Final Report Safety Guard Blind

7/22/2019 Final Report Safety Guard Blind

1/32

SUMMER TRAINING REPORT

SAFETY GUARD FOR BLIND

BACHELOR OF TECHNOLOGY

ECE

(2010-14)

UNDER THE GUIDENCE OF: Submitted by:

Mr. Y.S. TANWAR ASHUTOSH DABAS

2363014

ECE-A

7TH SEM

KIIT COLLEGE OF ENGINEERING, GURGAON

APPROVED BY AICTE & AFFILATED TO MDU, ROHTAK


2/32

ACKNOWLEDGEMENT

The submission of this industrial training report gives us an opportunity to convey

our gratitude to all those who have helped us reach a stage where we have

immense confidence to launch our career in the competitive world of electronics

& communication technology.

We have no second thought to admit that it is our respected teachers who have

played a significant role in shaping our career and we would be miserable failing

in our duty if dont extend our heart filled gratitude and acknowledgement to our

guide Mr. Y.S. Tanwar who has been a source of perpetual inspiration to us,

gently guiding and our waves towards a bright career. You were ever willing to

give all kind of support and encouragement.

In the end we want to thankful our Parents, Embedded teachers and Almighty

GOD for all the thing that they do to us.


3/32

ABSTRACT

Blindness is not a new phenomenon in the society. It is a condition of

lacking visual perception and always described as severe visual impairment with

residual vision. The legally blind people are those who have the visual acuity of

20/200 or (6/60). It means that a blind person needs to stand within 20 feet (6

meters) to see an object which someone with normal visual acuity can see from

200 feet (60 meters) away. The legally blind people has trouble seeing things

which other people take for granted, like road signs, traffic lights, and so forth.

They are more prone to falls and other accidents because they cannot clearly

discern their surrounding environment. The visually challenged people or the

blind people are always trying their best to be normal and comfortable insurroundings. However their life and activities are greatly restricted by loss of

eyesight.

Many people with serious visual impairments can travel independently, using a

wide range of tools and techniques. They are taught how to travel safely,

confidently, and independently in the home and the community. They can find

the way easily if they are familiar with an environment or route. The most

important mobility aid used by them is a walking stick or also known as walking

cane. The conventional walking stick employed by the visually challenged peopleis actually not efficient to detect the object in front of the user. They can only

detect the object that is being hit by the walking stick. A walking stick for the

visually challenged people using the infrared distance sensor will become a great

help to them because this kind of walking stick is able to detect the object in the

specific range. In this project the distance range used is 10cm to 80 cm. When an

object is detected, sound alarm from a buzzer will alert the user about the object

and the person can avoid the object safely without hitting the object. As the

distance of the object and the user is closer, the loudness of the buzzer is

increasing. The user is able avoid the obstacles better using the newly designed

walking stick.


4/32

PREFACE

Summer Training / Industrial Training is very important for engineering students.

This training provides them opportunity to be familiar with the industrial /

company environment. During this training they can show and can enhance their

practical skills and gain practical knowledge and experience for future. This is best

way through which the students can learn the latest technologies being used in

the companies.

I, Ashutosh Dabashave undergone through a Summer Training from Ministry of

Electronics and Information Technology This training helped me a lot in learning

the technologies of this particular field. I have also done a project Safety Guard

for Blind during the training. During the project development I gained practical

knowledge of the subject.

Industrial Training & Project work were very challenging but as I proceeded things

got easier. Practical Summer/ Industrial Training was an interesting learning

experience for me.


5/32

CONTENTS

Introduction Circuit Design Transmitter Section

NESS Timer IC Features Description Block Diagram Pin Description

Receiver Section LM7805

Features Description Block Diagram Pin Description

LM311 Features Description Block Diagram


6/32

Switching Section AT89c51

Features Description Block Diagram Pin Description

Voice Processor Section ISD1420

Features Block Diagram Pin Description

Designing Circuit Board Program Conclusion


7/32

INTRODUCTION

Helping in need is humanity. In order to help blind people and make their life easier here

safety guard for the blind using microcontroller AT89c51 is designed. This system detects

obstacles within 1 meter in the path and alerts the users.

Circuit descriptionThe entire hardware circuit of safety guard for blind is divided into four major sections. i.e.

transmitter, receiver, switching section, and the voice processing section.

Transmitter sectionThe logic of this section is simple and is build around most versatile IC NE555 (IC1), configured

as astable multivibrator to produce frequency about 38 KHz. This is so, because IR module

receiver used here works in range of 38 KHz frequency. Timing component of this circuit is

resistor VR1 and R1 and capacitor C2, determine the range of oscillating. Where, formula of

generated frequency (F) from transmitter section is given by

F = 1.443 / (R1 + 2R2) C2

The output frequency from pin 3 of IC1 is fed to base of transistor T1 through resistor R3.Transistor T1 is configured as Darlington pair with transistor T2 in order to drive pair of IR LED

connected in series as shown in figure 2. LED1 is used as transmitted signal indicator and

resistor R5 is used as current limiter.


8/32

NE555 TIMER IC:

Features:

Low turn off time Maximum operating frequency greater than500khz. Timing from microseconds to hours. Operates in both astable and monostable modes. High output current can source or sink 200mA. Adjustable duty cycle. TTL compatible. Temperature stability of 0.005% peroc.

Description:

TheNE555monolithic timing circuit is a highly stable controller capable of producing accurate

time delays or oscillation. In the time delay mode of operation, the time is precisely controlled

by one external resistor and capacitor. For a stable operation as an oscillator, the free running

frequency and the duty cycle are both accurately controlled with two external resistors and one

capacitor. The circuit may be triggered and reset on falling waveforms, and the output structure


9/32

can source or sink up to 200mA. The NE555 is available in plastic and ceramic mini dip package

and in an 8-leadmicropackage and in metal can package version.

BLOCK DIAGRAM

PIN CONNECTIONS:


10/32

Pin Description:

Pin 1 (Ground):

Connects to the 0v power supply.

Pin 2 (Trigger):

Detects 1/3 of rail voltage to make output HIGH. Pin 2 has control over pin 6. If pin 2 is LOW,and pin 6 LOW, output goes and stays HIGH. If pin 6 HIGH, and pin 2 goes LOW, output goes

LOW while pin 2 LOW. This pin has very high impedance (about 10M) and will trigger with

about 1uA.

Pin 3 (Output) :

(Pins 3 and 7 are "in phase.") Goes HIGH (about 2v less than rail) and LOW (about 0.5v less than

0v) and will deliver up to 200mA.

Pin 4 (Reset):

Internally connected HIGH via 100k. Must be taken below 0.8v to reset the chip.

Pin 5 (Control):

A voltage applied to this pin will vary the timing of the RC network (quite considerably).Pin 6 (Threshold):

Detects 2/3 of rail voltage to make output LOW only if pin 2 is HIGH. This pin has a very high

impedance (about 10M) and will trigger with about 0.2uA.

Pin 7 (Discharge):

Goes LOW when pin 6 detects 2/3 rail voltage but pin 2 must be HIGH. If pin 2 is HIGH, pin 6 can

be HIGH or LOW and pin 7 remains LOW. Goes OPEN (HIGH) and stays HIGH when pin 2 detects

1/3 rail voltage (even as a LOW pulse) when pin 6 is LOW. (Pins 7 and 3 are "in phase.") Pin 7 is

equal to pin 3 but pin 7 does not go high - it goes OPEN. But it goes LOW and will sink about

200mA.

Pin 8 (Supply):

Connects to the positive power supply (Vs). This can be any voltage between 4.5V and 15V DC,

but is commonly 5V DC when working with digital ICs.


11/32

Receiver section

When transmitted signal from transmitter is obstructed by any object lies in its path then the

transmitted signal is reflected. The reflected signal is received by IR receiver module

(TSOP1738) and is fed to base NPN transistor T3 through resistor R6 for amplification. Amplifiedsignal is again amplified by pair of transistor T4 and T5 up to necessary level. The output from

emitter of transistor T5 is fed through resistor R13 to pin 2 (non-inverting input) of comparator

(IC3) where inverting input is connected to zener diode ZD1. The output is taken from pin 7 and

is fed to I/O port P1.0 of microcontroller AT89c51 (IC4). The output of pin 7 of IC3 goes high

only when non-inverting input is more the inverting input (2.2V).

LM7805 (+5 Volt regulator):

Features:

Output Current up to 1A

Output Voltages of 5, 6, 8, 9, 10, 12, 15, 18, 24V

Thermal Overload Protection

Short Circuit Protection

Output Transistor Safe Operating Area Protection


12/32

Description:

The LM7805 of three terminal positive regulators are available in the TO-220/D-PAK package

and with several fixed output voltages, making them useful in a wide range of applications.

Each type employs internal current limiting, thermal shut down and safe operating area

protection, making it essentially indestructible. If adequate heat sinking is provided, they can

deliver over 1A output current. Although designed primarily as fixed voltage regulators, these

devices can be used with external components to obtain adjustable voltages and currents.

Internal Block Diagram


13/32

PIN CONNECTIONS:

LM311 Single Comparator:

Features:

Low input bias current: 250nA (Max)

Low input offset current: 50nA (Max)

Differential Input Voltage: 30V

Power supply voltage: single 5.0V supply to 15V.

Offset voltage null capability.

Strobe capability

Description:

The LM311 series is a monolithic, low input current voltage comparator. The device is also

designed to operate from dual or single supply voltage.


14/32

Internal Block Diagram


15/32

Switching (Microcontroller) Section

Here, we use microcontroller AT89c51 for only switching circuit because of availability and to

show how to interface an embedded system in a homemade project. Microcontroller section is

replaced by any switching circuit. Pin 1 through 4 (P1.0 through P1.3) is used as input port andpin 21 through 24 (P2.0 through P2.3) is used as output port. The output from pin 7 of IC3 is

connected to pin 1 (P1.0) and its corresponding output is obtained at pin 21 (P2.0). The output

from microcontroller (IC4) is fed to base of PNP transistor (T6) through resistor R18.

The output of transistor T6 from collector is fed through resistor R19 to base of relay driver

transistor T7 in order to energize the relay RL1 and is indicated by glowing LEDLED4.

When no signal is applied at input port 1.0, output port 2.0 is high and vice-versa. As transistorT6 is PNP, low at P2.0 conduct it.


16/32

AT89c51 (microcontroller chip):

Features

Compatible with MCS-51 Products

4K Bytes of In-System Reprogrammable Flash Memory

Endurance: 1,000 Write/Erase Cycles

Fully Static Operation: 0 Hz to 24 MHz

Three-level Program Memory Lock

128 x 8-bit Internal RAM

32 Programmable I/O Lines

Two 16-bit Timer/Counters

Six Interrupt Sources

Programmable Serial Channel

Low-power Idle and Power-down Modes

Description:

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

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

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

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

be reprogrammed in-system or by a conventional nonvolatile memory programmer. By

combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a

powerful microcomputer which provides a highly-flexible and cost-effective solution to many

embedded control applications.

The AT89C51 provides the following standard features: 4Kbytes of flash, 128 bytes of RAM, 32

I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex

serial port and on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with

static logic for operation down to zero frequency and supports two software selectable power

saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port

and interrupt system to continue functioning. The Power-down Mode saves the RAM contents

but freezes the oscillator disabling all other chip functions until the next hardware reset.


17/32

Block Diagram


18/32

Pin Configurations

Pin Description

VCC

Supply voltage.

GNDGround.

Port 0

Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink eight

TTL inputs. When 1s are written to port 0 pins, the pins can be used as high impedance inputs.

Port 0 may also be configured to be the multiplexed low order address/data bus during

accesses to external program and data memory. In this mode P0 has internal pull-ups.

Port 0 also receives the code bytes during Flash programming, and outputs the code bytes

during program verification. External pull-ups are required during program verification.

Port 1

Port 1 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 1 output buffers can

sink/source four TTL inputs. When 1s are written to Port 1 pins they are pulled high by the

internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally being


19/32

pulled low will source current (IIL) because of the internal pull-ups. Port 1 also receives the low-

order address bytes during Flash programming and verification.

Port 2

Port 2 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 2 output buffers can

sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled high by the

internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are externally being

pulled low will source current (IIL) because of the internal pull-ups.

Port 2 emits the high-order address byte during fetches from external program memory and

during accesses to external data memory that uses 16-bit addresses (MOVX @ DPTR). In this

application, it uses strong internal pull-ups when emitting 1s. During accesses to external data

memory that uses 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special

Function Register.

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 bi-directional I/O port with internal pull-ups.

The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins they are

pulled high by the internal pull-ups and can be used as inputs. As inputs,

Port 3 pins that are externally being pulled low will source current (IIL) because of the pull-ups.

Port 3 also serves the functions of various special features of the AT89C51 as listed below:

Alternate Functions

P3.0 RXD (serial input port)

P3.1 TXD (serial output port)

P3.2 INT0 (external interrupt 0)

P3.3 INT1 (external interrupt 1)

P3.4 T0 (timer 0 external input)

P3.5 T1 (timer 1 external input)


20/32

P3.6 WR (external data memory write strobe)

P3.7 RD (external data memory read strobe)

Port 3 also receives some control signals for Flash programming and verification.

RSTReset input. A high on this pin for two machine cycles while the oscillator is running resets the

device.

ALE/PROG

Address Latch Enable 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.

In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may

be used for external timing or clocking purposes. Note, however, that one ALE pulse is skippedduring each access to external Data Memory.

If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set,

ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high.

Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.

PSEN

Program Store Enable is the read strobe to external program memory.

When the AT89C51 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. Note, however, that if

lock bit 1 is programmed, EA will be internally latched on reset.

This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming,

for parts that require 12-volt VPP.

XTAL1

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

XTAL2

Output from the inverting oscillator amplifier.


21/32

Voice Processor

The entire circuit of voice processing is designed around IC ISD1420 (IC5) which is 28-pin chip by

Winbond. The voice message up to 20 seconds is recorded by this IC.

The recording process is done by pressing switch SW4 and the recorded message is played by

using pin 23. The condenser microphone pickup the voice message and changed it into

corresponding electrical signal connected to pin 17 and 18 via capacitor C13 and C10

respectively.

Pin 14 and pin 15 is connected to headphone jack or loudspeaker through coupling capacitor

C14 for playing message. Volume is controlled by variable resistor VR2.


22/32

ISD1420 (voice processor):

GENERAL DESCRIPTION

Win bonds ISD1400 Chip order series provide high-quality, single-chip, Record/Playback

solutions to short-duration messaging applications. The CMOS devices include an on-chip

oscillator, microphone preamplifier, automatic gain control, anti-aliasing filter, smoothing filter,

and speaker amplifier. A minimum Record/Playback subsystem can be configured with a

microphone, a speaker, several passive components, two push buttons and a power source.

Recordings are stored into on chip non-volatile memory cells, providing zero-power message

storage. This unique, single-chip solution is made possible through Win bonds patented Multi-

Level Storage (MLS) technology. Voice and audio signals are stored directly into memory in their

natural form, providing high-quality, and solid state voice reproduction.

FEATURES

Single +5 volt power supply

Duration: 14 and 20 seconds.

Easy-to-use single-chip, voice record/playback solution

High-quality, natural voice/audio reproduction

Manual switch or microcontroller compatible Playback can be edge- or level-activated

Directly cascadable for longer durations

Automatic power-down (push-button mode)

o Standby current 1 A (typical)

Zero-power message storageo Eliminates battery backup circuits

Fully addressable to handle multiple messages

100-year message retention (typical)

100,000 record cycles (typical)

On-chip oscillator

Programmer support for play-only applications

Available in die, PDIP and SOIC

Temperature:

Commercial - Packaged unit : 0C to 70C, Die : 0C to 50C Industrial - Packaged unit : -40C to 85C


23/32

BLOCK DIAGRAM

Pin Description


24/32


25/32


26/32


27/32

Designing a circuit board

After many experiments on a prototyping board, when I found an already working circuit, I

decided to create my own compact etched board because the prototyping board was too bigfor my robot. I designed the circuit scheme in program EAGLE and then I generated a plan of

the circuit board. It is very interesting how the program EAGLE works. You only have to place

the components on the board and the EAGLE makes the connections between components in a

way that no wire crosses any other. You must place the components advisedly to simplify the

final board and to reduce the number of unlinked points. As it was my first board, I decided to

make it only single-sided. However, several points could not be linked on one-sided board and I

had to connect them manually with a wire. The Light version of EAGLE is free, but it allows you

to make the boards not bigger than 8 10 cm (These measurements were enough for my

project). The number of components is not limited in the Light version.

Figure 1: Designing a board in EAGLE


28/32

Making a circuit board

I redrew final plan using etch-resistant ink to a copper sheet laminated onto a non-conductive

substrate. Then I sank the board into the FeCl3 that caused etching unwanted copper from the

board.

After that I drilled holes for components into the board. And finally I soldered the components

with a soldering gun. It is not good to solder integrated circuits directly into a board; it is better

to put them into sockets. The integrated circuit can be then easily removed and replaced.

External sensors, engines and power supply are attached to the board with keyed connectors.

Figure 2: My first circuit board


29/32

PROGRAM

The source code for safety guard for blind is written in C-programming language.

#include

#include

sbit t0=P1^0;

sbit t1=P1^1;

sbit t2=P1^2;

sbit t3=P1^3;

sbit t4=P2^0;

sbit t5=P2^1;

sbit t6=P2^2;

sbit t7=P2^3;

sbit t8=P2^4;

sbit t9=P1^5;

sbit t10=P1^6;

sbit t11=P1^7;

sbit t12=P2^5;

sbit t13=P2^6;

sbit t14=P2^7;

void main()

{

t9=t10=t11=t12=t13=t14=0;

t0=1; t1=1;t2=1;t3=1;//t3=t2=t1=t0=1;

for(; ;)


30/32

{

l1: if(t0==0)

{

t4=1;

t5=t6=t7=t8=0;

goto l1;

}

l2:if(t1==0)

{

t5=1;

t4=t6=t7=t8=0;

goto l2;

}

l3:if(t2==0)

{

t6=1;

t4=t5=t7=t8=0;

goto l3;

}

l4:if(t3==0)

{

t7=1;

t4=t5=t6=t8=0;

goto l4;


31/32

}

t8=1;

t4=t5=t6=t7=0;

}

}


32/32

CONCLUSION:

This is the first step of making safety guard for blind is capable of making theirown decisions on the situations provided. The design, implementation and testing

of a working project proved to be very challenging. The primary objective of

detecting and informing about the objects ahead proved to be a great learning

experience, as we did not have prior hands-on experience in Embedded Systems.

The difficulties in project management as well as those brought to light during

experimentation provided an opportunity to work on problem-solving

abilities. Despite many problems encountered, I found this experience a

rewarding and educational one. This project is application based as it has an

application for blind people. It can be further improved to have more decision

taking capabilities by employing varied types of sensors and thus could be used

for different applications.

Documents

Final Report Safety Guard Blind