Final Report1

Digital Braille

Dept of Electronics and Communication, RVCE Page 1

Department of Electronics and Communication

R.V. College of Engineering

(An Autonomous Institution Affiliated to VTU, Belgaum)

DIGITAL BRAILLE

PROJECT REPORT

Submitted by

Dhananjaya Kumar A (1RV08EC031)

Kantharaj V (1RV08EC042)

Rakshith R (1RV08EC0123)

Rahul S Sankanur (1RV08EC077)

Under the Guidance of

Mrs Roopa J, Asst Professor

Department of Electronics and Communication Engineering

R.V.COLLEGE OF ENGINEERING,

BANGALORE-560059

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Dept of Electronics and Communication, RVCE Page 2

R.V. College of Engineering

(Autonomous under VTU , Belgaum)

Dept of Electronics & Communication Engineering

R.V. Vidyaniketan Post, Bangalore – 560 059

. CERTIFICATE

This is to certify that the project work entitled ―DIGITAL BRAILLE‖ is a bonafide work

carried out by

Dhananjaya Kumar A (1RV08EC031)

Kantharaj V (1RV08EC042)

Rakshith R (1RV08EC0123)

Rahul S Sankanur (1RV08EC077)

in partial fulfillment for the award of the degree of Bachelor of Engineering in Electronics

and Communication Engineering of Visvesvaraya Technological University, Belgaum

during the academic year 2011-2012 as a part of the 7th

semester mini project . It is certified

that all corrections/suggestions indicated for Internal Assessment have been incorporated in

the report deposited in the departmental library. The project report has been approved as it

satisfies the academic requirements in respect of project work prescribed for the said degree.

Signature of Guide Signature of Examiner

Mrs Roopa J

Asst Prof., ECE, RVCE

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ACKNOWLEDGMENT

The satisfaction that accompanies the successful

completion of any task would be incomplete without the

mention of the people who made it possible, whose constant

guidance and encouragement crowned all our efforts with

success. We consider our privilege to express gratitude and

thanks to the following persons for their help, encouragement

and intellectual influence during the course of the project

work.

We would like to thank Principal, R.V. College of engineering

and Prof. S. Jagannathan, head of Electronics and

Communication Engineering, RVCE, for inspiring words with

constant support extended to us during our entire course

period and for making the lab facilities available to us

whenever needed.

We sincerely thank our internal guide Mrs Roopa J, Asst

Professor, Department of Electronics and Communication

Engineering for the guidance regarding the project throughout

the entire period.

We thank all the faculty members of Department of

Electronics and Communication, our parents and friends for

their continuous support and encouragement throughout the

project work.

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CONTENTS

TOPICS PAGE NUMBER

Abstract 5

Introduction 6

Theory behind Project 7

System Overview 11

Programmer Design 13

Hardware Implementation 18

Software Implementation 20

Result and Analysis 29

Conclusion 31

Appendix 32

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Abstract

The project is the implementation of a product called DIGITAL BRAILLE. This product is

aimed at helping the visually impaired people to implement Braille code at ease and also

them communicate with the computer. It involves the implementation a key board where

inputs are such that it is similar that in the Braille script. The inputs are taken and processed

in the micro-controller. They are compared to a certain set of Braille-codes. Depending on the

code, suitable output is sent to the computer corresponding to the letter typed by the user.

In terms of system design and development , this study consists of both hardware and

software. The hardware used is the DIY Arduino board consisting of ATMEGA168

microcontroller. Along with it , the inputs are given through the six push buttons provided.

Programmer used is the USBasp in Arduino -022. FT 232 R is used for serial communication.

Codes are written in C language.

Presently , micro-phones are used extensively for the Visually impaired to interact with the

computer. This leads to a lot of errors since the input is analog voice . And moreover, in

places where they are required to give online exams , special arrangements since answers are

through voice.

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INTRODUCTION

The main problem of visually impaired people face is to communicate. They cannot read or

write as a normal man does. For this reason, Louis Braille developed a different method of

reading and writing and this language is called BRAILLE.

BRAILLE is a medium through which the visually impaired people can read and write.

However, the visually impaired people find it difficult to use BRAILLE as they have to keep

punching many holes in order to write even a single letter or a word. It also takes time for

them to read as well as they have to feel the punched holes and then identify each letter and

hence the work. This takes a very long time as well as very strenuous task and further more it

is difficult to be understood by a common man.

Therefore, our motive is to develop a product which should be an alternative to the current

BRAILLE and which can help the visually impaired people to communicate not only

amongst them but also among the whole world.

Our main objective is to help the visually impaired people to read and write with ease.

We are going to achieve this objective by implementing our product called DIGITAL

BRAILLE. Digital Braille is a product used to help the visually impaired people to interact

with the computer with the help of, microcontrollers and touch sensors or keypads. The

visually impaired people enter the Braille code using the touch sensors with ease as they

don‘t have to punch holes and this Braille code is decoded into the corresponding alphabet.

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THEORY BEHIND THE PROJECT

The Braille system is a method that is widely used by blind people to read and write, and was

the first digital form of writing.

The Braille system was based on a method of communication originally developed

by Charles Barbier in response to Napoleon's demand for a code that soldiers could use to

communicate silently and without light at night called night writing. Barbier's system of sets

of 12 embossed dots encoding 36 different sounds was too difficult for soldiers to perceive by

touch, and was rejected by the military. In 1821 he visited the National Institute for the Blind

in Paris, where he met Louis Braille. Braille identified the two major defects of the code:

first, by representing only sounds, the code was unable to give the orthography of the words;

second, the human finger could not encompass the whole symbol without moving, and so

could not move rapidly from one symbol to another. His modification was to use a 6 dot cell

— the Braille system — representing all the letters of the alphabet.

At first the system was a one-to-one transliteration of French, but soon various abbreviations

and contractions were developed, creating a system much more like shorthand.

FORM

Braille can be seen as the world's first binary encoding scheme for representing

the characters of a writing system. The system as originally invented by Braille consists of

two parts:

1. A character encoding for mapping characters of the French language to tuples of

six bits or dots.

2. A way of representing six-bit characters as raised dots in a Braille cell.

Today different Braille codes (or code pages) are used to map character sets of different

languages to the six bit cells. Different Braille codes are also used for different uses like

mathematics and music. However, because the six-dot Braille cell only offers 63 possible

combinations (26 - 1 = 63), of which some are omitted because they feel the same (having the

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same dots pattern in a different position, e.g. ⠊ and ⠔), many Braille characters have

different meanings based on their context. Therefore, character mapping is not one-to-one.

In addition to simple encoding, modern Braille transcription uses contractions to increase

reading speed.

WRITING DIGITAL BRAILLE

Braille may be produced using a slate and stylus in which each dot is created from the back

of the page, writing in mirror image, by hand, or it may be produced on a Braille typewriter

or Perkins Brailler, or produced by a Braille embosser attached to a computer. It may also be

rendered using a refreshable Braille display.

Braille has been extended to an 8-dot code, particularly for use with Braille embossers and

refreshable Braille displays. In 8-dot Braille the additional dots are added at the bottom of the

cell, giving a matrix 4 dot high by 2 dots wide. The additional dots are given the numbers 7

(for the lower-left dot) and 8 (for the lower-right dot). Eight-dot Braille has the advantages

that the case of an individual letter is directly coded in the cell containing the letter and that

all the printable ASCII characters can be represented in a single cell. All 256 (28) possible

combinations of 8 dots are encoded by the Unicode standard. Braille with six dots is

frequently stored as Braille ASCII.

The first ten letters of the alphabet are formed using only the top four dots (1, 2, 4, and 5).

Reminiscent of Greek numerals, these symbols also represent the digits 1 through 9 and

0 (preceded by the symbol [number follows]; [number follows]j also stands for 10, within

context).[5]

Adding dot 3 forms the next ten letters, and adding dot 6 forms the last six letters

(except w) and the words and, for, of, the, and with. Omitting dot 3 from the letters U-Z and

the five word symbols form nine digraphs (ch, gh, sh, th, wh, ed, er, ou, and ow) and the

letter w.

Fig.1 Shows the Braille code implementations for different letters and other symbols. It also

shows Braille contractions to implement small words using the Braille code.

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PAGE DEMENSIONS

Most Braille embossers support between 34 and 37 cells per line, and between 25 and 28

lines per page. A manually-operated Perkins Braille typewriter supports a maximum of 42

cells per line (its margins are adjustable), and typical paper allows 25 lines per page. A large

interlining Stains by has 36 cells per line and 18 lines per page. An A4-sized Marburg Braille

frame, which allows interpoint Braille (dots on both sides of the page, positioned out of

phase so they do not interfere with each other) has 30 cells per line and 27 lines per page.

A refreshable Braille display typically has one line of between 18 and 40 cells, although 80 is

possible.

Fig.1 Braille code implementations of various alphabet

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Fig 2. Braille code implementations (GRADE 2 BRAILLE)

Braille Unicode

Braille was added to the Unicode Standard in September, 1999 with the release of version

3.0.

The Unicode block for Braille is U+2800 ... U+28FF:

Unicode is a computing industry standard for the consistent encoding, representation and

handling of text expressed in most of the world's writing systems. Developed in conjunction

with the Universal Character Set standard and published in book form as The Unicode

Standard, the latest version of Unicode consists of a repertoire of more than

109,000 characters covering 93 scripts, a set of code charts for visual reference, an encoding

methodology and set of standard character encodings, an enumeration of character properties

such as upper and lower case, a set of reference data computer files, and a number of related

items, such as character properties, rules for normalization, decomposition, collation,

rendering, and bidirectional display order (for the correct display of text containing both

right-to-left scripts, such as Arabic and Hebrew, and left-to-right scripts).[1]

As of 2011, the

most recent major revision of Unicode isUnicode 6.0.

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SYSTEM OVERVIEW

IMPLEMENTATION

We have 6 variables depicting the 6 dots in the Braille. These 6 keys are used to represent all

the alphabets through various permutations. The 26 alphabets are divided in 3 groups of 10,

10 and 6.There is a vast similarity of codes introduced between these groups to have greater

simplicity.

To distinguish between the alphabets of one group to another, GROUP SELECTORS are

used. S3 and s6 are used.

Fig.4 Shows the picture of BRAILLE keypad which we are going to use in DIGITAL Braille

for entering the Braille code.

Fig 4.Digital Braille Keypad

The group selectors are implemented as shown in the example below and note

the use of line selectors in ‗K‘ and ‗U‘.

Alphabets Keys

A s1

B s1,s2

C s1,s4

K s1,s3

U s1,s3,s6

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Fig 5. Braille codes

The fig 6.shows the basic block diagram of DIGITAL BRAILLE.

Fig 6.Block diagram of Digital Braille

The integral part of DIGITAL BRAILLE is ATMEGA168 Microcontroller. We are using 6

keys keypad to enter the Braille code. The six keys as shown in the fig 6 is used to simulate

the six dots of the Braille Cell. After the Braille code is entered in the keypad, the

ATMEGA168 microcontroller decodes the entered digital Braille code into English alphabets

by using a look up table. . Once the Braille code has been decoded, it is converted to speech

using APIs provided by windows. This enables the visually impaired people to keep track of

what code they are entering.

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PROGRAMMER DESIGN

ARDUINO MICRCONTROLLER BOARD

The Arduino microcontroller board is one of the integral parts of DIGITAL BRAILLE. It is

used for programming the ATMEGA168 microcontroller.

Fig 7. Arduino UNO Board

Fig. 7 shows the original Arduino UNO board.

However, we have developed our own Arduino board as shown in the fig 8.

Fig 8. DIY – DUINO

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FEATURES OF ARDUINO WE USED:-

POWER

The Arduino Uno can be powered via the USB connection or with an external power

supply. The power source is selected automatically.

External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or

battery. The adapter can be connected by plugging a 2.1mm center-positive plug into the

board's power jack. The board can operate on an external supply of 7 to 12 volts.

The power pins are as follows:

VIN: The input voltage to the Arduino board when it's using an external power

source.

5V: The regulated power supply used to power the microcontroller and other

components on the board.

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

is 50mA.

GND: Ground pins.

MEMORY

The ATmega168 has 16 KB (with 0.5 KB used for the boot loader).

It also has 1 KB of SRAM and 512 B of EEPROM.

INPUT AND OUTPUT

Each of the 14 digital pins on the Uno can be used as an input or output, using

pinMode(), digitalWrite() and digitalRead() functions. They operate at 5 volts. Each pin can

provide or receive a maximum of 40 mA and has an internal pull-up resistor of 20-50k Ohms.

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Additional functions (digital):

Serial: 0 (RX) and 1 (TX): Used to receive (RX) and transmit (TX) TTL serial data.

These pins are connected to the corresponding pins of the FT232R USB-to-TTL

Serial chip.

External Interrupts: 2 and 3: These pins can be configured to trigger an interrupt on

a low value, a rising or falling edge, or a change in value.

PWM: 3, 5, 6, 9, 10, and 11: Provide 8-bit PWM output with the analogWrite()

function.

SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK): These pins support SPI

communication using the SPI library.

LED: 13: There is a built-in LED connected to digital pin 13(active high).

The Uno has 6 analog inputs, labeled A0 through A5, each of which provide 10 bits of

resolution (i.e. 1024 different values).

Additional functions (analog):

I2C: 4 (SDA) and 5 (SCL): Support I2C (TWI) communication using the Wire

library.

Reset: Bring this line LOW to reset the microcontroller.

COMMUNICATION

The Arduino Uno has a number of facilities for communicating with a computer,

another Arduino, or other microcontrollers. The ATmega168 provides UART TTL (5V)

serial communication, which is available on digital pins 0 (RX) and 1 (TX). An ATmega8U2

on the board channels this serial communication over USB and appears as a virtual com port

to software on the computer. The Arduino software includes a serial monitor which allows

simple textual data to be sent to and from the Arduino board. The RX and TX LEDs on the

board will flash when data is being transmitted via the USB-to-serial chip and USB

connection to the computer. A Software Serial library allows for serial communication on any

of the Uno's digital pins.

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The ATmega168 also supports I2C (TWI) and SPI communication. The Arduino

software includes a Wire library to simplify use of the I2C bus; see the documentation for

details. For SPI communication, use the SPI library.

PROGRAMMING

The ATmega168 on the Arduino Uno comes pre-burned with a boot loader that

allows you to upload new code to it without the use of an external hardware programmer. It

communicates using the original STK500 protocol.

AUTOMATIC (SOFTWARE) RESET

Arduino Uno can be reset using software. One of the hardware flow control lines

(DTR) of the FT232R is connected to the reset line of the Atmega168 via capacitor. When

this line is taken low, the reset line drops long enough to reset the chip.

STEPS TO PREPARE DIY ARDUINO BOARD

We take rectangular copper board 8‖ x 12‖. Sand the top of the copper with a fine sand

paper. This gives it some more surface area for the toner to stick to.

The pattern is transferred on the PCB by ironing the pattern on the PCB.

Etch the board using FeCl3.

After performing the above three steps, the board looks like as shown in fig 9.

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Fig 9. Pattern trancfered onto copper board

The holes are drilled and all the components are placed as shown in fig 10.

Fig 10. Arduino board with all the components placed.

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HARDWARE IMPLEMENTATION

1. DIY Arduino board with Atmega168 Microcontroller

2. Matrix keypad

3. PCB

4. FT232 CABLE

5. Resistors, capacitors, multimeters

6. Soldering gun

INTERFACING OF KEYBOARD WITH ATMEGA168

Fig 11. Interfacing of keypad with atmega168

The keypad is interfaced with the atmega168 as shown in the figure 11.

Identifying the keypad pins

We require 6 push buttons to represent the 6 dots of the Braille cell.

We attached 6 SPDT push buttons the board. SPDT push buttons mean single pole double

throw Push Button. The switch has a contact arm that is connected to a actuating force with

that actuating force counteracted by another force (such as a spring). The actuating force may

be a pressure source, as a pressure switch, a flow, as a sail switch, a lever, as in a position

switch.

The single pole defines that the switch may be connected to a single power source, the

terminal is typically denoted as C for common.

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The double throw means that the switch arm has 2 electrical contacts. The normally open

contact, typically denoted as NO, is open with the switch not actuated (power may NOT flow

through this contact when the switch is in its unactuated state). The normally closed, typically

denoted as NC, is closed when the switch is unactuated (power may flow through this contact

when the switch is in its unactuated state) and is connected to the ground. When the force

actuates the switch, contact closure reverses (power may flow through the NC switch and

may NOT flow through the NO switch).

Diagram:

||-----C----|/|

NO--C—NC

The power leg is connected to C and the switch leg(s) are connected to the NO or NC or the

ground.

The 6 keys are named K1, K2, K3, K4, K5, and K6.

Key K1 is attached to PIN 2, Key K2 is attached to PIN 3, Key K3 is attached to PIN 4, Key

K4 is attached to PIN 5, Key K5 is attached to PIN 6, and Key K6 is attached to PIN 7.

Using these six keys, we are implementing Braille code. We have given a some delay while

programming and we have to press all the push buttons to enter the required letter within this

delay to obtain the required letter else only those buttons which have been pressed within that

delay while be considered and the corresponding letter of that code will be displayed. The

delay we have given is around 500 milliseconds.

Which ever button is actuated, the corresponding input pin will receive a logic one. After the

said delay, the output is sent to the serial window using a FT232 cable. This cable is used for

converting serial to USB as the USB is attached to the USB port of the computer where we

see the output in the serial window.

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SOFTWARE IMPLEMENTATION

FLOW CHART

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The above is the flow chart of the code used for implementing Digital Braille using Arduino

programmer for programming Atmega168.

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CODE SNIPPET

/* Initializing the input and output pins of Atmega168 and setting up the baud rate to 9600*/

void setup()

{

Serial.begin(9600);

pinMode(2,INPUT);

pinMode(3,INPUT);

pinMode(4,INPUT);

pinMode(5,INPUT);

pinMode(6,INPUT);

pinMode(7,INPUT);

}// End of setup

/* Starting of infinite loop */

void loop()

{

/* assigning input to the variables */

int a = digitalRead(2);

int b = digitalRead(3);

int c = digitalRead(4);

int d = digitalRead(5);

int e = digitalRead(6);

int f = digitalRead(7);

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if(e&f&!a)

{

if(!b)

{

if(!d)

{

if(!c)

Serial.println('G'); //print letter G serially

else

Serial.println('D'); //print letter D serially

}

else if(!c)

Serial.println('F'); //print letter F serially

else

Serial.println('C'); //print letter C serially

}

else if(!c)

{

if(!d)

Serial.println('H'); //print letter H serially

else

Serial.println('B'); //print letter B serially

}

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else if(!d)

Serial.println('E'); //print letter E serially

else

Serial.println('A'); //print letter A serially

}

else if(!b)

{

if(!d&!c&f&e)

{

Serial.println('J'); //print letter J serially

}

else if(!c&f&e)

{

Serial.println('I'); //print letter T serially

}

}

if(f&!e)

{

if(!a)

{

if(!b)

{

if(!d)

{

if(!c)

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Serial.println('Q'); //print letter Q serially

else

Serial.println('N'); //print letter N serially

}

else if(!c)

Serial.println('P'); //print letter P serially

else

Serial.println('M'); //print letter M serially

}

else if(!c)

{

if(!d)

Serial.println('R'); //print letter R serially

else

Serial.println('L'); //print letter L serially

}

else if(!d)

Serial.println('O'); //print letter O serially

else

Serial.println('K'); //print letter K serially

}

else if(!b)

{

if(!d&!c)

{

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Serial.println('T'); //print letter T serially

}

else if(!c)

{

Serial.println('S'); //print letter S serially

}

}

}

if(!e&!f)

{

if(!a)

{

if(!b)

{

if(!d)

Serial.println('Y'); //print letter Y serially

else

Serial.println('X'); //print letter X serially

}

else if(!c)

Serial.println('V'); //print letter V serially

else if(!d)

Serial.println('Z'); //print letter Z serially

else

Serial.println('U'); //print letter U serially

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}

}

if(a&!b&!c&!d&e&!f)

Serial.println('W'); //print letter W serially

/* to give sufficient delay to press all the keys */

delay(500);

} //End of void loop

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REFLECTIONS

Result

The project demonstrates as to how the visually impaired people can write the Braille code

using keypads interfaced with the microcontroller (or computer).

The 6 keys on the keypad depict the 6 dots on the Braille cell used by the visually impaired

people to write the Braille code. The keypad is interfaced with the ATMEGA168

microcontroller. The required Braille code is entered using the keypad and the input to this

keypad is sent to the microcontroller. The microcontroller then decodes the entered Braille

code to the corresponding English alphabets and displayed on the serial window. Hence, as

the Braille code entered is translated into English, even people who do not know the Braille

code can understand what the visually impaired people are writing.

The following are the results we have obtained from the implementation of the DIGITAL

BRAILLE.

Inputs from the keys Obtained

Alphabet

Required

Alphabet K6 K5 K4 K3 K2 K1

0 0 0 0 0 1 A A

0 0 0 1 0 1 B B

0 0 0 0 1 1 C C

0 0 1 0 1 1 D D

0 0 1 0 0 1 E E

0 0 0 1 1 1 F F

0 0 1 1 1 1 G G

0 0 1 1 0 1 H H

0 0 1 0 1 0 I I

0 0 1 1 1 0 J J

0 1 0 0 0 1 K K

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0 1 0 1 0 1 L L

0 1 0 0 1 1 M M

0 1 1 0 1 1 N N

0 1 1 0 0 1 O O

0 1 0 1 1 1 P P

0 1 1 1 1 1 Q Q

0 1 1 1 0 1 R R

0 1 0 1 1 0 S S

0 1 1 1 1 0 T T

1 1 0 0 0 1 U U

1 1 0 1 0 1 V V

1 0 1 1 1 0 W W

1 1 0 0 1 1 X X

1 1 1 0 1 1 Y Y

1 1 1 0 0 1 Z Z

Learning

There are millions of visually impaired people around the world and these people find

it difficult to write the Braille code as they have to keep punching holes on the Braille

cell. As students, we feel privileged to have developed a product which helps the

visually impaired people to easily write the Braille code and also interact with other

people.

Our programming and logic analyzing skills were tested and bettered as we coded for

the project

We learnt a great deal with certain aspects of controllers as we implemented our

theoretical knowledge and also expanded our horizons to the practical world.

Finally, we learnt to work as a team and support each other through the course of the

project.

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CONCLUSION

The project successfully demonstrates the implementation of the Braille code using

microcontrollers.

Digital Braille can be implemented on large scale due to the following advantages: -

It mainly helps the visually impaired people to enter the Braille code with utmost ease

as they don‘t have to keep punching holes on the Braille cell on the paper.

Since the entered Braille code is converted to corresponding English words, people who

do not know Braille can also understand what a visually impaired person is typing in the

Braille code.

During any exams, the visually impaired people are given external help by appointing a

person to write down the answers for them. With the implementation of the Digital

Braille, this problem is solved as the visually impaired people need not have external

aide to write his answers. This is because the entered Braille code is converted to

English or for the matter any corresponding language and it is easy for the examiner to

understand what answers the visually impaired people have written. Digital Braille thus

helps the people to live independently and don‘t have to rely on others for written any

exams.

It is one time investment which can be used throughout the life time.

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APPENDIX

ATMEGA168 DATASHEET

We are using ATMEGA168 microcontroller for implementation of DIGITAL BRAILLE.

The following are the features of ATMEGA168 microcontroller:

Features:

High Performance, Low Power Atmel AVR 8-Bit Microcontroller

Advanced RISC Architecture

32 x 8 General Purpose Working Registers

Fully Static Operation

Up to 20 MIPS Throughput at 20MHz

On-chip 2-cycle Multiplier

High Endurance Non-volatile Memory Segments

16KBytes of In-System Self-Programmable Flash program memory

512 Bytes EEPROM

1KBytes Internal SRAM

Write/Erase Cycles: 10,000 Flash/100,000 EEPROM

Optional Boot Code Section with Independent Lock Bits

In-System Programming by On-chip Boot Program

True Read-While-Write Operation

Peripheral Features

Two 8-bit Timer/Counters with Separate Pre-scalar and Compare Mode One

16-bit timer/Counter with Separate Pre-scalar, Compare Mode, and Capture

I/O and Packages

23 Programmable I/O Lines

28-pin PDIP

Operating Voltage:

1.8 - 5.5V

Temperature Range:

-40°C to 85°C

Speed Grade:

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0 - [email protected] - 5.5V, 0 - [email protected] - 5.5.V, 0 - 20MHz @ 4.5 - 5.5V

Power Consumption at 1MHz, 1.8V, 25°C

Active Mode: 0.2mA and Power-down Mode: 0.1μA

Power-save Mode: 0.75μA (Including 32kHz RTC)