A MINOR PROJECT REPORT

ON Haptic Proximity Module (HPM)

Submitted in Partial Fulfillment

for the Award of the Degree of Bachelor of Technology

In Department of Electronics & Communication Engineering

Session-2013-2017

Submitted To: Submitted By: Mrs. Shumaila Akbar JEETENDRA KUMAR (H.O.D of ECE Department) (13ECIEC005) SOURABH KUMAR (13ECIECOO8)

DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING COMPUCOM INSTITUTE OF TECHNOLOGY AND MANAGEMENT

SP-5,EPIP RIICO INDS. AREA SITAPURA, JAIPUR-302022 RAJASTHAN TECHNICAL UNIVERSITY KOTA

DECEMBER, 2016

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Candidate Deceleration

I hereby declare that the work, which is being presented in the technical project report, entitled “Haptic Proximity Module (HPM)” in partial fulfillment for the award of the Degree of “bachelor of technology” in Electronics and Communication Engineering submitted to the Department of EC Engineering, CIITM is a record of my own investigations carried under the Guidance of Mr. Deepak Gautam, Mr. Sandeep Jaiswal, Mr. Ajay Kumar Jangid,Mr Komal Saini and Mr. Manish Kumar Gupta. Department of Electronics and Communication Engineering, CIITM. I have not submitted the matter presented in this technical report anywhere for the award of my other Degree. JEETENDRA KUMAR Branch: EC Enrolment No: 13E1CIECM3XP005 Roll No: 13ECIEC005 SOURABH KUMAR Branch: EC Enrolment No: 13E1CIECM3XP008 Roll No: 13ECIEC008 CIITM, Jaipur, Rajasthan, India Supervised By: Mr. Deepak Gautam Mr. Sandeep Jaiswal Mr. Ajay Kumar Jangid Mr. Komal Saini and Head Of Department: Mr. Manish Kumar Gupta Mrs. Shumaila Akbar

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ACKNOWLEDGEMENT

We sincerely acknowledgement with deep sense of gratitude to our project guide Mr. Deepak Gautam for the guidance and encourage she gave us for the preparation of this project without him the project would have been difficult. We are highly obliged to Mrs. Shumaila Akbar, H.O.D. (Electronics & Communication) for her noble spontaneous and timely help that carried out us throughout our Endeavour and finally made a grand success. We also thank Mr. Deepak Gautam, Mr. Sandeep Jaiswal, Mr. Ajay Kumar Jangid, Mr. Manish Kumar Gupta & the staff of our electronics department for all the cooperation and friendly treatment given to us during project. We are also thankful to our colleagues and all those have extended the necessary help during the course of our work.

JEETENDRA KUMAR &

SOURABH KUMAR (ECE VIIIth SEMESTER)

The Haptic Proximity Module (The HPM)

Submitted By:- Sourabh Kumar

Jeetendra Kumar

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COMPUCOM INSTITUTE OF TECHNOLOGY AND MANAGEMENT

CERTIFICATE This is to that the report submitted by JEETENDRA KUMAR & SOURABH KUMAR to the Department of ELECTRONICS & COMMUNICATION, Compucom Institute of Technology and Management, in partial fulfillment the requirement for the award of B.Tech Degree in Electronics and Communication is a bonafied record of the work carried out by them during the year 2016-2017. Project Guide & Project Coordinator Mrs. Shumaila Akbar (Head of the Department ECE) Place: Jaipur

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Abstract

God gifted sense of vision to the human being is an important aspect of our life. But there are some unfortunate people who lack the ability of visualizing things. The visually impaired have to face many challenges in their daily life. The problem gets worse when there is an obstacle in front of them. The Haptic Proximity Module is an innovative Electronics Project designed for visually disabled people for improved navigation. The paper presents a theoretical system concept to provide a smart ultrasonic aid for blind people. The system is intended to provide overall measures – Artificial vision and object detection. The aim of the overall system is to provide a low cost and efficient navigation aid for a visually impaired person who gets a sense of artificial vision by providing information about the environmental scenario of static and dynamic objects around them. Ultrasonic sensors are used to calculate distance of the obstacles around the blind person to guide the user towards the available path. Output is in the form of sequence of beep sound and motor vibrance which the blind person can hear and feel. Keywords: Ultrasonic sensors, visually impaired person, Microcontroller. _____________________________________*****_________________________________

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TABLE OF CONTENTS

1.Introduction ............................................................................................................7 1.1 BACKGROUND ........................................................................................8 1.2 LITRATURE SURVEY ................................................................................9 1.3 Project Outline ..........................................................................................10 1.4 Objective ..................................................................................................11 1.5 Parts Required ............................................................................................11 1.6 CONTRUCTION ......................................................................................12

2.Ultrasonic Sensor ......................................................................................................13 2.1 Introduction ................................................................................................13 2.2 Description of the Ultrasonic Sensor ..............................................................14 2.3 Executive Summary of the Ultrasonic Rangefinder ..........................................20 2.4 Background of the Ultrasonic Rangefinder ......................................................20 2.5 Summary of the Ultrasonic Rangefinder ..........................................................21

3 ATmega 328P ...........................................................................................................22 3.1 Introduction ................................................................................................22 3.2 Key parameters ...........................................................................................22 3.3 Series alternatives ........................................................................................23 3.4 Applications ...............................................................................................23 3.5 Programming ..............................................................................................23

4 7805 VOLTAGE REGULATOR ..................................................................................27 4.1 Introduction .................................................................................................27 4.2 Description ..................................................................................................27 4.3 Example of 7805 Regulator ............................................................................30

5 VIBRATING MOTOR ................................................................................................32 5.1 Introduction ..................................................................................................32 5.2 An Introduction of Vibration Motors ................................................................32 5.3 Precision Microdrives Vibration Motor Ranges .................................................33 5.4 Different Vibration Motor Form Factors ...........................................................35 5.5 Common Vibration Motor Applications And Examples ......................................37 5.6 Operation .....................................................................................................38

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6 CAPACITOR & RESISTOR ........................................................................................40 6.1 Introduction of Capacitor ...............................................................................40 6.2 Operation ....................................................................................................40 6.3 Networks .....................................................................................................41 6.4 Introduction of Resistor .................................................................................42 6.5 Operation ....................................................................................................44 6.6 Ohm's law ...................................................................................................44 6.7 Series and parallel resistors ............................................................................45 6.8 Power dissipation .........................................................................................46

7 PRINTED CIRCUIT BOARD ......................................................................................47 7.1 Introduction .................................................................................................47 7.2 Design .........................................................................................................48 7.3 Pcb Designing and Fabrication Process ............................................................48

8 LED..........................................................................................................................................50 8.1Introduction of LED........................................................................................................50 9 Circuit Diagram And Assembly..............................................................................................51 9.1 Circuit Diagram.......................................................................................................51 9.2 Circuit Assembly.....................................................................................................53 10 Code ........................................................................................................................54 11 Working.................................................................................................................57 12 Pros and Cons ...........................................................................................................58 13 FUTURE SCOPE ......................................................................................................59 CONCLUSION ...........................................................................................................60 REFERENCES ............................................................................................................61

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Table Of Figures Figure 1.1 Block Diagram of Project ……………………………………………………………................................10 Figure 2.1 block diagram of an ultrasonic rangefinder …………………………..….…………....................…15 Figure 2.2 timing chart showing signals designated by curves ……………………..………….................15 Figure 2.3 circuit diagram of a typical differentiation circuit …………………………..……….................16 Figure 2.4 graph showing waveforms of ultrasonic wave signals versus time……………………........18 Figure 2.5 circuit diagram of a known simple oscillator circuit…………………………………. ................19 Figure 2.6 Ultrasonic Ranging Module HC - SR04.............................................................21 Figure 3.1 Pinout of ATmega 48A/PA/88A/PA/168A/PA/328/P in 28-PDIP (datasheet) ……….24 Figure 4.1 Regulated Power Supply Circuit ……………………………………………………............................27 Figure 4.2 Pin Diagram of IC 7805 ………………………………………………………………...............................29 Figure 4.3 7805 Voltage Regulator Circuit Diagram ……………………………………………......................30 Figure 5.1 Brushless Dura Vibe™ Vibration Motor …………………………………………….......................32 Figure 5.2 Different Types of Vibrating Motor ………………………………………..……….......................…34 Figure 5.3 Vibrating Motor ………………………………………………………………………....................................39 Figure 6.1 Capacitor-Plate Separation ……………………………………………………………..............................41 Figure 6.2 Capacitor Series and parallel …………………………………………………………..............................42 Figure 6.3 Resistor ………………………………………………………………………………..........................................43 Figure 6.4 Concept ………………………………………………………………………………..........................................44 Figure 6.5 Resistor Series and parallel …………………………………………………………..............................…45 Figure 6.6 An aluminum-housed power resistor rated for 50 W when heat-sinked …………….......46 Figure 7.1 PCB …………………………………………………………………………………............................................48 Figure 7.2 A board designed in 1967 …………………………………………………………..............................….48 Figure 8.1 Types Of LED...............................................................................................50 Figure 8.2 Construction of A LED.........................................................................................50 Figure 9.1.Breadboard model of The H.P.M. ……………………………………………………..................................51 Figure 9.2 Schametic model of The HPM ………………………………………………………..............................52 Figure 9.3 PCB Model of The HPM …………………………...............................…………………………………...53

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Table List

Table: 1 Key parameters.................................................................................................. 23 Table: 2 Parallel program mode ........................................................................................24 Table: 3 Serial Programming ...........................................................................................25 Table: 4 FUNCTION of 7805 ..........................................................................................28 Table: 5 DESCRIPTION of 7805 .....................................................................................29 Table: 6 Components......................................................................................................30

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| Chapter 1

INTRODUCTION

There are approximately 37 million people across the globe who are blind, over 15 million are from India. Even for the non-visually impaired the congestion of obstacles is sometimes problematic, it’s even worse for the visually impaired. People with visual disabilities are often dependent on external assistance which can be provided by humans, trained dogs, or special electronic devices as support systems for decision making. Existing devices are able to detect and recognize objects that emerge on the floor, but a considerable risk is also includes the objects that are at a sudden depth, or obstacles above waist level or stairs. Thus we were motivated to develop a smart device to overcome these limitations. The most common tool that the blind currently use to navigate is the standard white cane. We decided to modify and enhance the walking cane, since blind are only able to detect objects by touch,hear or by cane. The user sweeps the cane back and forth in front of them. When the cane hits an object or falls off of the edge of a stair, the user then becomes aware of the obstacle –sometimes too late. We accomplished this goal by adding ultrasonic sensors that provided information about the environment to the user through diffrent type of buzzer sounds and vibration feedback. The main component of this system is the Ultrasonic module with Atmega 328p-pu microprocessor.

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1.1 BACKGROUND Vision is the most important part of human physiology as 83% of information human being gets from the environment is via sight. The 2011 statistics by the World Health Organization (WHO) estimates that there are 285 million people in world with visual impairment, 39 billion of which are blind and 246 with low vision. The traditional and oldest mobility aids for persons with visual impairments are the walking cane (also called white cane or stick) and guide dogs. The most important drawbacks of these aids are necessary skills and training phase, range of motion and very little information conveyed. With the rapid advances of modern technology, both in hardware and software front have brought potential to provide intelligent navigation capabilities. Recently there has been a lot of Electronic Travel Aids (ETA) designed and devised to help the blind navigate independently and safely. Also high-end technological solutions have been introduced recently to help blind persons to navigate independently. Many blind guidance systems use ultrasound because of its immunity to the environmental noise. Another reason why ultrasonic is popular is that the technology is relatively inexpensive, and also ultrasound emitters and detectors are small enough to be carried without the need for complex circuit. Blind people have used canes as mobility tools for centuries, but it was not until after World War I that the white cane was introduced.

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1.2 LITERATURE SURVEY Numerous attempts have been made in the society to help the blind. “Project Prakash” is a humanitarian mission to help the blind children especially by training them to utilize their brains to learn a set of objects around them. The stick has a ping sonar sensor to sense the distant objects. It also has a wet detector to detect the water. The micro-controller used is PIC microcontroller. The microcontroller circuit is on the outside of the stick but is protected with a code so its security cannot be breached. The only feedback given to the user is through the vibration motor. Three sensors are used viz. ultrasonic, pit sensor and the water sensor. Even this is a PIC based system. The feedback given is through the vibration as well as the speaker/headphones. There is a GPS system where-in the user has to feed his location. No information on how a blind man would do that. Also they haven’t mentioned anything about the size and shape of their cane and neither about the placement of their circuitry. The author has made a detachable unit consisting of an ultrasonic sensor and a vibration motor. It can be fit on any stick. It detects obstacles up to 3cm. The vibration feedback varies in the intensity as the obstacles come nearer. Many different approaches have been taken with the primary purpose of creating a technology to aid the visually impaired. The priorities set by different authors are different leaving a scope of improvement in every application.

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1.3 Project Outline :-

In this system the ultrasonic sensor are used to sense the obstacle (if there is any). The signal is then send to microcontroller to operate a buzzer and a vibrating Motor.The project is basically implementing the detection of front object for handicraft person through VIBRATING MOTOR & ALARM BEEP which is indirectly applied by power device. The silent features of project are :-

1. The HPM will detect the obstacle and warn the user. 2. Diffrent Type of sound for Diffrent Distance. 3. Depth and Height of any Obstacle can Be Detected. 4. Vibration Motor help the user in crowdy Envirenment. 5. Portable and easy to use.

Figure 1.1 Block Diagram of Project

Microcontroller

Ultrasonic Sensor

Buzzer Vibrating Motor

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1.4 Objective : The learning objectives for this project are:

An introduction of ARDIUNO IDE 1.6.6 and its coding part. An introduction to SR-04 ultrasonic range finder and its operation. Basic operation of Atmega328P-PU. Study of Vibrating Motor. Use of bread boards and PCB for analysis. Basic concepts of PCB design, and experience developing a simple PCB Layer. Experience soldering together a circuit and constructing a semi-professional project

box for it. Experience of using Fritzing Software to stables connection between component. Developing debugging skills.

1.5 Parts Required: Following is the list of parts or the components required to design this circuit:- 1. Atmega328P-PU 2. HC Sr-04 ultrasonic Sensor 3. Buzzer 4. Vibrating Motor 5. 7805 Voltage Regulator 6. 10uf capacitor 7. 16mhz Crystal capacitor 8. 22pf Disk Capacitor 9. Resistor (10kohm) 10. Zero PCB board 11. Header Pins 12. 28 pin IC socket 13. Connecting Wires 14. Switch 15. Battery (9V) 16. LED 17. Fritzing Software 18. ARDUINO IDE 1.6.6 19. Soldering Iron, Soldering Wire 20. PCB Designing Material

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1.6 CONTRUCTION:

STEPS TO BUILD CIRCUIT

a. A printed circuit board (PCB) is designed for the circuit diagram and required component are made available.

b. The value of each resister identified by reading the color bands painted on its body.

c. Capacitors are also identified by the method of identification. d. The pin detail of transmission, chips and ultrasounds are known by referring

to their data sheets. SOLDERING

a. Assemble all the components of the circuit on PCB as per the circuit diagram. b. Start from the left most corner of the PCB and solder one by one on their

correct position on PCB.

COMPLETE PROCEDURE The complete procedure can be summarized as:

a. Design the Circuit using Fritzing Software. b. Burn Bootloader and Program the Atmega328P-Pu using Arduino IDE 1.6.6

software from computer. c. After successfully programming the Microcontroller, take the Microcontroller out

from the programmer and connect base on the PCB of the circuit. d. After assembling and soldering all other components, connect external power

supply. e. Check the input and output power at the pins IN, OUT at both the circuits of

Project. f. After successfully checking of the circuit mount the other required

components on their required places at PCB circuits.

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Chapter-2 ULTRASONIC SENSOR

2.1 Introduction Ultrasonic technology was for over 40 years employed in the steel industry, initially with flaw detection and later joined by wall thickness measurement. For the past 15 years the plastics industry has used ultrasonic testing in the field of wall thickness measurement of pipe extrusions. Quality considerations and material savings serve as arguments for investment in and protection against the increasingly important aspect of product liability. Also, Automation increasingly is being used in order to facilitate the use of data to recalculate the production costs of individual products and optimize the entire plant from this. Material Saving Automation Quality Control

In the last few years, considerable efforts were made to utilize ultrasonic wall thickness measuring systems in the pipe extrusion. This ultimately was demonstrated by a multitude of key patents. Acoustic frequencies between 16 kHz and 1 GHz are referred to as ultrasound; in industrial settings we call it “ultrasonic”. To clarify: people are able to hear frequencies between 16 Hz and 20 kHz; i.e. the lower frequencies of industrial ultrasonic are audible, especially if secondary frequencies are generated. And what is more, ultrasonic is palpable when touching the weld tool. For ultrasonic welding, the frequency range is between 20 kHz and 70 kHz. Additional fields of application: Imaging ultrasound in the field of medical diagnostics ranges between 1 and 40 MHz It is not audible or palpable. In the field of industrial material testing, ultrasonic is used at frequencies from 0.25 to 10 MHz . This project, an ultrasonic rangefinder from 1979, shows how to make a distance finding device using ultrasonic sound waves. This includes only the block diagrams and no circuit but detailed description shows what is going on. The interesting part of this design is not so much the range finder itself (since using microcontrollers you can build one more easily), rather it is using a simple RC circuit to differentiate a mono stable pulse output (a square pulse). And then using a comparator to trigger activation of the receiver. Not only this but the received ultrasonic signal is used as input

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to the other side of the comparator as a reference i.e. to trigger the measurement action. The key point is that the differentiated pulse lowers the threshold for the comparator trigger meaning that the circuit should respond better to lower signal levels i.e. reflected ultrasonic sounds received from a greater distance. There is a free project on this site for a microcontroller based ultrasonic range finder with circuit diagrams - it would be interesting to add in the variable threshold and see if it can be improved! it should do so as the level detected will be improved the further the distance that the ultrasonic sound wave is reflected. For changes in that circuit (in the above link): You can see the threshold comparator U6 and threshold adjust VR2. You would need to use a spare output from the 16F88 say one of the spare signals on port RB, to generate a pulse and then add the CR network to differentiate that and feed into the comparator (pin 3). 2.2 Description of the Ultrasonic Sensor The present design provides an ultrasonic rangefinder comprising a first transducer for transducing electric signals into ultrasonic waves and transmitting said ultrasonic waves, a second transducer for receiving said ultrasonic waves and transducing said ultrasonic waves into electric signals, a first timer means for determining a starting time for transmitting said ultrasonic waves, a carrier frequency generator for generating a carrier signal of a frequency of said ultrasonic waves, a second timer means for generating a pulse having a time width at least longer than a time corresponding to a travelling time of said ultrasonic waves from said first transducer to said second transducer at the time when said first transducer begins to transmit said ultrasonic waves, a differentiation circuit for differentiating said pulse of said second timer means, and a comparator for comparing a level of said differentiated output signal from said differentiation circuit with an output signal level of said second transducer and detecting a threshold time when said level of said differentiated output signal from said differentiation circuit becomes lower than said output signal level of said second transducer.

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Figure 2.1 : Is a block diagram of an ultrasonic rangefinder in accordance with the present invention for the ultrasonic rangefinder

Figure 2.2 : Is a timing chart showing signals designated by curves (a)-(h) of the outputs of several blocks shown in fig. 1 for the ultrasonic rangefinder The preferred embodiment of the present design is elucidated by referring to the accompanying drawings. FIG. 1 is a block diagram of an ultrasonic rangefinder in accordance with the present design. FIG. 2 is a timing chart showing signals designated by curves (a)-(h) in several blocks of

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FIG. 2.1. A pulse generating circuit (PGC) 1 of FIG. 2.1 generates one start pulse P1 shown by the curve (a) of FIG. 2.2 every time a switch SW is turned on. A first mono stable multivibrator (MMV) 2 serves as a first timer means, is triggered by the start pulse P1, and generates an output signal which has a high logic level part PA for a time period of t2 as shown by the curve (b) of FIG. 2.2 A carrier frequency generator (CFG) 3 continuously generates a signal of a carrier wave frequency used for the ultrasonic range finding. An AND gate circuit 4 passes the continuously generated signal for the time period t2 and gives a burst signal A shown in the curve (c) of FIG. 2. Therefore, the burst signal A lasts only during the time period t2 when the output signal of the mono stable multivibrator (MMV) 2 is at the high logic level. A power amplifier 5 amplifies the burst signal A of an ultrasonic frequency, thereby driving a transducer such as a speaker 6 for producing the ultrasonic waves.An ultrasonic wave is reflected by an object 13 and reaches a microphone 8 which converts the ultrasonic wave into an electric signal. An amplifier 7 amplifies the electric signal sent out from the microphone 8. A center frequency of the amplifier 7 is set to be the ultrasonic frequency of the burst signal A, namely the carrier frequency generator (CFG) 3, so that the reflected ultrasonic signal only is amplified thereby. A second mono stable multivibrator (MMV) 9 serves as a second timer means, is triggered by the abovementioned start pulse P1, and generates an output signal PB having a high logic level for a time period t9 as shown by the curve (d) of FIG. 2.2 A differentiation circuit 10 having a relatively long predetermined time constant differentiates the output signal of the second mono stable multivibrator (MMV) 9.

Figure 2.3 : Is a circuit diagram of a typical differentiation circuit together with input and output signal waveforms for the ultrasonic rangefinder FIG. 3 is a circuit diagram showing a typical differential circuit together with input and output signal waveforms. The differentiation circuit 10 generates a signal V1 changing its waveform exponentially as shown by the curve (e) of FIG. 2. An analog comparator 11 compares the voltage of the signal V1 of the differentiation circuit 10 with that of an output signal V2 of the amplifier 7, and inverts a logic level of an output signal to a high logic level when the voltage of the signal V1 is lower than that of the signal V2. A flip-flop (FF) 12 has been previously set by the abovementioned start pulse P1 thereby holding its output signal shown by the curve (h) of FIG. 2 at a high logic

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level until the output signal of the analog comparator 11 is inverted to the high logic level. When the switch SW is turned on, the ultrasonic waves are generated from the speaker 6 during the time period t2. They reach the object 13 and are reflected from the object 13. Then, the microphone 8 detects the reflected ultrasonic waves thereby generating an electric signal, which is then selectively amplified by the amplifier 7. The output signal V2 of the amplifier 7 is an analog signal F2 shown by the curve (f) of FIG. 2. The output signal V1 of the differentiation circuit 10 is expressed by using the input signal thereof, i.e. an output signal E of the second mono stable multivibrator (MMV) 9 as, where C and R are a capacitance and a resistor of the differentiation circuit 10, respectively, and t is the time. The equation (1) can be approximately expanded to result in

The level of the signal V2 in proportion to the received ultrasonic waves also decays as the time passes. Therefore, it is necessary that the sensitivity of the analog comparator (COM) 11 complies with a distance from the rangefinder to the object 13 (in other words, with the time required for the ultrasonic waves to be reflected from the object 13 and to return to the rangefinder). For this purpose, the output signal of the flip-flop (FF) 12 is turned to a low logic level when the signal V2 by the received ultrasonic waves becomes higher than the output signal V1 of the differentiation circuit 10 after a predetermined time t12 from the time when the flip-flop (FF) 12 is set by the start pulse P1. An indication means 14 is used to display a time period during which the logic level of the flip-flop 12 is at the high logic level. Suitable indicating means are known to those in this art and could, for example, be a counter. It is a known technique to display a value responding to a distance by selecting a clock pulse frequency used for the counting. The sound wave propagation velocity v (m/sec) in the air is expressed by where T is the temperature in centigrade. A distance L(m) from the rangefinder to the object 13 can be calculated by

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Figure 2.4 : Is a graph showing waveforms of ultrasonic wave signals versus time for the ultrasonic rangefinder where t12 is the time corresponding to the time from the sending to the receiving of the ultrasonic waves. The relationship between the sound strength of the received ultrasonic waves and the distance L is that the former is inversely proportional to the latter. Therefore, when an ultrasonic wave pulse shown by a curve (c') of FIG. 4 is used for the rangefinding of three different objects O1, O2 and O3 positioned at different places distant from the rangefinder, the sound strength of the received ultrasonic waves decreases in accordance with the distances of the objects from the rangefinder as shown by a curve (f') of FIG. 4, even when the reflection coefficients of the objects are equal to each other. The rangefinder in accordance with the present design uses the output signal V1 of the differentiation circuit 10 as a threshold value of the analog comparator (COM) 11. The output signal V1 is time-dependent as described above, and therefore the rangefinder in accordance with the present design is devised in such a manner that the threshold value used for the comparison in the analog comparator (COM) 11 is automatically varied in accordance with the time required for the ultrasonic waves to reach the rangefinder after the reflection. When the direct waves are received by the microphone 8 immediately after the ultrasonic waves are transmitted from the speaker 6 and before the reflection waves are received by the microphone 8, the amplifier 7 produces a spurious output signal F1 in the curve (f) of FIG. 2. At this time, the signal V1 is higher than the spurious output signal F1 so that the comparator 11 does not generate the inverted high level signal. Accordingly, it is possible to remove effects of undesirable spurious electric signals induced by the direct ultrasonic waves. It is thus possible to correctly carry out the rangefinding even for the object positioned at an extremely proximate place from the rangefinder. It is naturally that the speaker 6 for producing the ultrasonic waves and the microphone 8 for receiving the ultrasonic waves are transducers designed for the ultrasonic wave range having the most preferable electric-mechanical and mechanic-electrical conversion efficiency values in the

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ultrasonic frequency range controlled by the carrier frequency generator (CFG) 3. In the timing chart of FIG. 2 analog signal parts are enlarged in the time axis. When the oscillation frequency of the carrier frequency generator (CFG) 3 is set to be 40 KHz, the predetermined time period t2 of the first mono stable multivibrator (MMV) 2 be 2 m sec and the maximum setting distance value be 3.4 m, then the predetermined time period t9 of the second monostable multivibrator (MMV) 9 becomes 20 m sec. It is possible that the ultrasonic rangefinder in accordance with the present design further comprises a display means (not shown in FIG. 1) to indicate that the ultrasonic rangefinder is unable to measure the object distance when the output signal (h) of the flip-flop (FF) 12 does not invert the output signed within the predetermined time period t9 of the second mono stable multivibrator (MMV) 9 (i.e. the reflection waves are not obtained within the predetermined time period t9). It is further possible to provide a counter means in the ultrasonic rangefinder of the present design by using a suitable clock signal and the output signal (h) of the flip-flop (FF) 12 as a gate signal.

Figure 2.5 : Is a circuit diagram of a known simple oscillator circuit for the ultrasonic rangefinder

FIG. 5 is a circuit diagram showing a known simple oscillation circuit comprising a capacitor C', a resistor R' and an inverter 14. Such an oscillation circuit is applicable to the first and second monostable multivibrators 2 and 9. An oscillation frequency of the oscillation circuit is variable by selecting a suitable time constant of the capacitor C' and the resistor R'. It is therefore possible to remove a temperature-dependent effect of the sound velocity from the measured distance value by using a temperature-sensitive device such as a thermistor instead of the resistor R' in such a manner that the frequency dependence of the clock signal on the temperature coincides with the sound velocity dependence on the temperature expressed by the equation (3). It is still further possible to employ the oscillation circuit of FIG. 5 as the carrier frequency generator (CFG) 3 when the temperature compensation is made therein, since the frequency characteristics of the speaker 6 and the microphone 8 and the frequency characteristics of the amplifier 7 are not affected within the variable range of the sound velocity expressed by the equation (3). When the

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oscillation frequency of the carrier frequency generator 3 is set to be around 34 KHz, the distance corresponding to one cycle of the ultrasonic waves is 1 cm (assuming the temperature is around 10° C.). Thus a direct indication in centimeter unit is possible by using a signal as a counter clock signal for the time period t12 after dividing the signal of the carrier frequency generator (CFG) 3 to get the signal of the frequency of a half of the oscillation frequency. It is preferable that the time period t2 of the first monostable multivibrator (MMV) 2 for determining a pulse width of the transmitting ultrasonic waves is set to be a value equal to or slightly longer than response times of the speaker 6 and microphone 8, which response times are given by the mechanical Q values thereof. The ultrasonic rangefinder of the present design provides a possibility of a correct distance measurement with a simple circuit constitution where the threshold signal level of the analog comparator 11 to the reflection waves is automatically varied with respect to the time lapse of the travelling of the ultrasonic waves thus overcoming the conventional problems due to the direct waves. 2.3 Executive Summary of the Ultrasonic Rangefinder An ultrasonic rangefinder providing a correct distance measurement and comprising a first transducer for transducing electric signals into ultrasonic waves and transmitting the ultrasonic waves, a second transducer for receiving the ultrasonic waves and transducing the ultrasonic waves into electric signals, a differentiation circuit, and a comparator for comparing a level of a differentiated output signal from the differentiation circuit with an output signal level of the second transducer and detecting a threshold time when the level of the differentiated output signal from the differentiation circuit becomes lower then the output signal level of the second transducer where a threshold signal level of the comparator is automatically varied with respect to a time lapse of the travelling ultrasonic waves coming back to the rangefinder after being reflected by an object, thus overcoming the conventional problems due to the spurious-like direct waves. 2.4 Ultrasonic Ranging Module HC - SR04 Ultrasonic Ranging Module HC - SR04 Product features: Ultrasonic ranging module HC - SR04 provides 2cm - 400cm non-contact measurement function, the ranging accuracy can reach to 3mm. The modules includes ultrasonic transmitters, receiver and control circuit. The basic principle of work: (1) Using IO trigger for at least 10us high level signal, (2) The Module automatically sends eight 40 kHz and detect whether there is a pulse signal back. (3) IF the signal back, through high level , time of high output IO duration is the time from sending ultrasonic to returning.

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Test distance = (high level time×velocity of sound (340M/S) / 2, Wire connecting direct as following: _ 5V Supply _ Trigger Pulse Input _ Echo Pulse Output _ 0V Ground Electric Parameter Working Voltage DC 5 V,Working Current 15mA,Working Frequency 40Hz,Max Range 4m,Min Range 2cm,MeasuringAngle 15 degree,Trigger Input Signal 10uS TTL pulse,Echo Output Signal Input TTL lever signal and the range in

Figure 2.6 Ultrasonic Ranging Module HC - SR04 Timing diagram The Timing diagram is shown below. You only need to supply a short 10uS pulse to the trigger input to start the ranging, and then the module will send out an 8 cycle burst of ultrasound at 40 kHz and raise its echo. The Echo is a distance object that is pulse width and the range in proportion .You can calculate the range through the time interval between sending trigger signal and receiving echo signal. Formula: uS / 58 = centimeters or uS / 148 =inch; or: the range = high level time * velocity (340M/S) / 2; we suggest to use over 60ms measurement cycle, in order to prevent trigger signal to the echo signal.

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Chapter-3

ATmega328P-PU 3.1 Introduction The high-performance Atmel picoPower 8-bit AVR RISC-based microcontroller combines 32KB ISP flash memory with read-while-write capabilities, 1024B EEPROM, 2KB SRAM, 23 general purpose I/O lines, 32 general purpose working registers, three flexible timer/counters with compare modes, internal and external interrupts, serial programmable USART, a byte-oriented 2-wire serial interface, SPI serial port, a 6-channel 10-bit A/D converter (8-channels in TQFP and QFN/MLF packages), programmable watchdog timer with internal oscillator, and five software selectable power saving modes. The device operates between 1.8-5.5 volts. By executing powerful instructions in a single clock cycle, the device achieves throughputs approaching 1 MIPS per MHz, balancing power consumption and processing speed. 3.2Key parameters

Parameter Value

CPU type 8-bit AVR

Performance 20 MIPS at 20 MHz

Flash memory 32 kB

SRAM 2 kB

EEPROM 1 kB

Pin count 28-pin PDIP, MLF, 32-pin TQFP, MLF

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Maximum operating frequency 20 MHz

Number of touch channels 16

Hardware QTouch Acquisition No

Maximum I/O pins 26

External interrupts 24

USB Interface No

USB Speed No

Table: 1 3.3 Series alternatives A common alternative to the ATmega328 is the "picoPower" ATmega328P. A comprehensive list of all other member of the megaAVR series can be found on the Atmel website. 3.4 Applications As of 2013 the ATmega328 is commonly used in many projects and autonomous systems where a simple, low-powered, low-cost micro-controller is needed. Perhaps the most common implementation of this chip is on the popular Arduino development platform, namely the Arduino Uno and Arduino Nano models. 3.5 Programming

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Figure:3.1 Pinout of ATmega 48A/PA/88A/PA/168A/PA/328/P in 28-PDIP (datasheet)

Reliability qualification shows that the projected data retention failure rate is much less than 1 PPM over 20 years at 85 °C or 100 years at 25 °C.

Parallel program mode

Programming signal Pin Name I/O Function

RDY/BSY PD1 O High means the MCU is ready for a new command, otherwise busy.

OE PD2 I Output Enable (Active low)

WR PD3 I Write Pulse (Active low)

BS1 PD4 I Byte Select 1 (“0” = Low byte, “1” = High byte)

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XA0 PD5 I XTAL Action bit 0

XA1 PD6 I XTAL Action bit 1

PAGEL PD7 I Program memory and EEPROM Data Page Load

BS2 PC2 I Byte Select 2 (“0” = Low byte, “1” = 2nd High byte)

DATA PC[1:0]:PB[5:0] I/O Bi-directional data bus (Output when OE is low) Table: 2

Programming mode is entered when PAGEL (PD7), XA1 (PD6), XA0 (PD5), BS1 (PD4) is set to zero. RESET pin to 0V and VCC to 0V. VCC is set to 4.5 - 5.5V. Wait 60 μs, and RESET is set to 11.5 - 12.5 V. Wait more than 310 μs. Set XA1:XA0:BS1:DATA = 100 1000 0000, pulse XTAL1 for at least 150 ns, pulse WR to zero. This starts the Chip Erase. Wait until RDY/BSY (PD1) goes high. XA1:XA0:BS1:DATA = 100 0001 0000, XTAL1 pulse, pulse WR to zero. This is the Flash write command. And so on.

Serial Programming[2]

Symbol Pins I/O Description

MOSI PB3 I Serial data in

MISO PB4 O Serial Data out

SCK PB5 I Serial Clock

Table 3

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Serial data to the MCU is clocked on the rising edge and data from the MCU is clocked on the falling edge. Power is applied to VCC while RESET and SCK are set to zero. Wait for at least 20 ms and then the Programming Enable serial instruction 0xAC, 0x53, 0x00, 0x00 is sent to the MOSI pin. The second byte (0x53) will be echoed back by the MCU.

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Chapter-4 7805 VOLTAGE REGULATOR

4.1 Introduction A regulated power supply is very much essential for several electronic devices due to the semiconductor material employed in them have a fixed rate of current as well as voltage. The device may get damaged if there is any deviation from the fixed rate. The AC power supply gets converted into constant DC by this circuit. By the help of a voltage regulator DC, unregulated output will be fixed to a constant voltage. The circuit is made up of linear voltage regulator 7805 along with capacitors and resistors with bridge rectifier made up from diodes. From giving an unchanging voltage supply to building confident that output reaches uninterrupted to the appliance, the diodes along with capacitors handle elevated efficient signal conveyal. 4.2 Description: As we have previously talked about that regulated power supply is a device that mechanized on DC voltages and also it can uphold its output accurately at a fixed voltage all the time although if there is a significant alteration in the DC input voltage. ICs regulator is mainly used in the circuit to maintain the exact voltage which is followed by the power supply. A regulator is mainly employed with the capacitor connected in parallel to the input terminal and the output terminal of the IC regulator. For the checking of gigantic alterations in the input as well as in the output filter, capacitors are used. While the bypass capacitors are used to check the small period spikes on the input and output level. Bypass capacitors are mainly of small values that are used to bypass the small period pulses straightly into the Earth.A circuit diagram having regulator IC and all the above discussed components arrangement revealed in the figure below.

Fig.4.1Regulated Power Supply Circuit

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The working of the components coupled in the circuit above is revealed in the following table: COMPONEN

T FUNCTION

C1 This capacitor is known as bypass capacitor and is employed to bypass extremely tiny duration spikes to the ground with no distress the other components.

C2 C2 is the filter capacitor employed to steady the slow changes in the voltage applied at the input of the circuit. Escalating the value of the capacitor amplify the stabilization as well as the declining value of the capacitor reduces the stabilization. More over this capacitor is not alone capable to ensure very constricted period spikes emerge at the input.

C3 C3 is known as a filter capacitor employed in the circuit to steady the slow alterations in the output voltage. Raising the value of the capacitor enlarges the stabilization furthermore declining the value of the capacitor declined the stabilization. Moreover this capacitor is not alone capable to ensure very fine duration spikes happen at the output.

C4 C4 is known as bypass capacitor and worked to bypass very small period spikes to the earth with no influence the other components.

U1 U1 is the IC with positive DC and it upholds the output voltage steady exactly at a constant value even although there are major deviation in the input voltage.

Table 4

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As we have made the whole circuit till now to be operated on the 5V DC supply, so we have to use an IC regulator for 5V DC. And the most generally used IC regulators get into the market for 5V DC regulation use is 7805. So we are connecting the similar IC in the circuit as U1. IC 7805 is a DC regulated IC of 5V. This IC is very flexible and is widely employed in all types of circuit like a voltage regulator. It is a three terminal device and mainly called input , output and ground. Pin diagram of the IC 7805 is shown in the diagram below.

Figure 4.2 Pin Diagram of IC 7805

The pin explanation of the 7805 is described in the following table: PIN NO. PIN DESCRIPTION

1 INPUT In this pin of the IC positive unregulated voltage is given in regulation.

2 GROUND In this pin where the ground is given. This pin is neutral for equally the input and output.

3 OUTPUT The output of the regulated 5V volt is taken out at this pin of the IC regulator.

Table 5

In the circuit diagram C2 as well as C3 are filter capacitor while bypass capacitors are the C1 and C4.The electrolytic polarized capacitors are employed for this purpose. For the purpose of filter capacitors normally 10mfd value of the capacitor used. And in these projects we also used 100mfd value of the capacitor. While in all kinds of circuit the value of bypass capacitor is 0.1 mfd. And in generally un-polarized mainly disc capacitors employed for this purpose.

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Currently we have the circuit for the 5V DC positive regulation and we are also familiar with the component values used in the circuit. In the table below we have mentioned the value in detail of all the components used in the circuit of 5V DC positive regulator.

SNO COMPONENT TYPE VALUE

1 C1 CAPACITOR 0.1 mfd

2 C2 CAPACITOR 1000 mfd

3 C3 CAPACITOR 1000 mfd

4 C4 CAPACITOR 0.1 mfd

5 U1 POSITIVE DC REGULATOR 7805 Table 6

4.3 Example of 7805 Regulator: How to Get Constant DC Power Supply from AC?

Figure 4.3 7805 Voltage Regulator Circuit Diagram

The output generated from the unregulated DC output is susceptible to the fluctuations of the input signal. IC voltage regulator is connected with bridge rectifier in series in these project so to steady

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the DC output against the variations in the input DC voltage. To obtain a stable output of 5V, IC 7805 is attached with 6-0-6V along with 500mA step down transformer as well as with rectifier. To suppress the oscillation which might generate in the regulator IC, C2 capacitor of 0.1 uF value is used. When the power supply filter is far away from the regulated IC capacitor C2 is used. Ripple rejection in the regulator is been improved by C4 capacitor (35uf) by avoiding the ripple voltage to be amplified at the regulator output. The output voltage is strengthen and deduction of the output voltage is done capacitor C3 (0.1uF). To avoid the chance of the input get shorted D5 diode is used to save the regulator. If D5 is not presented in the circuit, the output capacitor can leave its charge immediately during low impedance course inside the regulator.

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Chapter-5 VIBRATING MOTOR

5.1 Introduction There are two basic types of vibration motor. An eccentric rotating mass vibration motor (ERM) uses a small unbalanced mass on a DC motor, when it rotates it creates a force that translates to vibrations. A linear resonant actuator (LRA) contains a small internal mass attached to a spring, which creates a force when driven. As specialists in the supply and design of vibration motors, you can find our stocked motors in our product catalogue. If you can't find exactly what you need, or would like to discuss a project, please do not hesitate to contact our engineers here. If you prefer to read online, you will find lots of additional information and guides to help you understand how vibration motors work. See the sections below to explore our different vibration motors!

Figure 5.1 : Brushless Dura Vibe™ Vibration Motor

5.2 An Introduction of Vibration Motors Small vibration motors have been around since the 1960s. Initially they were developed for massaging products, but their development took a new turn in the 90's when consumers required

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vibra-call on their mobile / cell phones. Today, designers and users alike have learned from two decades of mobile phones, that vibration alerting is an excellent way to alert operators to an event. These days miniature vibrating motors are used in a wide range of products, such as tools, scanners, medical instruments, GPS trackers, and control sticks. Vibrator motors are also the main actuators for haptic feedback which is an inexpensive way to increase a product's value, and differentiate it from competition. So, if you landed here because you want to make something vibrate, you're in good company. Precision Microdrives is the leading supplier of sub Ø60 mm vibrating motors. We carry the widest range of stock and we offer unrivaled application support and on-hand technical expertise. 5.3 Precision Microdrives Vibration Motor Ranges Our ranges of vibration motors help group together alternative products for similar applications, mainly by their construction. You can click on the images below to read more about each range and access the different vibration motors' datasheets. Our Pico Vibe™ Range includes our smallest DC vibration motors, perfect for lightweight applications or where space is at a premium. They include miniaturised DC coreless motors with eccentric masses, both in cylindrical and coin form (see the Form Factors section below for more details). This is our widest range, from lightweight vibrations in sizes down to 3mm up to powerful 6G+ motors, they will fit a variety of different applications and power needs. Precision Haptic™ actuators include our linear resonant actuators as well as a few eccentric rotating mass vibration motors that are specifically design for haptic feedback applications. They have excellent rise and stop times, which can be improved using specialised driving techniques. You may also wish to compare them to our Pico Vibe™ range as, although not singled out, many of them also offer great haptic performance. Why not try our Haptic Feedback Evaluation Kit to compare different actuators?

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Our largest motors are found in our Uni Vibe™ range, which are often our most powerful due to their bigger size. However, as specialists in the supply of miniature DC vibration motors, these ERMs typically do not exceed 50mm in diameter. With the extra vibration strength, our Uni Vibe™ motors are perfect for heavier applications or for those seeking extra vibration strength. Our brushless vibration motors are in our Dura Vibe™ range. They are long-life motors that are suitable for applications that demand extra long performance time. To achieve this they are based on BLDC motors so do not suffer from commutator wear. Many of these BLDC vibration motors are coin types that include an internal driving IC, making them very easy to integrate.

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5.4 Different Vibration Motor Form Factors Whilst the end goal of vibration motors is to produce a force, there are many ways of achieving it. There is a wide range of physical forms, both internal and external, to help you achieve this. To guide you, the articles below help describe the main characteristics of each type. You will notice that some motors may belong to multiple categories, for example our encapsulated motors are based on ERMs, so you may want to look at several different types for additional information. Our most popular form factor is the ERM or 'pager' motor. This is because there are lots of DC motors available in this cylindrical form, where the eccentric mass helps create an unbalanced force. They are also the most versatile - they can be mounted on PCBs, encapsulated, use a variety of power connections, and even be based on brushless motors. However, coin or 'pancake' motors use the same operating principle - but their eccentric mass is kept in their small circular body (which is where they get their names from). They are restricted in amplitude because of their size, but have extremely low profiles (only a few mm!) which make them popular in applications which space is restricted.

Encapsulation is the process of sealing an ERM into a plastic housing. These units are popular for applications where the motor is housed with injection moulding or ones that require waterproof vibration motors. Motors that are mounted to PCBs have several connection types, including SMD vibration motors, through-hole chassis, or spring pad terminals. Some even use leaded power connections and a specialized mounting technique (like adhesives) so that PCB tracks do not need to reach the motor itself.

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Linear Resonant Actuators (LRA) are the most unique devices in our collection of vibration motors. Although they sometimes look like coin motors, they do not use an eccentric mass to create force. Instead, they have a magnetic mass attached to a spring and driven by a voice coil - a similar design to loudspeakers. This means they are very efficient, have excellent response, and need different drivers compared to a DC vibration motor. Similarly, brushless vibration motors also have different driving requirements. Without wearing the brushes of the commutator, they last for a very long time but (unless the vibration motor has an internal driver IC) are slightly more complicated to operate.

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5.5 Common Vibration Motor Applications And Examples Our customers are always coming up with ever more inventive uses for vibration motors, so it is difficult for us to list them all here! To help, we have discussed some of our most popular categories over the years below. Haptic Feedback and Vibration Alerting are not necessarily applications themselves, but they are different methods of implementing vibrations within applications. Haptic Feedback uses advanced vibration patterns and effects to convey complicated information to users. Vibration Alerting tends to be a simple on / off alert, perhaps with a ramp effect. A good example is a mobile phone, which in the early days would simply vibrate to notify the user of a call / text. Later, they would play SMS in morse code, now they have a range of effects for games and applications. Over time, they have progressed from Vibration Alerting to Haptic Feedback.

Vibration motors are a popular method for moving materials and produce that can become stuck in chutes or hoppers without the need for human intervention. These applications typically employ some of our larger motors, however emulsifiers or scientific experiments sometimes make use of smaller vibration motors that meet their specific requirements. Conversly, medical applications will often use the smaller devices as within handheld equipment. These devices often have tight requirements for their suppliers, including factory audits, which we are more than happy to help with at Precision Microdrives.

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Light, portable devices that need to alert users are perfect for miniature vibration motors - especially when they are powered by batteries. Our wide range of stocked motors helps you select a vibration motor that fits your device's form factor - not the other way around. Cars are using more and more sensors to assist drivers, unfortunately these are accompanied with annoying beeps and tones. Vibration motors help give silent information to the driver, or augment the audio only warnings.

5.6 Operation: ELECTRO FLUX Vibratory Motor is specially designed Energy efficiency Motor, having Un balanced weight at both end of the shaft. Rotation of Un balanced weight at shaft end causes vibration.

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By changing their lead angle, various screening patterns are obtained to suit different application. Flange mounting and foot mounting Motors are available in various ranges.

Figure 5.3 Vibrating Motor

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Chapter-6 CAPACITOR & RESISTOR

6.1 Introduction of Capacitor A capacitor is a passive two-terminal electrical component that stores electrical energy in an electric field. The effect of a capacitor is known as capacitance. While capacitance exists between any two electrical conductors of a circuit in sufficiently close proximity, a capacitor is specifically designed to provide and enhance this effect for a variety of practical applications by consideration of size, shape, and positioning of closely spaced conductors, and the intervening dielectric material. A capacitor was there for historically first known as an electric condenser. The physical form and construction of practical capacitors vary widely and many capacitor types are in common use. Most capacitors contain at least two electrical conductors often in the form of metallic plates or surfaces separated by a dielectric medium. The conductors may be foils, thin films, or sintered beads of metal or conductive electrolyte. The nonconducting dielectric acts to increase the capacitor's charge capacity. Materials commonly used as dielectrics include glass, ceramic, plastic film, paper, mica, and oxide layers. Capacitors are widely used as parts of electrical circuits in many common electrical devices. Unlike a resistor, an ideal capacitor does not dissipate energy. When two conductors experience a potential difference, for example, when a capacitor is attached across a battery, an electric field develops across the dielectric, causing a net positive charge to collect on one plate and net negative charge to collect on the other plate. No current actually flows through the dielectric instead, the effect is a displacement of charges through the source circuit. If the condition is maintained sufficiently long, this displacement current through the battery seizes. However, if a time-varying voltage is applied across the leads of the capacitor, the source experiences an ongoing current due to the charging and discharging cycles of the capacitor. Capacitance is defined as the ratio of the electric charge Q on each conductor to the potential difference V between them. The unit of capacitance in the International System of Units (SI) is the farad (F), which is equal to one coulomb per volt (1 C/V). Capacitance values of typical capacitors for use in general electronics range from about 1 pF (10−12 F) to about 1 mF (10−3 F). 6.2 Operation: A capacitor consists of two conductors separated by a non-conductive region. The non-conductive region can either be a vacuum or an electrical insulator material known as a dielectric. Examples of dielectric media are glass, air, paper, and even a semiconductor depletion region chemically

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identical to the conductors. A capacitor is assumed to be self-contained and isolated, with no net electric charge and no influence from any external electric field. The conductors thus hold equal and opposite charges on their facing surfaces, and the dielectric develops an electric field. In SI units, a capacitance of one farad means that one coulomb of charge on each conductor causes a voltage of one volt across the device. An ideal capacitor is wholly characterized by a constant capacitance C, defined as the ratio of charge ±Q on each conductor to the voltage V between them:

Figure 6.1 Capacitor-Plate Separation Because the conductors (or plates) are close together, the opposite charges on the conductors attract one another due to their electric fields, allowing the capacitor to store more charge for a given voltage than if the conductors were separated, giving the capacitor a large capacitance. Sometimes charge build-up affects the capacitor mechanically, causing its capacitance to vary. In this case, capacitance is defined in terms of incremental changes:

6.3 Networks

For capacitors in parallel Capacitors in a parallel configuration each have the same applied voltage. Their capacitances add up. Charge is apportioned among them by size. Using the schematic diagram to visualize parallel plates, it is apparent that each capacitor contributes to the total surface area.

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Several capacitors in parallel For capacitors in series

Several capacitors in series Figure 6.2 Capacitor Series and parallel

Connected in series, the schematic diagram reveals that the separation distance, not the plate area, adds up. The capacitors each store instantaneous charge build-up equal to that of every other capacitor in the series. The total voltage difference from end to end is apportioned to each capacitor according to the inverse of its capacitance. The entire series acts as a capacitor smaller than any of its components.

Capacitors are combined in series to achieve a higher working voltage, for example for smoothing a high voltage power supply. The voltage ratings, which are based on plate separation, add up, if capacitance and leakage currents for each capacitor are identical. In such an application, on occasion, series strings are connected in parallel, forming a matrix. The goal is to maximize the energy storage of the network without overloading any capacitor. For high-energy storage with capacitors in series, some safety considerations must be applied to ensure one capacitor failing and leaking current does not apply too much voltage to the other series capacitors.

6.4 Introduction of Resistor A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses. High-power resistors that can dissipate many watts of electrical power as heat may be used as part of motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have

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resistances that only change slightly with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements (such as a volume control or a lamp dimmer), or as sensing devices for heat, light, humidity, force, or chemical activity. Resistors are common elements of electrical networks and electronic circuits and are ubiquitous in electronic equipment. Practical resistors as discrete components can be composed of various compounds and forms. Resistors are also implemented within integrated circuits. The electrical function of a resistor is specified by its resistance: common commercial resistors are manufactured over a range of more than nine orders of magnitude. The nominal value of the resistance falls within the manufacturing tolerance, indicated on the component.

Figure 6.3 Resistor

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6.5 Operation

Figure 6.4 Concept The hydraulic analogy compares electric current flowing through circuits to water flowing through pipes. When a pipe (left) is clogged with hair (right), it takes a larger pressure to achieve the same flow of water. Pushing electric current through a large resistance is like pushing water through a pipe clogged with hair: It requires a larger push (voltage) to drive the same flow (electric current). 6.6 Ohm's law The behavior of an ideal resistor is dictated by the relationship specified by Ohm's law: Ohm's law states that the voltage (V) across a resistor is proportional to the current (I),

where the constant of proportionality is the resistance (R). For example, if a 300 ohm resistor is attached across the terminals of a 12 volt battery, then a current of 12 / 300 = 0.04 amperes flows through that resistor.

Practical resistors also have some inductance and capacitance which affect the relation between voltage and current in alternating current circuits.

The ohm (symbol: Ω) is the SI unit of electrical resistance, named after Georg Simon Ohm. An ohm is equivalent to a volt per ampere. Since resistors are specified and manufactured

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over a very large range of values, the derived units of milliohm (1 mΩ = 10−3 Ω), kilohm (1 kΩ = 103 Ω), and megohm (1 MΩ = 106 Ω) are also in common usage.

6.7 Series and parallel resistors The total resistance of resistors connected in series is the sum of their individual resistance values.

The total resistance of resistors connected in parallel is the reciprocal of the sum of the reciprocals of the individual resistors.

Figure 6.5 Resistor Series and parallel

For example, a 10 ohm resistor connected in parallel with a 5 ohm resistor and a 15 ohm resistor produces 1/1/10 + 1/5 + 1/15 ohms of resistance, or 30/11 = 2.727 ohms. A resistor network that is a combination of parallel and series connections can be broken up into smaller parts that are either one or the other. Some complex networks of resistors cannot be resolved in this manner, requiring more sophisticated circuit analysis. Generally, the Y-Δ transform, or matrix methods can be used to solve such problems.

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6.8 Power dissipation At any instant, the power P (watts) consumed by a resistor of resistance R (ohms) is calculated as: where V (volts) is the voltage across the resistor and I (amps) is the current flowing through it. Using Ohm's law, the two other forms can be derived. This power is converted into heat which must be dissipated by the resistor's package before its temperature rises excessively. Resistors are rated according to their maximum power dissipation. Discrete resistors in solid-state electronic systems are typically rated as 1/10, 1/8, or 1/4 watt. They usually absorb much less than a watt of electrical power and require little attention to their power rating.

Figure 6.6An aluminum-housed power resistor rated for 50 W when heat-sinked Resistors required to dissipate substantial amounts of power, particularly used in power supplies, power conversion circuits, and power amplifiers, are generally referred to as power resistors; this designation is loosely applied to resistors with power ratings of 1 watt or greater. Power resistors are physically larger and may not use the preferred values, color codes, and external packages described below. If the average power dissipated by a resistor is more than its power rating, damage to the resistor may occur, permanently altering its resistance; this is distinct from the reversible change in resistance due to its temperature coefficient when it warms. Excessive power dissipation may raise the temperature of the resistor to a point where it can burn the circuit board or adjacent components, or even cause a fire. There are flameproof resistors that fail (open circuit) before they overheat dangerously. Since poor air circulation, high altitude, or high operating temperatures may occur, resistors may be specified with higher rated dissipation than is experienced in service. All resistors have a maximum voltage rating; this may limit the power dissipation for higher resistance values

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Chapter-7 PRINTED CIRCUIT BOARD

7.1 Introduction A printed circuit board (PCB) mechanically supports and electrically connects electronic components using conductive tracks, pads and other features etched from copper sheets laminated onto a non-conductive substrate. Components – capacitors, resistors or active devices – are generally soldered on the PCB. Advanced PCBs may contain components embedded in the substrate. PCBs can be single sided (one copper layer), double sided (two copper layers) or multi-layer (outer and inner layers). Conductors on different layers are connected with vias. Multi-layer PCBs allow for much higher component density. FR-4 glass epoxy is the primary insulating substrate. A basic building block of the PCB is an FR-4 panel with a thin layer of copper foil laminated to one or both sides. In multi-layer boards multiple layers of material are laminated together. Printed circuit boards are used in all but the simplest electronic products. Alternatives to PCBs include wire wrap and point-to-point construction. PCBs require the additional design effort to lay out the circuit, but manufacturing and assembly can be automated. Manufacturing circuits with PCBs is cheaper and faster than with other wiring methods as components are mounted and wired with one single part. A minimal PCB with a single component used for easier modeling is called breakout board.[1] When the board has no embedded components it is more correctly called a printed wiring board (PWB) or etched wiring board. However, the term printed wiring board has fallen into disuse. A PCB populated with electronic components is called a printed circuit assembly (PCA), printed circuit board assembly or PCB assembly (PCBA). The IPC preferred term for assembled boards is circuit card assembly (CCA), and for assembled backplanes it is backplane assemblies. The term PCB is used informally both for bare and assembled boards.

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Figure 7.1 PCB 7.2 Design

Figure 7.2 A board designed in 1967; the sweeping curves in the traces are evidence of freehand design using

adhesive tape Initially PCBs were designed manually by creating a photomask on a clear Mylar sheet, usually at two or four times the true size. Starting from the schematic diagram the component pin pads were

laid out on the mylar and then traces were routed to connect the pads. Rub-on dry transfers of common component footprints increased efficiency. Traces were made with self-adhesive tape. Pre-printed non-reproducing grids on the mylar assisted in layout. To fabricate the board, the

finished photomask was photolithographic ally reproduced onto a photoresist coating on the blank copper-clad boards.

7.3 Pcb Designing and Fabrication Process Modern PCBs are designed with dedicated layout software, generally in the following steps:

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1. Schematic capture through an electronic design automation (EDA) tool. 2. Card dimensions and template are decided based on required circuitry and case of the PCB. 3. The positions of the components and heat sinks are determined. 4. Layer stack of the PCB is decided, with one to tens of layers depending on

complexity. Ground and power planes are decided. A power plane is the counterpart to a ground plane and behaves as an AC signal ground while providing DC power to the circuits mounted on the PCB. Signal interconnections are traced on signal planes. Signal planes can be on the outer as well as inner layers. For optimal EMI performance high frequency signals are routed in internal layers between power or ground planes.

5. Line impedance is determined using dielectric layer thickness, routing copper thickness and trace-width. Trace separation is also taken into account in case of differential signals. Micro strip, strip line or dual stripline can be used to route signals.

6. Components are placed. Thermal considerations and geometry are taken into account. Vias and lands are marked.

7. Signal traces are routed. Electronic design automation tools usually create clearances and connections in power and ground planes automatically.

8. Gerber files are generated for manufacturing.

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Chapter 8

LED 8.1 Introduction Of LED A light-emitting diode (LED) is a two-lead semiconductor light source. It is a p–n junction diode, which emits light when activated. When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence, and the color of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor.An LED is often small in area (less than 1 mm2) and integrated optical components may be used to shape its radiation pattern.

Figure 8.1 Types Of LED

Figure 8.2 Construction of A LED

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Chapter 9 Circuit Diagram And Assembly

9.1Circuit Diagram a.Breadboard Model

Figure 9.1.Breadboard model of The H.P.M.

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b.Schametic model

Figure 9.2 Schametic model of The HPM

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c.PCB Model

Figure 9.3 PCB Model of The HPM

9.2 Circuit Assembly ATmega 328p-Pu—Power Supply

o 5v – VCC,AVCC o GND-GND,GND

HCSr-04 Ultrasonc Sensor--ATmega 328P-PU o Trig Pin - PD3 o Echo Pin – PD4 o Vcc - 5v o GND-GND

Buzzer - PD2(Atmega 328P-Pu0 Vibrator Motor – PD5

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Chapter 10 CODE

/*The Haptic Proximity Module (THE HPM) * by Sourabh Kumar & Jeetendra Kumar * www.androroot.com */ int buzzerPin = 2; //buzzer int buzzmot = 5; //vibrator int ledPin = 6;//indicator int pingPin = 3; //Trig int inPin = 4; //Echo int proximity=0; int duration; int distance; void setup() { pinMode(inPin, INPUT); pinMode(pingPin, OUTPUT); pinMode(buzzerPin, OUTPUT); pinMode(buzzmot, OUTPUT);

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pinMode(ledPin, OUTPUT); } void loop() { pinMode(ledPin, HIGH); digitalWrite(pingPin, HIGH); delayMicroseconds(500); digitalWrite(pingPin, LOW); duration = pulseIn(inPin, HIGH); distance = (duration/2) / 29.1; proximity=map(distance, 0, 60, 8, 0); if (proximity <= 0){ proximity=0; } else if (proximity >= 0 && proximity <= 2){ tone(buzzerPin, 250000, 200); digitalWrite(buzzmot, LOW); } else if (proximity >= 3 && proximity <= 4){

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tone(buzzerPin, 200000, 200); digitalWrite(buzzmot, HIGH); } else if (proximity >= 5 && proximity <= 6){ tone(buzzerPin,5000, 200); digitalWrite(buzzmot, HIGH); } else if (proximity >= 7 && proximity <= 8){ tone(buzzerPin, 1000, 200); digitalWrite(buzzmot, HIGH); } delay(300); noTone(buzzerPin); digitalWrite(buzzmot, LOW); }

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Chapter 11 Working of Circuit

1. Female USB will be connected with any power source like Power Bank or 9v Battery.

2. Switch the circuit ON. 3. After Switching it ON.ATmega 328P-Pu will send data to Ultrasonic to

Transmit and receive ECHO Sound. 4. After receiving Data Microcontroller will Convert it into Digital form

and calculates the Distance. 5. If distance will be More then 60cm then the Process will repeat from

Point (3). 6. If Distance will be less then 60 cm then Microcontroller will send data

to Buzzer and vibrater Motor. 7. Then Buzzer and vibrator Will warn the user. 8. 60 cm is divided into 4 part and every part having its diffrent Buzzer

Sound and Vibrating frequiency.

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Chapter 12

Pros and Cons

Pros o Very Helpful For Blind or low Vision People. o Can be used easily in Crowdy Places due to Vibrating Motor. o Good range <400cm o Warning Range can be adjusted through the modifying the code. o Diffrent type of Sound for Different Range/Distance. o Good Battery Backup due to the Voltage Regulator and circuit. o Long Life of device.

Cons

o Battery indicator is missing. o No Rechargable Batteries. o Anti-lost Alarm is Missing. o One device for one direction.

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FUTURE SCOPE

A RF-Module (Wireless Remote) Can be added which will notify the user when he lost the stick.

Add more devices (4) and it will warn you for All 4 Directions. The system can be supplemented with actual GPS MODULE used in cars. A voice Module Can Be added and it will all the details so it will be more user Friendly. Rechargable Battery with Battery Indicator by vibation.it will notify the user when battery

is low.

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CONCLUSION

This Project has been an attempt to develop portable Device to help Blind Or Low vision Peoples. This device has a buzzer and Vibrating motor and it will help blind people with the sound and vibration. The Haptic Proximity Module (HPM) seeks to enable people with low vision, or other vision impairments, to engage with their direct surroundings through vibration feedback from a range detector, and do so cheaply with readily available components. The aim of this project is to share the parts and process of creating this device in the hope that it will get shared and improved to become something beyond my current imagination! I also have hopes for it to allow one person to enable another through making this project and giving it away to someone who is experiencing vision impairment or loss, such as Low Vision. Interface was Successfully Developed.

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REFERENCES

1. www.google.com 2. www.instructable.com 3. www.wikipedia.com 4. www.instructables.com 5. www.sparkfun.com 6. www.slideshare.com 7. www.who.int/mediacentre/factsheets/fs282/en/ 8. “Project Prakash” http://web.mit.edu/bcs/sinha/prakash.html 9. G.Gayathri, “Smart Walking Stick for visually impaired” “http://ijecs.in/issue/v3-

i3/8%20ijecs.pdf”. 10. http://www.atmel.com/devices/atmega328.aspx