Braille Learning System using Raspberry Pi

Inhalt

LIST OF FIGURES

LIST OF TABLES

CHAPTER 1
1.1 BLOCK DIAGRAM
1.2 ABOUT BARILLE
1.3 BRAILLE STRUCTURE
1.4 IMPORTANCE OF BRAILLE
1.5 BRAILLE IN DAY TO DAY LIFE
1.6 BRAILLE SYMBOLS
1.6.1 THE BRAILLE ALPHABET

CHAPTER 2 LITERATURE SURVEY

CHAPTER 3 HARDWARE DESCRIPTION
3.1 Raspberry Pi 3 Model B
3.1.1 PINDIAGRAM
3.2 SOLENOID ACTUATOR
3.3 TRANSISTOR TIP122
3.4 DIODE 1N4007
3.5 RESISTOR 1K

CHAPTER 4 POWER SUPPLY DESCRPITION
4.1 7812 REGULATOR
4.2 CAPACITOR 470uF
4.3 TRANSFORMER
4.4 REGULATED POWER SUPPLY WORKING
4.4.1 THE POSITIVE HALF-CYCLE
4.4.2 THE NEGATIVE HALF-CYCLE

CHAPTER 5
5.1 CIRCUIT DIAGRAM OF CONTROL UNIT
5.2 CIRCUIT EXPLANATION
5.2.1 OPEN CIRCUIT CONDITION OF SOLENOID ACTUATOR
5.2.2 CLOSED CIRCUIT CONDITION OF SOLENOID ACTUATOR
5.3 CIRCUIT DIAGRAM OF POWER SUPPLY
5.3.1 IC 7812
5.3.2 CAPACITOR

CHAPTER 6 TEXT TO VOICE SYTHESIS
6.1 INTRODUCTION
6.2 SOFTWARE PACKAGES
6.2.1 FESTIVAL
6.2 2 FLITE
6.2.3 Espeak
6.3 AUDIO CONFIGURATION
6.3.1 DESKTOP VOLUME CONTROL
6.3.2 COMMAND LINE
6.3.3 RASPI-CONFIG
6.4INSTALLATION FLITE PACKAGAE

CHAPTER 7 TECHNICAL CHANLLENGES ENCOUNTERED DURING THE BRAILLE SYSTEM DESIGN
7.1 POWER SUPPLY DESIGN
7.2 BRAILLE CHARACTER SIZE
7.3 ADVANTAGES OF THE BRAILLE KIT

CONCLUSION

APPENDIX

REFERENCE

LIST OF FIGURES

FIGURE NO NAME OF FIGRES PAGE NO

1.1 Block diagram of the proposed system

1.2 Arrangement of Braille cell

1.3 Braille in Rubik’s cube

1.4 Braille in ATM keypad

3.1 Raspberry pi 3 processor

3.2 Pin diagram of Raspberry pi

3.3 Technical Parts of Raspberry pi 3

3.4 Solenoid actuator

3.5 Internal view of solenoid actuator

3.6 Transistor TIP122

3.7 Symbol of Transistor

3.8 Diode 1N4007

3.9 Resistor 1K

4.1 Pin diagram of 7812 regulator

4.2 Capacitor 470uF

4.3 Transformer 220V AC to 24V AC

4.4 Power supply block diagram

4.5 Full wave bridge rectifier

4.6 Positive half cycle of full wave bridge rectifier

4.7 Negative half cycle of full wave bridge rectifier

5.1 Circuit Diagram of Braille system

5.2 Solenoid de-energized during OFF condition

5.3 Solenoid energized during ON condition

5.4 Circuit diagram of power supply

7.1 Arrangement of Braille cell for smaller size

LIST OF TABLES

TABLE NO NAME OF THE TABLE PAGE NO

1.6.1 The Braille cell arrangement for alphabet

1.6.2 The Braillecell arrangementnumbers

1.6.3 The Braillecell arrangement punctuation

3.3.1 Characteristics of Transistor TIP122

ABSTRACT

Braille literacy is crucial for blind individuals, as it enables life-long learning and is key to employment and independency. One way to promote Braille literacy is to make existing Braille reading devices more accessible, affordable, and user friendly. Commercially available Braille reading devices in this regard need various improvements. Most of these devices cost thousands of dollars, mainly because they rely on multiple piezoelectric actuators in order to create the Braille letters. Other issues include high voltage actuation and reduced portability. In order to solve these issues and improve existing Braille displays, various actuation methods have been widely investigated.285 million people are estimated to be visually impaired worldwide, 39 million are blind and 246 have low vision. India has the largest population of blind people in the world. That's over 12 million people. Even the central and state government provide job opportunities for blind and visually impaired people. But only few vacancies are filled due to lack of education. Lack of education for blind people is due to the lack of qualified teachers to teach them Braille. Learning the Braille script is not an easy task for Visually Impaired students. Visually Impaired students have to memorize various patterns of keys of Braille matrix assigned for different letters/words/symbols in Braille script to read and write effectively. This project helps in simplifying the process of learning of braille instructions. The integration of physical activity and hearing can facilitate easy learning of Braille Script. In this project we develop a kit which helps the blind and visually impaired people to learn braille even in the absence of teachers.

CHAPTER 1 INTRODUCTION

1.1 BLOCK DIAGRAM

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Fig 1.1 Block diagram of the Proposed system

The raspberry pi is coded in python. Accordingly the raspberry pi produces the output and its output signal is sent to the solenoid actuator which acts as the braille display. The corresponding audio output is taken from the raspberry pi and it is heard in the headphone.

1.2 ABOUT BARILLE

Braille is named after its creator, Frenchman Louis Braille, who lost his eyesight due to a childhood accident. Braille was invented in 1824, the simple dot system is still considered by many people as the best reading system for blind people. It is a brilliant tool for communicating and participating in society. Braille is a tactile writing system used by people who are blind or visually impaired. It is traditionally written with embossed paper. Braille is a system of raised dots that can be read with the fingers by people who are blind or who havelow vision. Braille is not a language. It is a code by which all languages can be written and read. Through the use of Braille, people who are blind are able to review and study the written other word. It provides a passport for literacy and gives an individual the ability to become familiar with spelling, punctuation, paragraphing and formatting considerations.

1.3 BRAILLE STRUCTURE

Braille symbols are formed within units of space known as Braille cells. A full Braille cell consists of six raised dots arranged in two parallel vertical columns of three dots (like the number 6 on a dice). The dot positions are identified by numbers one through to six. 63 combinations are possible using one or more of these six dots. Cells can be used to represent a letter of the alphabet, number, punctuation, part of a word or even a whole word.

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Fig 1.2 Arrangement of Braille cell

1.4 IMPORTANCE OF BRAILLE

The expectations for students to learn to read and to write is no different for a sighted or blind person; it is fundamental skill that everyone should develop in order to excel in their life. There is no substitute for the ability to read. For blind people, braille is an essential tool that helps in the process of becoming literate. Tape recorders and synthesized speech are useful tools, but they are inadequate substitutes for reading and writing. Braille plays an important role in education of blind and visually impaired people. Several studies show that braille literacy is directly related with academic achievement and employment among the blind and visually impaired. There are many government job available for blind and visually impaired people. They must be educated to get job from the government organisation. For that they must learn braille which is an important thing. When blind children learn Braille, they learn grammar, spelling, punctuation and sentence structure skills that they do not learn using text-to-speech technology. Braille also lets blind people read charts and graphs that are almost impossible to convey using text-to-speech. Even if they also use low-vision aids or text-to-speech technology, Braille lets them label items clearly, read public signs at airports or bathrooms.

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Fig 1.3 Braille in Rubik’s cube

1.5 BRAILLE IN DAY TO DAY LIFE

A person who reads braille can roam independently among the community as braille increasingly is showing up everywhere. With the Convention on the Rights of Persons with Disabilities implemented in 2008, since then over 150 countries have signed the ratification. The declaration has introduced the recognition of persons with disabilities on an equal basis with others worldwide. Additionally, society is beginning to recognize the need to present equality for all citizens within its communities. Therefore, public spaces continue to present tools and aids for all disabilities. Braille is used in everyday communication and as a literate blind or visually impaired individual, independence is given. Blind individuals deserve this chance at equality, and this is something that braille provides. Speech feedback or other digital tools are no compensation for braille. Listening alone is not enough. To read without braille, a person who is blind is entirely dependent on computers with voice synthesizers or audio recording, neither of which is useful in every circumstance. Braille brings sight to the visually impaired and blind.

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Fig 1.4 Braille in ATM keypad

1.6 BRAILLE SYMBOLS

The basic braille alphabet, braille numbers, braille punctuation and special symbols characters are constructed from six dots. These braille dots are positioned like the figure six on a die, in a grid of two parallel vertical lines of three dots each. From the six dots that make up the basic grid, 64 different configurations can be created.

1.6.1 THE BRAILLE ALPHABET

Table no 1.6.1 Braille cell arrangement for alphabets

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1.6.2 THE BRAILLE NUMBERS

Braille numbers are formed by placing a braille number sign before braille letters. They are internationally accepted braille system.

Table no 1.6.2 Braille cell arrangement for numbers

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1.6.3 THE BRAILLE PUNCTUATION

These are the common punctuation used in our day to day life. These braille combinations for punctuations are accepted internationally.

Table no 1.6.3 Braille cell arrangement for punctuations

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CHAPTER 2 LITERATURE SURVEY

Saurabh Bisht,Sandeep Reddy Goluguri,Rajat Maheshwari,Akhilesh Kumar and P.Sathya[1]

The aim of this project is to create a refreshable electronic braille display using Raspberry Pi 2 and Arduino Mega2560 board. This aims at creating a refreshable braille display that is capable of converting Normal text file as well as printed image files to braille. To achieve the functionality of converting image files to text we have used tesseract-ocr engine of Google which the best available OCR engine available right now and is highly accurate. The Raspberry pi does the image processing and the Arduino drives the display. The display is made of 6 servo motors, which can be controlled by the PWM. The servo motor acts as an actuator in this project.

Prachi Rajarapollu, Stavan Kodolikar, Dhananjay Laghate, Amarsinh Khavale[2]

Blind people are an integral part of the society. However, their disabilities have made them to have less access to computers, the Internet, and high quality educational software than the people with clear vision. Consequently, they have not been able to improve on their own knowledge, and have significant influence and impact on the economic, commercial, and educational ventures in the society. One way to narrow this widening gap and see a reversal of this trend is to develop a system, within their economic reach, and which will empower them to communicate freely and widely using the Internet or any other information infrastructure. Over time, the Braille system has been used by the visually impaired for communication and contact with the outside world. This paper presents the implementation of Braille to Text/Speech Converter on FPGA Spartan3 kit. The actual Braille language is converted into English language in normal domain. The input is given through braille keypad which consists of different combinations of cells. This input goes to the FPGA Spartan3 Kit. According to the combinations given, FPGA converts the input into corresponding english text through the decoding logic in VHDL language. After decoding, the corresponding alphabet is converted to speech through algorithm. Also it is displayed on the LCD by interfacing the LCD to the Spartan3 kit.

Aisha Mousa, Hazem Hiary, Raja Alomari, and Loai Alnemer [3]

Firsthand Experiences with a Balanced Approach to Literacy , new from the American Foundation for the Blind, begins with a discussion of the whole language and traditional approaches to teaching reading and writing. Author Anna M. Swenson is a Braille teacher who favors the whole language philosophy, but who has taught in various settings, and includes ideas and techniques that will work with the traditional approach as well. The books focus is on creating an atmosphere that promotes literacy, no matter what the teaching approach.According to Swenson, Braille teachers, who are the book primary intended audience, are not only teaching the Braille code, but are also teaching reading and writing. Swenson encourages Braille teachers to keep up to date with current approaches to teaching language arts, to get samples of sighted students work in order to understand the level of classroom expectation, and to consult with the reading specialist or learning disabilities specialist in the school if the blind student seems to be having difficulty learning to read.Swenson makes detailed suggestions regarding working out the technical aspects of teaching Braille to a student in the mainstream, especially in a whole language classroom. In the section A Morning in the Mainstream, the reader can get a vivid view of how the Braille teacher can work alongside the classroom teacher to ensure a solid foundation for the blind student.

Vineeth Kartha; Dheeraj S. Nair; S. Sreekant; P. Pranoy; P. Jayaprakash[4]

Braille is a textile document which is most common means of reading for visually challenged people. There is a significant need to preserve old Braille documents and literatures. Hard-copy Braille is heavy, bulky, which takes considerable space to store and maintain. The materials that are available only in hard copy bear a threat of losing them. The Automation of Braille reading and digitization process will help in preserving, distributing Braille over network and reproducing hard copy only on demands. The need for digitizing Braille has lead many researchers in improvising and implementation of optical Braille recognition systems. A survey and comparative study on various algorithms and techniques proposed and presented by researchers in improvising Optical Braille Recognition system to effectively/efficiently translate Braille to text has been presented in this paper.

CHAPTER 3 HARDWARE DESCRIPTION

3.1 Raspberry Pi 3 Model B

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Fig 3.1 Raspberry pi 3 processor

The Raspberry Pi 3 is the third generation Raspberry Pi. It is a series of small single board computers developed in the United Kingdom by the Raspberry foundation to promote the teaching of basic computer science in schools and in developing countries. It builds upon the features of its predecessors with a new, faster processor on board to increase its speed. The Raspberry Pi hardware has evolved through several versions that feature variations in memory capacity and peripheral-device support. It has an identical form factor to the previous Pi 2 and has complete compatibility with Pi 1 and 2.

3.1.1 PINDIAGRAM

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Fig 3.2 Pindiagram of Raspberry pi

The Raspberry Pi may be operated with any generic The Broadcom BCM2835 SoC used in the first generation Raspberry Pi is somewhat equivalent to the chip used in first generation Smartphone’s (its CPU is an older ARMv6 architecture), which includes a 700 MHz ARM1176JZF-S processor, Video Core IV graphics processing unit (GPU), and RAM. It has a level 1 (L1) cache of 16 KB and a level 2 (L2) caches of 128 KB. The level 2 cache is used primarily by the GPU. The SoC is stacked underneath the RAM chip, so only its edge is visible.The current Model B boardsincorporate four USB ports for connecting peripherals like computer, keyboard and mouse.It may also be used with USB storage, USB to MIDI converters, and virtually any other device/component with USB capabilities.Other peripherals can be attached through the various pins and connectors on the surface of the Raspberry Pi. Raspberry pi can be used with varoius operating system. There are linux based and non linux based oprating system. The mainly used operatind system is Raspian.

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