BLIND AID synopsis.docx

7/27/2019 BLIND AID synopsis.docx

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BLIND AID

Introduction

Blind Aid is a portable tool that helps to study Braille letters and signals

close objects. It is ideal for those unfortunate people who just turned blind and

have not mastered Braille reading. It can also be used as a learning instrument

that helps the user decipher Braille without constantly going to the Braille

dictionary. It also has an obstacle detection sensor to avoid from any collision.

What is Braille?

All over the world, persons with visual handicaps have used Braille as the

primary means to reading information. Also, the concept of Braille has been

accepted as a universal approach that works across the boundaries of the world.

Different countries of the world have adapted the system of Braille to suit their

languages. Irrespective of these changes or modifications, Visually Handicapped

persons understand standard Braille for the Roman alphabet (English Braille)

making it possible to exchange information in a consistent fashion across different

countries.

Brief introduction to Braille

Standard Braille is an approach to creating documents which could be

read through touch. This is accomplished through the concept of a Braille cell

consisting of raised dots on thick sheet of paper. The protrusion of the dot is

achieved through a process of embossing.


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A cell consists of six dots arranged in the form of a rectangular grid of two

dots horizontally and three dots vertically. With six dots arranged this way, one

can obtain sixty three different patterns of dots. A visually Handicapped person is

taught Braille by training him or her in discerning the cells by touch, accomplished

through his or her fingertips. The image below shows how this is done.

Each arrangement of dots is known as a cell and will consists of at least one

raised dot and a maximum of six. The image shown above is an example of

embossed Braille cells. On a Braille sheet, the dots are created by embossing using

a special printer or even a manual machine that simultaneously embosses the dots.

Today, we also have Braille printers which may be connected to computers on

standard printed interfaces. These are generally known as Braille Embossers.

In the developed world, Visually Handicapped persons are taught to read

Braille at a very early age. They develop reading skills well enough to read the

text books and reference material and attend schools, often with normal children,

to get integrated into the mainstream of life.

At this point one might ask "does Braille have the functionality of the

printed medium?". The answer is surprisingly yes, and in schools for the Visually

Handicapped, the libraries will be full of Braille text and reference books. It is true

that Braille books are bulky and cannot be carried around just as easily as printed

books but the point to keep in mind is that we have to provide a suitable medium

for the Visually Handicapped that will enable them to get educated in the first

place. So providing them a resource, which could be bulky but which will allow

them to read is important.

The Braille Cell

A printed sheet of Braille normally contains upwards of twenty five rows of

text with forty cells in each row. The physical dimensions of a standard Braille

sheet are approximately 11 inches by 11 inches. The dimensions of the Braille cell

are also standardized but these may vary slightly depending on the country.


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The dimensions of a Braille cell, as printed on an embosser is shown below.

The six dots forming the cell permit sixty three different patterns of dot

arrangements. Strictly, it is sixty four patterns but the last one is a cell without

any dots and thus serves the purpose of a space. A Braille cell is thus an equivalent

of a six bit character code, if we view it in the light of text representation in a

computer! However, it is not related to any character code in use with computers.

Standard English Braille

In Standard English Braille, many of the sixty three cells will correspond

to a letter of the Roman alphabet, or a punctuation mark. A few cells will

represent short words or syllables that are frequently encountered in English. This

is done so that the number of cells required to show sentence may be reduced,

which helps minimize the space requirements while printing Braille. These special

cells are used in specific ways along with regular cells to form sequences which are

known as contractions. Contractions are specified for most frequently used

syllables and words and there is a standard list of contractions in English Braille.

To begin with, one is taught Braille without contractions and this is called Grade-1

Braille. Braille with contractions is known as Grade-2 Braille.


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In standard Grade-1 Braille, the twenty six letters, and some punctuation

marks are used. No distinction is made between upper case and lower case

letters. Interestingly, numerals are not included in the set of symbols which have

been assigned cells. Shown below is the table that corresponds to Grade-1 Braille.

In the above figure, only thirty six of the sixty three cells are shown. The

rectangular border around the cell has been added to make it easier for the reader

to identify the dots correctly.


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BLOCK DIAGRAM AND ITS DESCRIPTION

BRAILLE SENSOR:

In this project we use 6 push buttons in a 2x3 matrix. When the buttons are

pressed against the Braille, the buttons corresponding to the bumps on the Braille

will be pushed.

The push button design not only makes our project more simple and

elegant, it also makes it more affordable to the blind people.

Since our product is targeted to blind people who didn t master the Braille

reading, we assumed they are new to the blind walking stick as well. Therefore,

we attached an IR sensor to detect whether there is any object close to the user,

in hope to reduce the chance of any unfortunate collisions.

The horizontal and vertical spacing between dot centers within a Braille cell

is approximately 0.1 inches (2.5 mm); the blank space between dots on adjacent

cells is approximately 0.15 inches (3.75 mm) horizontally and 0.2 inches (5.0 mm)

vertically.

MICROCONTROLLER (8051):

This project uses an 8 bit microcontroller which receives the binary data

input from the switches and it decodes the input and according to the key pressed

it identifies the letter now the allophones of the letter which is already stored in


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the microcontroller is sent to the Speakjet serially. The microcontroller is

programmed using the C code.

SPEAKJET:

The SpeakJet is a completely self-contained, single-chip voice and complex

sound synthesizer. It uses a mathematical sound algorithm to control an internal

five channel sound synthesizer to generate on-the-fly, unlimited vocabulary speech

synthesis and complex sounds.

The SpeakJet is pre-configured with 72 speech elements (allophones), 43

sound effects, and 12 DTMF Touch Tones. Through the selection of these sounds,

and in combination with the control of the pitch, rate, bend, and volumeparameters, the user has the ability to produce unlimited phrases and sound

effects, with thousands of variations, at any time.

The SpeakJet can be controlled simultaneously by logic changes on any one

of its eight Event Input lines, and by a single I/O serial line, allowing for both CPU-

controlled and stand-along operations.

HEADPHONE:

The output of the Speakjet is an electrical signal which can be converted

into sound signal with the help of a transducer i.e. nothing but the headphone.

WORKING:

When the Blind Aid is made ON we receive a sound of Starting now it can

be used to read the Braille letters which can be done by pressing the keys present

on the Braille sensor and depending upon the position of the key press the

corresponding letter can be identified which is processed by the microcontroller

once the letter is identified the letter can be outputted in the form of voice which

can be done using the Speakjet IC which receives the signals from the

microcontroller.

It also has an obstacle detection sensor which when obstructed will produce

a sound providing the information regarding the presence of an obstacle thus it

helps to avoid collision.


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Advantages:

It is portable. It is affordable. Helps in easy learning of Braille Language Warns the user if there is any obstacle in front of him.

Bibliography

www.cornell.edu

www.wikipedia.org

www.sparkfun.com
http://www.cornell.edu/http://www.wikipedia.org/http://www.wikipedia.org/http://www.cornell.edu/

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