 FIG 3.15 FIG 3.16 FIG 3.17 FIG 4.1 FIG 4.2 FIG 4.3 FIG 4.4 FIG 4.5 FIG 5.1 FIG 5.2 FIG 5.3 FIG 5.4 FIG 5.5 FIG 6.1 FIG 6.2 FIG 6.3 FIG 6.4

Components of RPS Accelerometer G-Whiz Encoder PIN diagram RF Transmitter and Decoder PIN Diagram Mobile Jammer Jammer Signal Buzzer LCD display Two Pole DC Motor Rotation DC Motor Three Pole DC Motor DC Motor Circuit of H-Bridge Block Diagram of H-Bridge PIN Connection RF Transmitter Applications RF Receiver PIN Diagram of RF Receiver Digital Data PIN Components of MEMS Accelerometer The Piezo electric Accelerometer G-Whiz Surface Micro Machined Accelerometer AT89S52 PIN Diagram Arduino Board Arduino PIN diagram AT mega PIN diagram

viii

8 9 10 11 12 13 14 15 17 17 18 19 20 20 21 23 24 29 30 31 31 32 35 38 38 39 40 43 46 47 50

LIST OF TABLES TABLE NO.

DESCRIPTION

PG NO.

Table 3.1 Table 3.2 Table 3.3 Table 3.4 Table 4.1 Table 6.1 Table 6.2

Encoder PIN Description Decoder PIN Description H-Bridge Absolute Maximum Ratings Different RF Ranges and Applications Port 1 Port 3

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12 13 22 23 28 44 45

WIRELESS BOMB DETECTION ROBOT

ECE

CHAPTER-1 INTRODUCTION 1.1 INTRODUCTION TO PROJECT A Robot is a mechatronics device which also includes resourcefulness or autonomy. A device with autonomy does its thing "on its own" without a human directly guiding it moment-by-moment. Some authors would contend that all mechatronic devices are robots, and that this book's restriction re striction on robot entails only specialized s oftware. Robotics can be described as the current pinnacle of technical development. Robotics is a confluence science using the continuing advancements of mechanical engineering, material science, sensor fabrication, manufacturing techniques, and advanced algorithms. The study and practice of robotics will expose a dabbler or professional to hundreds of different avenues of study. For some, the romanticism of robotics brings forth an almost magical curiosity of the world leading to creation of amazing machines. A journey of a lifetime l ifetime awaits in robotics. Robotics can be defined as the science or study of the technology primarily associated with the design, fabrication, theory, and application of robots. While other fields contribute the mathematics, the techniques, and the components, robotics creates the magical end product. The practical applications of robots drive development of robotics and drive advancements in other sciences in turn. Crafters and researchers in robotics study more than tha n just robotics. In this project we use a robot and it is controlled by hand gestures and these hand movements are recognized by the hand gesture technology and based on the movement of the hand the robot is moved in the respective direction i.e. either in forward, backward, left or right. The benefits of such robots to these operations include reduced personnel requirements, reduced fatigue, and access to otherwise unreachable areas. Robotic search is useful since robots may be deployed in dangerous environments without putting human responders at risk . This project is a prototype which is widely used for military applications.

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1.2 INTRODUCTION TO EMBEDDED SYSTEM: An Embedded System is a combination of computer hardware and software, and perhaps additional mechanical or other parts, designed to perform a specific function. A good example is the microwave oven. Almost every household has one, and tens of millions of them are used every day, but very few people realize that a processor and software are involved in the preparation of t heir lunch or dinner. This is in direct contrast to the personal computer in the family room. It too is comprised of computer hardware and software and mechanical components (disk drives, for example). However, a personal computer is not designed to perform a specific function rather; it is able to do many different things. Many people use the term general-purpose computer to make this distinction clear. As shipped, a generalpurpose computer is a blank slate; the manufacturer does not know what the customer will do wish it. One customer may use it for a network file server another may use it exclusively for playing games, and a third may use it to write the next great American novel. Frequently, an embedded system is a component within some larger system. For example, modern cars and trucks contain many embedded systems. One embedded system controls the anti-lock brakes, other monitors and controls the vehicle's emissions, and a third displays information on the dashboard. In some cases, these embedded systems are connected by some sort of a communication network, but that is certainly not a requirement. At the possible risk of confusing you, it is important to point out that a general-purpose computer is itself made up of numerous embedded systems. For example, my computer consists of a keyboard, mouse, video card, modem, hard drive, floppy drive, and sound card-each of which is an embedded system. Each of these devices contains a processor and software and is designed to perform a specific function. For example, the modem is designed to send and receive digital data over analog telephone line. That's it and all of the other devices can be summarized in a single sentence as well.


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If an embedded system is designed well, the existence of the processor and software could be completely unnoticed by the user of the device. Such is the case for a microwave oven, VCR, or alarm clock. In some cases, it would even be possible to build an equivalent device that does not contain the processor and software. This could be done by replacing the combination with a custom integrated circuit that performs the same functions in hardware. However, a lot of flexibility is lost when a design is hard-cooled in this way. It is much easier, and cheaper, to change a few lines of software than to redesign a piece of custom hardware.

1.3 MEMS TECHNOLOGY: Micro-Electro-Mechanical Systems, or MEMS, is a technology that in its most general form can be defined as miniaturized mechanical and electro-mechanical elements (i.e., devices and structures) that are made using the techniques of micro fabrication. The critical physical dimensions of MEMS devices can vary from well below one micron on the lower end of the dimensional spectrum, all the way to several millimeters. Likewise, the types of MEMS devices can vary from relatively simple structures having no moving elements, to extremely complex electromechanical systems with multiple moving elements under the control of integrated microelectronics. The one main criterion of MEMS is that there are at least some elements having some sort of mechanical functionality whether or not these elements can move. The term used to define MEMS varies in different parts of the world. In the United States they are predominantly called MEMS, while in some other parts of the world they are called “Microsystems Technology” or “micro machined devices”. Micro sensors and micro actuators are appropriately categorized as “transducers”, which are defined as devices that convert energy from one form to another. In the case of micro sensors, the device typically converts a measured mechanical signal into an electrical signal. VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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CHAPTER-2 BLOCK DIAGRAM 2.1 TRANSMITTER BLOCK

LCD Display

Hand gesture recognizerACCELER OMETER

Step down

T/F

RF AT89S52

Bridge Rectifier

Filter Circuit

ENCODER

Transmitter

HT12E

STT - 433

Regulator


Power supply to all

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2.2 RECEIVER BLOCK

Power su l

Geared Motor -

RF Receiver

RF Decoder

HBridge Geared Motor 2

Arduino Reset Buzzer

Metal Detector

Lead acid battery

Regulator

Mobile Isolator

Power supply to all sections


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2.3 HARDWARE IMPLEMENTATION: 2.3.1 INTRODUCTION: In this project we use a robot and it is controlled by hand gestures and these hand movements are recognized by the hand gesture technology and based on the movement of the hand the robot is moved in the respective direction i.e. either in forward, backward, left or right. The benefits of such robots to these operations include reduced personnel requirements, reduced fatigue, and access to otherwise unreachable areas. Robotic search is useful since robots may be deployed in dangerous environments without putting human responders at risk . This project is a prototype which is widely used for military applications

2.3.2 COMPONENTS USED: 

Accelerometer



AT89S52 Micro Controller



Power Supply Unit



LCD Display



Buzzer



RF Transmitter



RF Receiver



Arduino Micro Controller



Motors



Metal Detector



Mobile Jammer

2.3.3 WORKING PROCEDURE: The block diagram consists of data transmitter and data receiver blocks.

TRANSMITTER BLOCK: As the overall system contains two microcontroller units, the function of microcontrollers differ to each other, two different software programs are prepared to function as data transmitter and data receiver. VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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The data transmitting unit consists of the following devices: 

Accelerometer



AT89S52 micro controller



Power Supply Unit



RF Transmitter



LCD Display In our project, here we are using MEMS sensor i.e. accelerometer is given to

the port (P2.6- P2.7 ) of micro controller AT89S52. The hand gesture given to accelerometer, this data is sent from AT89S52 to RF transmitter from (P2.0- P2.3 ) Simultaneously the direction of hand gesture made by accelerometer is displayed on LCD which is interfaced with AT89S52 to the port ( P1.0-P1.6).

RECEIVER BLOCK: Similarly, the data receiving unit consists of the following devices: 

RF Receiver



Arduino Microcontroller



Motors



Metal Detector



Mobile Jammer



Buzzer The data which is transmitted from RF transmitter is received by RF receiver.

This information is sent to Arduino (ATMEGA 328).From Arduino the data is sent to H-Bridge through Port ( PC0-PC3) and the motor moves according to the hand gesture made. While the robot is moving, we have added a metal detector externally which works on a separate battery. This metal detector is connected to buzzer as well as mobile jammer. If metal detector detects the bomb, the buzzer makes the sound and automatically mobile jammer is activated.


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CHAPTER-3 HARDWARE DETAILS 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.

Figure 3.1 Components of a regulated power supply

3.1.1 TRANSFORMER Usually, DC voltages are required to operate various electronic equipment and these voltages are 5V, 9V or 12V. But these voltages cannot be obtained directly. Thus the a.c input available at the mains supply i.e., 230V is to be brought down to the required voltage level. This is done by a transformer. Thus, a step down transformer is employed to decrease the voltage to a required level. VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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3.1.2 RECTIFIER The output from the transformer is fed to the rectifier. It converts A.C. into pulsating D.C. The rectifier may be a half wave or a full wave rectifier. In this project, a bridge rectifier is used because of its merits like good stability and full wave rectification.

3.1.3 FILTER Capacitive filter is used in this project. It removes the ripples from the output of rectifier and smoothens the D.C. Output received from this filter is constant until the mains voltage and load is maintained constant. However, if either of the two is i s varied, D.C. voltage received at this point changes. Therefore a regulator is applied at the output stage.

3.1.4 VOLTAGE REGULATOR As the name itself implies, it regulates the input applied to it. A voltage regulator is an electrical regulator designed to automatically maintain a c onstant voltage level. In this project, power supply of 5V and 12V are required. In order to obtain these voltage levels, 7805 and 7812 voltage regulators are to be used. The first number 78 represents positive supply and the numbers 05, 12 represent the required output voltage levels.

3.2 ACCELEROMETER An accelerometer is an apparatus, either mechanical or electromechanical, for measuring acceleration or deceleration - that is, the rate of increase or decrease in the velocity of a moving object. Accelerometers are used to measure the efficiency of the braking systems on road and rail vehicles; those used in aircraft and spacecraft can determine accelerations in several directions simultaneously. There are also accelerometers

for

detecting

vibrations

in

machinery.

Figure 3.2 Accelerometer


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3.2.1 G-WHIZ The ADXL202 two-axis ý2- g accelerometer from Analog Devices is a good example of a micro machine that’s making waves in the commercial market. More sensitive than earlier airbag designs, it’s well suited for novel applications like two-axis tilt sensing and inertial navigation. For instance, Microsoft is using the ’202 in their new Freestyle Pro game controller, which senses body motion. The basic principle of micro machined accelerometers is simple enough. A tethered or "sprung" mass is forced into motion by an applied acceleration. The distance that the mass moves, and thus the acceleration, is determined by differential capacitance, as shown in figure.

Figure 3.3—G-Whiz

The principle may be simple, but the implementation is incredible, given the intricacy of crafting it in silicon. Consider that the smallest detectable capacitance change, 20 zF (yes, that’s "z" as in 10–21 F), corresponds to a 2-pm deflection! But while it’s capable of resolving mere m g’s (thousandths of a g), the device can take a 500–1000-g hit and keep on ticking. The use of a standard IC process means the same die can integrate signalconditioning and digitizing circuits, dispensing with the design hassles of dealing with low-level analog signals. That makes the ADXL202 real easy to use. Just add power (3–5.25 V, a mere 1 mA at that) and have at it with your favorite MCU or PLD.


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3.3 ENCODER HT12E: The encoder used here is HT12E from HOLTEK SEMICONDUCTORS INC. The HT 12E Encoder ICs are series of CMOS LSIs for Remote Control system applications. They are capable of Encoding 12 bit of information which consists of N address bits and 12-N data bits. Each address/data input is externally trinary programmable if bonded out.

3.3.1 PIN DIAGRAM:

Figure 3.4 Encoder pin diagram

3.3.2 PIN DESCRIPTION:


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Table 3.1 Encoder Pin Description

3.4 RF TECHNOLOGY: Radio frequency (RF) is a frequency or rate of oscillation within the range of about 3

Hz 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 that most mechanical systems can respond to, RF usually refers to oscillations in electrical circuits or electromagnetic radiation. Radio frequency is a frequency or rate of oscillation within the range of about 3 Hz 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 that 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.

Figure 3.5 RF Transmitter and RF Receiver


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3.5 DECODER HT12D: The decoder used is HT12D from HOLTEK SEMICONDUCTOR INC.

Figure 3.6 Decoder Pin diagram

Table 3.2 Decoder Pin Description


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FEATURES •

Operating voltage: 2.4V~12V.

•

Low power and high noise immunity CMOS technology.

•

Low standby current.

•

Capable of decoding 18 bits of information.

•

Pairs with HOLTEK’s 318 series of encoders.

•

8~18 address pins.

•

0~8 data pins.

3.6 MOBILE JAMMER •

A portable cell phone jammer featured by universal and handheld design, could blocking worldwide cell phone networks within 0.5-10 meters, including GSM900MHz, GSM1800MHz, GSM850MHz/CDMA800MHz and also 3G networks (UMTS / W-CDMA).

Figure 3.7 Mobile Jammer •

A mobile phone jammer is an instrument used to prevent cellular phones from receiving signals from or transmitting signals to base stations. When used, the jammer effectively disables cellular phones. These devices can be used in practically any location, but are found primarily in places where a phone call would be particularly disruptive because s ilence is expected.


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OPERATION •

As with other radio jamming, cell phone jammers block cell phone use by sending out radio waves along the same frequencies that cellular phones use. This causes enough interference with the communication between cell phones and towers to render the phones unusable. On most retail phones, the network would simply appear out of range. Most cell phones use different bands to send and receive communications from towers (called full duplexing). Jammers can work by either disrupting phone to tower frequencies or tower to phone frequencies. Smaller handheld models block all bands from 800MHz to 1900MHz within a 30-foot range (9 meters). Small devices tend to use the former method, while larger more expensive models may interfere directly with the tower. The radius of cell phone jammers can range from a dozen feet for pocket models to kilometers for more dedicated units. The TRJ-89 jammer can block cellular communications for a 5-mile (8 km) radius.

•

Actually it needs less energy to disrupt signal from tower to mobile phone, than the signal from mobile phone to the tower (also called base station), because base station is located at larger distance from the jammer than the mobile phone and that is why the signal from the tower is not so strong.

Figure 3.8 Jammer Signal •

Older jammers sometimes were limited to working on phones using only analog or older digital mobile phone standards. Newer models such as the double and triple band jammers can block all widely used systems (CDMA,


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iDEN, GSM, et al.) and are even very effective against newer phones which hop to different frequencies and systems when interfered with. As the dominant network technology and frequencies used for mobile phones vary worldwide, some work only in specific regions such as Europe or North America. •

The jammer's effect can vary widely based on factors such as proximity to towers, indoor and outdoor settings, presence of buildings and landscape, even temperature and humidity play a role.

•

There are concerns that crudely designed jammers may disrupt the functioning of medical devices such as pacemakers. However, like cell phones, most of the devices in common use operate at low enough power output (<1W) to avoid causing any problems.

3.7 METAL DETECTOR: •

Metal detectors use electromagnetic induction to detect metal. Metal detector can help you to find the metals buried deep in the ground. Uses include demining (the detection of land mines), the detection of weapons such as knives and guns, especially at airports, geophysical prospecting, archaeology and treasure hunting. Metal detectors are also used to detect foreign f oreign bodies in food, and in the construction industry to detect steel reinforcing bars in concrete and pipes and wires buried in walls and floors.

•

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.

3.8 BUZZER: An electric coil is wound on a plastic bobbin, the latter having a central sleeve within which a magnetic core is slide ably positioned. One end of the sleeve is closed and VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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projects beyond the coil. An inverted cup-shaped housing surrounds the coil and bobbin and has a central opening through which the closed end of the sleeve projects. The core projects into the closed end of the sleeve beyond the margin of the opening in the housing to augment the magnetic coupling between the housing and the core. The open end of the housing is attached to a support bracket of magnetic material, there being a spring between the bracket and bobbin normally urging the core toward the closed end of the sleeve.

Figure 3.9 Buzzer

3.9 LIQUID CRYSTAL DISPLAY: LCD stands for Liquid Crystal Display. LCD is finding wide spread use replacing LEDs (seven segment LEDs or other multi segment LEDs). These components are “specialized” for being used with the microcontrollers, which means that they cannot be activated by standard IC circuits. They are used for writing different messages on a miniature m iniature LCD.

Figure 3.10 LCD Display

A model described here is for its low price and great possibilities most frequently used in practice. It is based on the HD44780 microcontroller ( Hitachi) and can display messages in two lines with 16 characters each.


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It displays all the alphabets, Greek letters, punctuation marks, mathematical symbols etc. In addition, it is possible to display symbols that user makes up on its own. Automatic shifting message on display (shift left and right), appearance of the pointer, backlight etc. are considered as useful c haracteristics.

3.10 DC MOTOR: A DC motor is an electric motor that runs on direct current (dc) electricity.

3.10.1 DC MOTOR CONNECTIONS Figure shows schematically the different methods of connecting the field and armature circuits in a DC Motor. The circular symbol represents represents the armature armature circuit, and the squares at the side of the circle circle represent the brush commutator system. The direction of the arrows arrows indicates the direction of the magnetic fields.

3.10.2 PRINCIPLES OF OPERATION: In any electric motor, operation is based on simple electromagnetism. A currentcarrying conductor generates a magnetic field; when this is then placed in an external magnetic field, it will experience a force proportional to the current in the conductor, and to the strength of the external magnetic field. The internal configuration of a DC motor is designed to harness the magnetic interaction between a current-carrying conductor and an external magnetic field to generate rotational motion. Let's start by looking at a simple 2-pole DC electric motor (here red represents a magnet or winding with a "North" polarization, while green represents a magnet or winding with a "South" polarization).

Figure 3.11 Two Pole DC Motor

Every DC motor has six basic parts -- axle, rotor (a.k.a., armature), stator, commutator, field magnet(s), and brushes. In most common DC motors (and all that VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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Beamers will see), the external magnetic field is produced by high-strength permanent permanent magnets. The stator is the stationary part of the motor -- this includes the motor casing, as well as a s two or more permanent magnet pole pieces. The rotor (together with the axle and attached commutator) rotates with respect to the stator. The rotor consists of windings (generally on a core), the windings being electrically connected to the commutator. The above diagram shows a common motor layout -- with the rotor inside the stator (field) magnets. The geometry of the brushes, commutator contacts, and rotor windings are such that when power is applied, the polarities of the energized winding and the stator magnet(s) are misaligned, and the rotor will rotate until it is almost aligned with the stator's field magnets. As the rotor reaches alignment, the brushes move to the next commutator contacts, and energize the next winding. Given our example two-pole motor, the rotation reverses the direction di rection of current through the rotor winding, leading to a "flip" of the t he rotor's magnetic field, driving it to continue rotating. In real life, though, DC motors will always have more than two poles (three is a very common number). In particular, this avoids "dead spots" in the commutator. You can imagine how with our example two-pole motor, if the rotor is exactly at the middle of its rotation (perfectly aligned with the field magnets), it will get "stuck" there. Meanwhile, with a two-pole motor, there is a moment where the commutator shorts out the power supply (i.e., both brushes touch both commutator contacts simultaneously). This would be bad for the power supply, waste energy, and damage motor components as well. Yet another disadvantage of such a simple motor is that it would exhibit a high amount of torque "ripple" (the a mount of torque it could produce is cyclic with the position of the rotor).

Figure 3.12 Rotation DC Motor


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So since most small DC motors are of a three-pole design, let's tinker with the workings of one via an interactive animation .

Figure 3.13 Three Pole DC motor

You'll notice a few things from this -- namely, one pole is fully energized at a time (but two others are "partially" energized). As each brush transitions from one commutator contact to the next, one coil's field will rapidly collapse, as the next coil's field will rapidly charge up (this occurs within a few microsecond). We'll see more about the effects of this later, but in the meantime you can see that this is a direct result of the coil windings' series wiring:

Figure 3.14 DC Motor

The use of an iron core armature (as in the Mabuchi, above) is quite common, and has a number of advantages. First off, the iron core provides a strong, rigid support for the windings -- a particularly important consideration for high-torque motors. The core also conducts heat away from the rotor windings, allowing the motor to be driven harder than might otherwise be the case. Iron core construction is also relatively inexpensive compared with other construction types. But iron core construction also has several disadvantages. The iron armature has a relatively high VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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inertia which limits motor acceleration. This construction also results in high winding inductances which limit brush and commutator life. In small motors, an alternative design is often used which features a 'coreless' armature winding. This design depends upon the coil wire itself for structural integrity. As a result, the armature is hollow, and the permanent magnet can be mounted inside the rotor coil. Coreless DC motors have much lower armature inductance than iron-core motors of comparable size, extending brush and commutator life.

3.11 H-BRIDGE:

Figure 3.15: Circuit of 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. The two basic states of a H-bridge. The term "H-bridge" is derived from the typical graphical representation of such a circuit. 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 applied across the motor. By opening S1 and S4 switches and closing S2 and S3 switches, this voltage is reversed, allowing reverse operation of the motor. Using the nomenclature above, the switches S1 and S2 should never be closed c losed at the same time, as this would cause a short circuit on the input voltage source. The same applies to the switches S3 and S4. This condition is known as s hoot-through. hoot-through.


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3.11.1 OPERATION: 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 s ummarizes operation. S1 S2 S3 S4 Result

1

0

0

1

Motor moves right

0

1

1

0

Motor moves left

0

0

0

0

Motor free runs

0

1

0

1

Motor brakes

Table 3.3: H-Bridge

3.11.2 H-BRIDGE DRIVER: The switching property of this H-Bridge can be replace by a Transistor or a Relay or a Mosfet or even by an IC. Here we are replacing this with an IC named L293D as the driver whose description is as given below.

3.11.3 FEATURES: •

600mA OUTPUT CURRENT CAPABILITY

•

PER CHANNEL

•

1.2A PEAK OUTPUT CURRENT (non repetitive)

•

PER CHANNEL

•

ENABLE FACILITY

•

OVERTEMPERATURE PROTECTION

•

LOGICAL "0" INPUT VOLTAGE UP TO 1.5 V

•

(HIGH NOISE IMMUNITY)

•

INTERNAL CLAMP DIODES


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3.11.4 DESCRIPTION: The Device is a monolithic integrated high voltage, high current four channel driver designed to accept standard DTL or TTL logic levels and drive inductive loads (such as relays solenoids, DC and stepping motors) and switching power transistors. To simplify use as two bridges each pair of channels is equipped with an enable input. A separate supply input is provided for the logic, allowing operation at a lower voltage and internal clamp diodes are included. This device is suitable for use in switching applications at frequencies up to 5 kHz. The L293D is assembled in a 16 lead plastic package which has 4 center pins connected together and used for heat sinking The L293DD is assembled in a 20 lead surface mount which has 8 center pins connected together and used for heat sinking. 3.11.5 BLOCK DIAGRAM:

Figure 3.16 Block Diagram of H-bridge

3.11.6 ABSOLUTE MAXIMUM RATINGS

Table 3.4: Absolute Maximum Ratings


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3.11.7 PIN CONNECTIONS

Figure 3.17 PIN connections

3.12 MICROCONTROLLERS: Microprocessors and microcontrollers are widely used in embedded systems products. Microcontroller is a programmable device. A microcontroller has a CPU in addition to a fixed amount of RAM, ROM, I/O ports and a timer embedded all on a single chip. The fixed amount of on-chip ROM, RAM and a nd number of I/O ports in microcontrollers makes them ideal for many applications in w hich cost and space are critical. The Intel 8052 is Harvard architecture, single chip microcontroller (µC) which was developed by Intel in 1980 for use in embedded systems. It was popular in the 1980s and early 1990s, but today it has largely been superseded by a vast range of enhanced devices with 8052-compatible processor cores that are manufactured by more than 20 independent manufacturers including Atmel, Infineon Technologies and Maxim Integrated Products. 8052 is an 8-bit processor, meaning that the CPU can work on only 8 bits of data at a time. Data larger than 8 bits has to be broken into 8-bit pieces to be processed by the CPU. 8052 is available in different memory types such as a s UVEPROM, Flash and NV-RAM. The present project is implemented on Keil uVis ion. In order to program the device, proload tool has been used to burn the program onto the microcontroller . VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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3.12.1 ARDUINO: Arduino is an open source electronics prototyping platform based on flexible, easy-touse hardware and software. It’s intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments. It’s an open-source physical computing platform based on a microcontroller board, and a development environment for writing software for the board. In simple words, Arduino is a small microcontroller board with a USB plug to connect to your computer and a number of connection sockets that can be wired up to external electronics, such as motors, relays, light sensors, laser diodes, loudspeakers, microphones, etc., They can either be powered through the USB connection from the computer or from a 9V battery. They can be controlled from the computer or programmed by the computer and then disconnected and allowed to work independently. Anyone can buy this device through online auction site or search engine. Since the Arduino is an open-source hardware designs and create their own clones of the Arduino and sell them, so the market for the boards is competitive c ompetitive .


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CHAPTER-4 WIRELESS COMMUNICATION 4.1 WIRELESS COMMUNICATION INTRODUCTION: 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. To provide background information in understanding wireless technology, the electromagnetic spectrum is first presented and some basic terminology defined.

4.1.1 WHAT IS RF? Radio frequency (RF) is a frequency or rate of oscillation within the range of about 3 Hz 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 that most mechanical systems c an respond to, RF usually refers to oscillations in electrical circuits or electromagnetic radiation

4.1.2 WHAT IS THE NEED FOR RF? Radio frequency is a frequency or rate of oscillation within the range of about 3 Hz

to 300 GHz. This range corresponds to t o frequency of alternating current electrical signals used to produce and detect radio waves since most of this range is beyond the vibration rate that most mechanical systems c an 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. VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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4.2 PROPERTIES OF RF: Electrical currents that oscillate at RF have special properties not shared by direct current signals. 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 used in electric arc welding. Another special property is an electromagnetic force that drives the RF current to the surface of conductors, known as the skin effect. Another property is the ability to appear to flow through paths that contain insulating material, like the dielectric insulator of a capacitor. The degree of effect of these properties depends on the frequency of the signals.

4.3 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 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. In the atmosphere or in outer space, if f is is the frequency in me gahertz and sis the wavelength in meters, then s = 300/ f . The frequency of an RF signal is inversely proportional to the wavelength of

the EM field to which it corresponds. At 9 kHz, the free-space wavelength is approximately 33 kilometers (km) or 21 miles (mi). At the highest radio frequencies, the EM wavelengths measure approximately one millimeter (1 mm). 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. Many types of wireless devices make use of RF fields. Cordless and cellular telephone, radio and television broadcast stations, satellite communications systems, and two-way radio services all operate in the RF spectrum.


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Some wireless devices operate at IR or visible-light frequencies, whose electromagnetic wavelengths are shorter than those of RF fields.

4.4

DIFFERENT

RANGES

PRESENT

IN

RF

AND

APPLICATIONS IN THEIR RANGES Frequency

Frequency range

Distance

Uses

Extremely low frequency

3 to 30 Hz

10,000 km to 100,000 km

Directly audible when converted to sound, communication with submarines

Super low frequency

Ultra low frequency

Very low frequency

Directly audible when converted to sound, AC power grids (50 hertz and 60 hertz)

30 to 300 Hz

1,000 km to 10,000 km

300 to 3000 Hz

100 km 1,000 km

3 to 30 kHz

10 km to 100 km

Directly audible when converted to sound (below ca. 18-20 kHz; or "ultrasound" 20-30+ kHz)

to

Directly audible when converted to sound, communication with mines

Low frequency

30 to 300 kHz

1 km to 10 km

AM broadcasting, beacons, low FER

Medium frequency

300 to 3000 kHz

100 m to 1 km

Navigational beacons, AM broadcasting, maritime and aviation communication

High frequency

3 to 30 MHz

10 m to 100 m

Shortwave, amateur radio, citizens' band radio

Very high frequency

30 to MHz

1 m to 10 m

FM broadcasting broadcast television, aviation, GPR

Ultra high frequency

300 to 3000 MHz

300

3 to 30 GHz

Super high frequency

Extremely high frequency

30 to 300 GHz

navigational

10 cm to 100 cm

Broadcast television, mobile telephones, , wireless networking, microwave ovens, GPR

1 cm to 10 cm

Wireless networking, satellite links, microwave links, Satellite television, door openers.

1 mm to 10 mm

Microwave data links, radio astronomy, remote sensing, advanced weapons systems, advanced security scanning

Table 4.1: Different RF ranges and Applications


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4.5 RF TRANSMITTER STT-433MHz:

Figure 4.1: RF Transmitter

4.5.1 PIN DESCRIPTION: GND 

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DATA 

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VCC 

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ANT 

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4.5.2 FACTORS INFLUENCED TO CHOOSE STT-433MHz: 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 batterypowered applications.


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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 STT433 suitable for high volume applications.

FEATURES: •

433.92 MHz Frequency

•

Low Cost

•

1.5-12V operation

•

Small size

APPLICATION:

Figure 4.2 Applications

The typical connection shown in the above figure cannot work exactly at all times because there will be no proper synchronization between the transmitter and the microcontroller unit. i.e., whatever the microcontroller sends the data to the transmitter, the transmitter is not able to accept t his data as this will be not in the radio frequency range. Thus, we need an intermediate device which can accept the input from the microcontroller, process it in the range of radio frequency range and then send it to the transmitter. Thus, an encoder is used. VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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4.6 RF RECEIVER STR-433 MHZ:

Figure 4.3 RF Receiver

The data is received by the RF receiver from the 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 4.4: PIN Diagram of RF receiver

PIN-OUT: ANT 

Antenna input.

GND 

Receiver Ground. Connect to ground plane.


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VCC (5V) 

VCC pins are electrically connected and provide operating voltage for the receiver. VCC can be applied to either or both. VCC should be bypassed with a .1µF 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.

Figure 4.5: Digital Data PIN


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4.7 RF 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.

4.8 RF 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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4.9 INTERFACING OF RF TRANSMITTER WITH AT89S52:

4.10 INTERFACING OF RF RECEIVER WITH ARDUINO:


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CHAPTER 5 MEMS TECHNOLOGY 5.1 MEMS INTRODUCTION: MEMS stand for Micro-Electro Mechanical Systems. MEMS techniques allow both electronic circuits and mechanical devices to be manufactured on a silicon chip, similar to the process used for integrated circuits. This allows the construction of items such as sensor chips with built-in electronics that are a fraction of the size that was previously possible. Micro electromechanical systems (MEMS) are small integrated devices or systems that combine electrical and mechanical components. They range in size from the sub micrometer (or sub micron) level to the millimeter level and there can be any number, from a few to millions, in a particular system. MEMS extend the fabrication techniques developed for the integrated circuit industry to add mechanical elements such as beams, gears, diaphragms, and springs to devices. Examples

of

MEMS

device

applications

include

inkjet-printer

cartridges, accelerometers miniature robots, micro engines, locks, inertial sensors, micro transmissions, micro mirrors, micro actuators, optical scanners, fluid pumps, transducers, and chemical, pressure and flow sensors. New applications are emerging as the existing technology is applied to the miniaturization and integration of conventional devices. These systems can sense, control, and activate mechanical processes on the micro scale, and function individually or in arrays to generate effects on the macro scale. The micro fabrication technology enables fabrication of large arrays of devices, which individually perform simple tasks, but in combination can accomplish complicated functions.


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Figure 5.1 Components of MEMS

The MEMS industry has an estimated $10 billion market, and with a projected 10-20% annual growth rate, it is estimated to have a $34 billion market in 2002 [1]. Because of the significant impact that MEMS can have on the commercial and defense markets, industry and the federal government have both taken a special interest in their development. IC fabrication is dependent upon sensors to provide input from the surrounding environment, just as control systems need actuators (also referred to as transducers) in order to carry out their desired functions. Due to the availability of sand as a material, much effort was put into developing Si processing and characterization tools. These tools are now being used to advance transducer technology. Today's IC technology far outstrips the original sensors and actuators in performance, cost and size. Around 1982, the term micromachining came into use to designate the fabrication of micromechanical parts (such as pressure-sensor diaphragms or accelerometer suspension beams) for Si micro sensors. The micromechanical parts were fabricated by selectively etching areas of the Si substrate away in order to leave behind the desired geometries. Isotropic etching of Si was developed in the early 1960s for transistor fabrication. Anisotropic etching of Si then came about in 1967. Various etch-stop techniques were subsequently developed to provide further process flexibility. These techniques also form the basis of the bulk micromachining processing techniques. Bulk micromachining designates the point at which the bulk of the Si substrate is etched away to leave behind the desired micromechanical elements [3]. Bulk micromachining has remained a powerful technique for the fabrication of micromechanical elements. However, the need for flexibility in device design and VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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performance improvement has motivated the development of new concepts and techniques for micromachining. Among these is the sacrificial layer technique, first demonstrated in 1965 by Nathanson and Wickstrom [15], in which a layer of material is deposited between structural layers for mechanical separation and isolation. This layer is removed during the release etch to free the structural layers and to allow mechanical devices to move relative to the substrate. A layer is releasable when a sacrificial layer separates it from the substrate. The application of the sacrificial layer technique to micromachining in 1985 gave rise to surface micromachining. Fabrication Technologies:

The

three

characteristic

features

of

MEMS

fabrication

technologies

are

miniaturization, multiplicity, and microelectronics. Miniaturization enables the production of compact, quick-response devices. Multiplicity refers to the batch fabrication inherent in semiconductor processing, which allows thousands or millions of components to be easily and concurrently fabricated. Microelectronics provides the intelligence to MEMS and allows the monolithic merger of sensors, actuators, and logic to build closed-loop feedback components and systems. The successful miniaturization and multiplicity of traditional electronics systems would not have been possible without IC fabrication technology. Therefore, IC fabrication technology, or micro fabrication, has so far been the primary enabling technology for the development of MEMS. Micro fabrication provides a powerful tool for batch processing and miniaturization of mechanical systems into a dimensional domain not accessible by conventional (machining) techniques. Furthermore, micro fabrication provides an opportunity for integration of mechanical systems with electronics to develop high-performance closed-loop-controlled MEMS. Advances in IC technology in the last decade have brought about corresponding progress in MEMS fabrication processes. Manufacturing processes allow for the monolithic integration of micro-electromechanical structures with driving, controlling, and signal-processing electronics. This integration promises to improve the performance of micromechanical devices as well as reduces the cost of manufacturing, packing and instrumenting these devices. VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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Applications of MEMS: •

Pressure sensors

•

Accelerometers

•

Inertial sensors

•

Micro engines

5.2 ACCELEROMETER An accelerometer is an apparatus, either mechanical m echanical or electromechanical, for measuring acceleration or deceleration - that is, the rate of increase or decrease in the velocity of a moving object. Accelerometers are used to measure the efficiency of the braking systems on road and rail vehicles; those used in aircraft and spacecraft can determine accelerations in several directions simultaneously. There are also accelerometers for detecting vibrations in machinery.

Figure 5.2: Accelerometer

The types of sensor used to measure acceleration, shock, or tilt include piezo film, 5.2.1 THE PIEZO ELECTRIC ACCELEROMETER:

Among the desirable features of the piezoelectric (PE) accelerometer are accuracy, durability, large dynamic range, ease of installation, and long life span. Although these devices cost more than other types, in many situations their benefits outweigh the higher price. To provide useful data, PE accelerometers require proper signal conditioning circuitry. We will briefly review the important characteristics of a PE accelerometer and circuit techniques for signal conditioning. In particular, we will examine an interface that will allow the accelerometer output's magnitude and frequency to be measured by a microcontroller unit (MCU).


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Figure 5.3 Piezo Electric Accelerometer

The PE accelerometer uses an internal PE element coupled with a loading mass to form a single-degree-of-freedom "mass-spring" system. The accelerometer is a charge-sensitive device; an instantaneous change in stress on the internal PE element produces a charge at the accelerometer's output terminals that is proportional to the applied acceleration. 5.2.2 G-WHIZ:

The ADXL202 two-axis ý2- g accelerometer from Analog Devices is a good example of a micro machine that’s making waves in the commercial market. More sensitive than earlier airbag designs, it’s well suited for novel applications like two-axis tilt sensing and inertial navigation. For instance, Microsoft is using the ’202 in their new Freestyle Pro game controller, which senses body motion. The basic principle of micro machined accelerometers is simple enough. A tethered or "sprung" mass is forced into motion by an applied acceleration. The distance that the mass moves, and thus the acceleration, is determined by differential capacitance, as shown in figure.

Figure 5.4—G-Whiz

The principle may be simple, but the implementation is incredible, given the intricacy of crafting it in silicon. Consider that the smallest detectable capacitance VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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change, 20 zF (yes, that’s "z" as in 10–21 F), corresponds to a 2-pm deflection! But while it’s capable of resolving mere m g’s (thousandths of a g), the device can take a 500–1000-g hit and keep on ticking. The use of a standard IC process means the same die can integrate signalconditioning and digitizing circuits, dispensing with the design hassles of dealing with low-level analog signals. That makes the ADXL202 real easy to use. Just add power (3–5.25 V, a mere 1 mA at that) and have at it with your favorite MCU or PLD. 5.2.3 SURFACE MICRO-MACHINED ACCELEROMETERS:

In recent years, silicon micro-machined sensors have made tremendous advances in terms of cost and level of on-chip integration for measurements such as acceleration and/or vibration. These products provide the sensor and the signal conditioning circuitry on chip, and require only a few external components. Some manufacturers have taken this approach one step further by converting the analogue output of the analogue signal conditioning to a digital format such as duty cycle. This method not only lifts the burden of designing fairly complex analogue circuitry for the sensor, but also reduces cost and board area. Micro-machined accelerometers are now being incorporated into products such as joysticks and airbags, applications that were previously impossible due to sensor price and or size. A surface micro-machined device consists of springs, masses, and motion-sensing components. These sensors are made with the standard IC processing techniques used in wafer fabrication facilities

Figure 5.5: Surface Micro-Machined Accelerometer


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5.3

INTERFACING

OF

ECE

MEMS

SENSOR

WITH

MICROCONTROLLER:


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CHAPTER-6 MICROCONTROLLER 6.1 MICROCONTROLLERS INTRODUCTION: Microprocessors and microcontrollers are widely used in embedded systems products. Microcontroller is a programmable device. A microcontroller has a CPU in addition to a fixed amount of RAM, ROM, I/O ports and a timer embedded all on a single chip. The fixed amount of on-chip ROM, RAM and a nd number of I/O ports in microcontrollers makes them ideal for many applications in w hich cost and space are critical. The Intel 8052 is Harvard architecture, single chip microcontroller (µC) which was developed by Intel in 1980 for use in embedded systems. It was popular in the 1980s and early 1990s, but today it has largely been superseded by a vast range of enhanced devices with 8052-compatible processor cores that are manufactured by more than 20 independent manufacturers including Atmel, Infineon Technologies and Maxim Integrated Products.

6.2 FEATURES: • Compatible with MCS-51® Products • 8K Bytes of In-System Programmable (ISP) Flash Memory • 4.0V to 5.5V Operating Range • Fully Static Operation: 0 Hz to 33 MHz • Three-level Program Memory Lock • 256 x 8-bit Internal RAM • 32 Programmable I/O Lines • Three 16-bit Timer/Counters • Eight Interrupt Sources • Full Duplex UART Serial Channel • Low-power Idle and Power-down Modes • Interrupt Recovery from Power-down Mode • Watchdog Timer • Dual Data Pointer • Power-off Flag VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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The AT89S52 is a low-power, high-performance high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory. The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry- standard 80C51 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 in-system programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications.

PIN DIAGRAM OF AT89S52:

Figure 6.1 AT89S52 PIN Diagram

6.3 PIN DESCRIPTIONS OF AT89S52 VCC

Supply voltage. GND

Ground. VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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Port 0

Port 0 is an a n 8-bit open drain bidirectional I/O port. Port 1

Port 1 is an 8-bit bidirectional I/O port with internal pullups. The Port 1 output buffers can sink/source four TTL inputs.

Table 6.1: Port 1

Port 2

Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 2 output buffers can sink/source four TTL inputs. Port 2 also receives the high-order address bits and some control signals during Flash programming and verification. Port 3

Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 3 output buffers can sink/source four TTL inputs. Port 3 also serves the functions of various special features of the AT89S52, as shown in the following table. Port 3 also receives some control signals for Flash programming and verification.


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Table 6.2: Port 3

RST

Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. ALE/PROG

Address Latch Enable (ALE) is an output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. PSEN

Program Store Enable (PSEN) is the read strobe to external program memory. When the AT89S52 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory. EA/VPP External Access Enable, EA must be strapped to GND in order to enable the device

to fetch code from external program memory locations starting at 0000H up to FFFFH. This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming. XTAL1

Input to the inverting oscillator amplifier and input to the internal clock operating circuit. XTAL2

Output from inverting oscillator amplifier.


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SFRs (Special Function Registers): SFRs are a kind of control table used for running and monitoring microcontroller’s operating. Each of these registers, even each bit they include, has its name, address in the scope of RAM and clearly c learly defined purpose .

A Register (Accumulator) This is a general-purpose register which serves for storing intermediate results during operating

B Register: B register is used during multiply and divide operations which can be performed only upon numbers stored in the A and a nd B registers.

6.4 ARDUINO Arduino interface boards provide the engineers, artists, designers, hobbyists and

anyone who tinker with technology with a low-cost, easy-to-use technology to create their creative, interactive objects, useful projects etc., A whole new breed of projects can now be built that can be controlled from a computer.

Figure 6.2 Arduino board

Arduino is a open source electronics prototyping platform based on flexible, easy-to-use hardware and software. It’s intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments. It’s an open-source physical computing platform based on a microcontroller board, and a development environment for writing software for the board. VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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In simple words, Arduino is a small microcontroller board with a USB plug to connect to your computer and a number of connection sockets that can be wired up to external electronics, such as motors, relays, light sensors, laser diodes, loudspeakers, microphones, etc., They can either be powered through the USB connection from the computer or from a 9V battery. They can be controlled from the computer or programmed by the computer and then disconnected and allowed to work independently. Anyone can buy this device through online auction site or search engine. Since the Arduino is an open-source hardware designs and create their own clones of the Arduino and sell them, so the market for the boards is competitive. The name “Arduino” is reserved by the original makers. However, clone Arduino designs often have the letters “duino” on the end of their name, for example, Freeduino or DFRduino. The software for programming your Arduino is easy to use and also freely available for Windows, Mac, and LINUX computers at no cost.

ARDUINO Board Pin diagram

Figure 6.3 Arduino Pin Diagram

6.4.1 THE ARDUINO PIN DESCRIPTION: •

VIN: The input voltage to the t he Arduino board when it's using us ing an external power source (as opposed to 5 volts from the USB connection or other regulated power source). You can supply voltage through this pin, or, if supplying voltage via the power jack, access it through this pin.


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5V: The regulated power supply used to power the microcontroller and other components on the board. This can come either from VIN via an on-board regulator, or be supplied by USB or another regulated 5V supply.

•

3V3: A 3.3 volt supply generated by the on-board regulator. Maximum current draw is 50 mA.

•

GND. Ground pins.

•

Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data. These pins are connected to the corresponding pins of the ATmega8U2 USB-to-TTL Serial chip.

•

PWM: 3, 5, 6, 9, 10, and 11. Provide 8-bit PWM output with the analog Write () function.

•

LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it's off.

•

The Uno has 6 analog a nalog inputs, each of which provides 10 bits of resolution.

•

Each of the 14 digital pins on the Uno can be used as an input or output, using pin Mode(), digital digital Write(), and digital Read() functions

Digital pins: •

Pins 0 – 7: PORT D [0:7]

•

Pins 8 – 13: PORT B [0:5]

•

Pins 14 – 19: PORT C [0:5] (Arduino analog pins 0 – 5)

•

digital pins 0 and 1 are RX and TX for serial communication

•

digital pin 13 connected to the base board LED

Digital Pin I/O Functions: •

pin Mode( pin, mode)

•

Sets pin to INPUT or OUTPUT mode

•

digital Write(pin, value)

•

Sets pin value to LOW or HIGH (0 or 1)


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int value = digital Read(pin)

•

Reads back pin value (0 or 1)

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Analog input: •

Analog input pins: 0 – 5

•

Analog input functions int Val = analog Read( pin)

Analog output: •

Generates a PWM output on digital pin (3, 5, 6, 9, 10, 11)

•

Analog input functions Analog Write ( pin, value)

6.5 ATMEGA 328 Microcontrollers The ATmega88 through ATmega328 microcontrollers are said by Atmel to be the upgrades from the very popular ATmega8. They are pin compatible, but not functionally compatible. The ATmega328 has 32kB of flash, where the ATmega8 has 8kB. Other differences are in the timers, additional SRAM and EEPROM, the addition of pin change interrupts, and a di vide by 8 presale for the system clock. The schematic below shows the Atmel ATmega328 circuit as it was built on the test board. The power supply is common and is shared between all of the microcontrollers on the board. The ATmega328 is in a minimal circuit. It is using its internal 8 MHz RC oscillator osci llator (divided by 8). The boot loader is programmed using the ISP programming connector, and the Arduino sketches are uploaded via the 6-pin header. Be aware that programming the Arduino boot loader into the ATmega88, ATmega168, or ATmega328 microcontroller will change the clock fuses, requiring the addition of an external crystal. The crystal shown on the schematic is only required when the ATmega328 is going to be used as an Arduino, although it may be desired in any real world application. I t ypically run them at 16 MHz, but they will run as high as 20 MHz.


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PIN DIAGRAM:

Figure 6.4: AT mega PIN diagram

6.5.1 PIN DESCRIPTIONS: VCC: Digital supply voltage GND: Ground Port B (PB7:0) XTAL1/XTAL2/TOSC1/TOSC2

Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port B output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port B pins that are externally pulled low will source current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset condition becomes active, even if the clock is not running. Depending on the clock selection fuse settings, PB6 can be used as input to the inverting Oscillator amplifier and input to the internal clock operating circuit. Depending on the clock selection fuse settings, PB7 can be used as output from the inverting Oscillator amplifier. If the Internal Calibrated RC Oscillator is used as chip clock source, PB7.6 is used as TOSC2.1 input for the Asynchronous Timer/Counter2 if the AS2 bit in ASSR is set.


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Port C (PC5:0)

Port C is a 7-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The PC5..0 output buffers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port C pins that are externally pulled low will source current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset condition becomes active, even if the clock is not running . PC6/RESET

If the RSTDISBL Fuse is programmed, PC6 is used as an I/O pin. Note that the electrical characteristics of PC6 differ from those of the other pins of Port C. If the RSTDISBL Fuse is unprogrammed, PC6 is used as a Reset input. A low level on this pin for longer than the minimum pulse length will generate a Reset, even if the clock is not running. Port D (PD7:0)

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

AVCC is the supply voltage pin for the A/D Converter, PC3:0, and ADC7:6. It should be externally connected to VCC, even if the ADC is not used. If the ADC is used, it should be connected to VCC through a low-pass f ilter. AREF

AREF is the analog reference pin pi n for the A/D Converter. ADC7:6 (TQFP and QFN/MLF Package Only)

In the TQFP and QFN/MLF package, ADC7:6 serve as analog inputs to the A/D converter. These pins are powered from the analog supply and serve as 10-bit ADC channels.


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CHAPTER-7 SOFTWARE DETAILS 7.1 KEIL SOFTWARE: Keil compiler is software used where the machine language code is written and compiled. After compilation, the machine source code is converted into hex code which is to be dumped into the microcontroller for further processing. Keil compiler also supports C language code.

STEPS TO WRITE AN ASSEMBLY LANGUAGE PROGRAM IN KEIL AND HOW TO COMPILE IT: 1. Install the Keil Software in the PC in any of the drives. 2. After installation, an icon will be created with the name “Keil uVision3”. Just drag this icon onto the desktop so that it becomes easy whenever you try to write programs in keil. 3. Double click on this icon to start the keil compiler. 4. A page opens with different options in it showing the project workspace at the leftmost corner side, output window in the bottom and an ash colored space for the program to be written. 5. Now to start using the keil, click on the option “project”. 6. A small window opens showing the options like new project, import project, open project etc. Click on “New project”. 7. A small window with the title bar “Create new project” opens. The window asks the user to give the project name with which it should be created and the destination location. The project can be created in any of the drives available. You can create a new folder and then a new file or can create directly a new file. 8. After the file is saved in the given destination location, a window opens where a list of vendors will be displayed and you have to select the device for the target you have created.


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9. The most widely used vendor is Atmel. So click on Atmel and now the family of microcontrollers manufactured by Atmel opens. You can select any one of the microcontrollers according to the requirement. 10. When you click on any one of the microcontrollers, the features of that particular microcontroller will be displayed on the right si de of the page. Click on this microcontroller and have a look at its features. Now click on “OK” to select this microcontroller. 11. A small window opens asking whether to copy the startup code into the file you have created just now. Just J ust click on “No” to proceed further. 12. Now you can see the TARGET and SOURCE GROUP created in the project workspace. 13. Now click on “File” and in that “New”. A new page opens and you can start writing program in it. 14. After the program is completed, save it with any name but with the .asm extension. Save the program in the file fi le you have created earlier. 15. You can notice that after you save the program, the predefined keywords will be highlighted in bold letters. 16. Now add this file to the target by giving a right click on the source group. A list of options open and in that select “Add files to the source group”. Check for this file where you have saved and add it. 17. Right click on the target and select the first option “Options for target”. A window opens with different options like device, target, output etc. First click on “target”. 18. Since the set frequency of the microcontroller is 11.0592 MHz to interface with the PC, just enter this frequency value in the Xtal (MHz) text area and put a tick on the Use on-chip ROM. This is because the program what we write here in the keil will later be dumped into the microcontroller and will be stored in the inbuilt ROM in the microcontroller. 19. Now click the option “Output” and give any name to the hex file to be created in the “Name of executable” text area and put a tick to the “Create HEX file” option present in the same window. The hex file can be created in any of the drives. You can change the folder by clicking on “Select folder for Objects”.


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20. Now to check whether the program you have written is errorless or not, click on the icon exactly below the “Open file” icon which is nothing but Build Target icon. You can even use the shortcut key F7 to compile the program written. 21. To check for the output, there are several windows like serial window, memory window, project window etc. Depending on the program you have written, select the appropriate window to see the output by entering into debug mode. 22. The icon with the letter l etter “d” indicates the debug mode. 23. Click on this icon and now click on the option “View” and select the appropriate window to check for the output. 24. After this is done, click the icon “debug” again to come out of the debug mode. 25. The hex file created as shown earlier will be dumped into the microcontroller with the help of another software called Proload.

7.2 PROLOAD: Proload is software which accepts only hex files. Once the machine code is converted into hex code, that hex code has to be dumped into the microcontroller placed in the programmer kit and this is done by the Proload. Programmer kit contains a microcontroller on it other than the one which is to be programmed. This microcontroller has a program in it written in such a way that it accepts the hex file from the keil compiler and dumps this hex file into the microcontroller which is to be programmed. As this programmer kit requires power supply to be operated, this power supply is given from the power supply circuit designed above. It should be noted that this programmer kit contains a power supply section in the board itself but in order to switch on that power supply, a source is required. Thus this is accomplished from the power supply board with an output of 12volts or from an adapter connected to 230 V AC. 1. Install the Proload Software in the PC. 2. Now connect the Programmer kit to the t he PC (CPU) through serial cable. 3. Power up the programmer kit from the ac supply through adapter. VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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4. Now place the microcontroller in the GIF socket provided in the programmer kit. 5. Click on the proload icon in the PC. A window appears providing the information like Hardware model, com port, device type, Flash size etc. Click on browse option to select the hex file to be dumped into the microcontroller and then click on “Auto program” to program the microcontroller with that particular hex file. 6. The status of the microcontroller can be seen in the small status window in the bottom of the page. After this process is completed, remove the microcontroller from the programmer kit and place it in your system board. Now the system board behaves according to the program written in the microcontroller.

7.3 ARDUINO SOFTWARE TOOLS Arduino and Arduino Mega Software and Drivers Installation This describes the installation of the Arduino IDE Development software and drivers for the Windows Operating System. The images and description is based on installation under Windows XP, but the process should be similar for Vista and Windows 7. First we need to get the latest version of the Arduino software this can be downloaded from the Arduino website STEP 1:

Next, plug in your Arduino board to your computer with a USB cable and wait while Windows detects the new device. Windows will fail to detect the device as it doesn't know where the drivers are stored. You will get an error similar to the one right. Select the Install from a list or specific location (Advanced) option and click next next


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STEP 2:

Now choose the location that the Arduino drivers are stored in. This will be in a subfolder called drivers in your Arduino directory


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STEP3:

After selecting next you may get a message like the one shown right. Select Continue Anyway

STEP 4:

Windows should now have found the Arduino drivers. Click Finish to complete the installation


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STEP 5:

The computer communicates with the Arduino board via a special serial port chip

built into the Arduino board. The Arduino IDE software needs to know the serial port number that Windows has just allocated to it Open the Windows Control Panel and select the System app. Click on the Hardware tab and then on the Device Manager button. Click on the Ports (COM and LPT) option and note what COM port has been allocated to the Arduino Board.

STEP 6:

Next, run the Arduino IDE application, which will be in c:\program files\arduino0021 or similar Click on Tools | Serial Port and select the port number from above


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STEP 7:

Next click on Tools | Board and select the type of board that you have

STEP 8:

Now try opening the Simple program from the example directory within the Arduino IDE, Verify/Compile it and upload it to your board. You should see the TX and RX leds on the board flash showing you that it is working. Finally the built in LED connected to Pin 13 will flash. That’s your first program running

Create a shortcut to the Arduino IDE and place it on your desktop VISHWA BHARATHI INSTITUTE OF TECHNOLOGY & SCIENCES (VBITS)

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CHAPTER 8 SCHEMATIC REPRESENTATION 8.1 SCHEMATIC REPRESENTATION OF TRANSMITTER


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8.2 SCHEMATIC REPRESENTATION OF RECEIVER:


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RF RECEIVER

MOBILE JAMMER WITH METAL DETECTOR


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CHAPTER-9 APPLICATIONS AND ADVANTAGES 9.1 APPLICATIONS: 

Defense: This project is useful in bomb detection and surveillance areas.



Temples: A metal detection robot is used at sacred places & crowded areas

like shopping malls instead of men power power . 

VIP security: A bomb diffusion robot with a CCTV camera can be used at

VIP’s houses for their security. sec urity. 

Terrorist prone areas.



Instead of manpower to detect landmines in combing operations, this project is much helpful for mines detection.

9.2 ADVANTAGES: 

Spontaneous output.



Long range.



Not light sensitive.



Line of sight not required.



Not as sensitive to t o weather/environmental conditions


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CHAPTER-10 RESULT TRANSMITTER

INPUT:

RECEIVER

LCD DISPLAY:


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OUTPUT:

WHEN METEL DETECTED: INPUT

OUTPUT

MOBILE JAMMER ACITVATED WHEN METAL DETECTED:


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CHAPTER- 11 CONCLUSION & FUTURE SCOPE 10.1 CONCLUSION This project presents the movement of the robot using Hand gesture technology which runs on the 9V power supply. This project is been designed and implemented with ARDUINO MCU in embedded system domain. 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.

10.2 FUTURE SCOPE 

Could be made to work on solar energy instead of battery source.



For more spontaneous output including visual guidance, an image capturing device of high resolution like movable camera c ould be fixed to the robot.



The voice recognition security may also be developed in future.


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REFERENCES:

1. Www. howstuffworks.com 2. Embedded System by Raj Kamal 3. 8051 Microcontroller and Embedded Systems by Mazzidi 4. Electronics Maker. 5. Electronics for you 6. Electrikindia 7. www.wikipedia.com 8. www.Electronic projects.com


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APPENDIX SOURCE CODE TRANSMITTER: #include #include"I2C_MEM.c" #include"LCD4.h" sbit sbit sbit sbit

frw=P2^7; lft=P2^6; rht=P2^5; bck=P2^4;

void main() { LCD_init(); LCD_puts(0x80," I2C

MEMS TEST ");

MEMS_Init(); LCD_puts(0x80,"

Mem inited

");

while (1) { x=RrByte_MEMS(0x00); y=RrByte_MEMS(0x01); z=RrByte_MEMS(0x02); Robo_Movements(x,y); } }

Robo_Movements(unsigned Robo_Movements(unsi gned char f_b,unsigned char l_r) { if((f_b>15&&f_b<35)) { LCD_puts(0x80," FORWARD "); frw=0; return; } else if(f_b<50&&f_b>35) { LCD_puts(0x80," BACKWARD "); bck=0; return;

} else if(l_r>15&&l_r<35) { LCD_puts(0x80," lft=0; return; } else if(l_r<50&&l_r>35) { LCD_puts(0x80," rht=0; return; } else if((f_b<10 && l_r<10) { LCD_puts(0x80," } }

LEFT

");

RIGHT

");

|| (f_b>100 && l_r>100)) STOP

RECEIVER: //RF//////////////////// const int sw1=1; const int sw2=2; const int sw3=3; const int sw4=4; //////////////////////// //H-Bridge////////////// const int h1=5; const int h2=6; const int h3=11; const int h4=12; //////////////////////// int int int int int

sw1State=0; sw2State=0; sw3State=0; sw4State=0; firesensState=0;

void setup() { pinMode(sw1,INPUT); pinMode(sw2,INPUT); pinMode(sw3,INPUT); pinMode(sw4,INPUT); pinMode(h1,OUTPUT); pinMode(h2,OUTPUT); pinMode(h3,OUTPUT);

");

pinMode(h4,OUTPUT); }

void loop() { if(sw1State==LOW) { digitalWrite(h1,HIGH); digitalWrite(h2,LOW); digitalWrite(h3,HIGH); digitalWrite(h4,LOW); } if(sw2State==LOW) { digitalWrite(h1,LOW); digitalWrite(h2,HIGH); digitalWrite(h3,LOW); digitalWrite(h4,HIGH); } if(sw3State==LOW) { digitalWrite(h1,HIGH); digitalWrite(h2,LOW); digitalWrite(h3,HIGH); digitalWrite(h4,HIGH); } if(sw4State==LOW) { digitalWrite(h1,HIGH); digitalWrite(h2,HIGH); digitalWrite(h3,HIGH); digitalWrite(h4,LOW); } }

UG Major Project - Wireless Bomb Detection Robot

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