Low Cost Wireless Electronic Braille Reader

Abstract

Electronic Braille readers are getting popular worldwide day by day among the visually disabled people. Bangladesh has over half a million blind people and due to the high cost of the available Electronic Braille in the market, most of these people are unable to take advantage of this technology. To make proper use of this technology, a Servo motor based wireless electronic braille was designed. Currently available servo motor based and piezoelectric based braille have some issues with their mechanical features and price respectively. This paper is about the design and construction of a Wireless Electronic Braille Device with resolved mechanical functionality, wireless data transfer availability and much lower cost than available electronic braille of this type. The proposed design ensures correct mechanical functionality, accuracy, security, faster data transfer and lower cost.

Full text

American Academic & Scholarly Research Journal Vol. 7, No. 6, Sept 2015
www.aasrc.org/aasrj
95
Low Cost Wireless Electronic Braille Reader
Syed Razwanul Haque,a Miah Md. Asaduzzamanb, Robi Kormokar,c
Akhlak Uz Zaman Ashik,d Maruf Hossain Rahat,e Pronab Karmakar f
aLecturer, Dept. of Electrical and Electronic Engineering, Metropolitan University,
Sylhet, Bangladesh, razwan@metrouni.edu.bd,
bAssistant Professor, Dept. of Electrical and Electronic Engineering,, Metropolitan University,
Sylhet, Bangladesh, mzaman@metrouni.edu.bd
cDept. of Physics, Shahjalal University of Science and Technology,
Sylhet, Bangladesh, robikormokarsust123@gmail.com
dDept. of Computer Science and Engineering, MetropolitanUniversity,
Sylhet, Bangladesh, akhlak.ashik@gmail.com
eDept. of Physics, Shahjalal University of Science and Technology,
Sylhet, Bangladesh, sustianrahat@gmail.com
fDept. of Computer Science and Engineering, MetropolitanUniversity,
Sylhet, Bangladesh, cse.pronab@gmail.com
Abstract. Electronic Braille readers are getting popular worldwide day by day among the visually disabled
people. Bangladesh has over half a million blind people and due to the high cost of the available Electronic
Braille in the market, most of these people are unable to take advantage of this technology. To make proper use
of this technology, a Servo motor based wireless electronic braille was designed. Currently available servo
motor based and piezoelectric based braille have some issues with their mechanical features and price
respectively. This paper is about the design and construction of a Wireless Electronic Braille Device with
resolved mechanical functionality, wireless data transfer availability and much lower cost than available
electronic braille of this type. The proposed design ensures correct mechanical functionality, accuracy, security,
faster data transfer and lower cost.
Keywords: Wireless, E-Braille, Low cost, Apps, Servo motor
1 INTRODUCTION
Braille is a tactile writing language of raised dots, mainly used by the blind and visually impaired. It is
developed for our hap-tics perception, a combination of the sense of touch, movement and finger pressure.
The dots are arranged in cells. Every cell consists of a majority of six dots in a small rectangle. A finger tip can
feel the whole cell at once. The system gives 63 combinations and one blank step. In six dots Braille, each cell
consists of a 3x2 matrix of raised dots. Each cell is made up of six raised dots that relate to a letter, number or
character. These dots are raised roughly 0.9mm by pressure from a cylindrical pin, causing identification
underneath the thick paper. The existing system lacks portability with insufficient power management. The
visually impaired do not have access
to e-documents and SMS without
through knowledge and training to
how to use the device with simplicity
of operation.
Fig. 1. Real device view

American Academic & Scholarly Research Journal Vol. 7, No. 6, Sept 2015
www.aasrc.org/aasrj
96
Current systems available are based on Stepper motors, Servo motors and Piezoelectric crystals. Stepper motor
based E-Braille has power issues whereas Piezoelectric crystal based E-Braille is very costly. On the other hand,
current Servo motor based Braille does not have precise cell dimension and also suffers from initial mechanical
placement error[1].
In this proposed electronic Braille system, the main objective is to eliminate the barriers that the currently
available Servo motor based E-Braille suffers from and make it available within a reasonable price to the
visually challenged children and adults who are deprived from using the embedded -tech device due to their lack
of knowledge to use computers. The system is designed in such a way so that they can reach the e-documents
with ease and also can compose short message text for sending it to the computer.
The proposed device is developed by using embedded technology with peripheral communication, wireless
transceiver, Bluetooth module, rechargeable and portable batteries etc. In our proposed system, the device
possesses a microSD socket for accessing stored eBooks and also has an interface for browsing them. The
device can also interface with mobile phones via Bluetooth and a costumed application can capture SMS for
display in Braille, can adjust the height of the pin size and can also adjust the refreshing rate of the text. The
battery backup is reasonable with a tested 5 hours of uninterrupted power supply.
Fig. 2. Internal servo placement
2 DESIGN ARCHITECTURE
Architecture of the device can be analyzed on two platforms, Hardware and Software. The device contains
mainly four parts. First part is the bluetooth transceiver which is responsible for the wireless data transferring.
Second is the microcontroller which is interfaced with bluetooth and the third part which is the servo system
containing 6 servo motors. The fourth part of the hardware is the Power control circuit which is connected with
the servo system to limit the peak current. Here, the microcontroller is compatible with the Arduino Software
libraries.
The boards functions as:
a) To produce Braille text, the microcontroller receives text from the removable memory or the wireless
transceiver
b) Send them to the control board via serial interface.
c) The microcontroller then convert the ASCII characters into Braille symbol and then equivalent servo control
signals to actuate the Braille pins.
d) There is another input part with six input buttons arranged like Braille text which can be used to send Braille
text signal to the microcontroller and the controller generates equivalent ASCII character and can send it to the
corresponding bluetooth device.

American Academic & Scholarly Research Journal Vol. 7, No. 6, Sept 2015
www.aasrc.org/aasrj
97
Fig. 3. The overview of the built Braille System.
3 HARDWARE ARCHITECTURE
The hardware design consists of six parts. Each of the parts has separate functions. They are given in the
following sections.
3.1 BRAILLE INTERFACE
Braille Interface consists of a plate on top of two stacks of six
servos. Each servo is responsible for lowering and raising a pin, which will emerge through perforations on the
top plate to form a Braille dot. The perforations serve as guides for the
pins, restricting their motion along the vertical axis and together they form two six-dot Braille cells which users
will touch[2]. Micro servos are chosen for their lower price and the ability to maintain their positions when no
power is supplied.
This reduces power consumption as compared to mechanisms where power is required to maintain the state of
the Braille dots at all times[3]. Figure-2 shows the dimension of the Braille interface.
Fig. 4. Braille interface dimension

American Academic & Scholarly Research Journal Vol. 7, No. 6, Sept 2015
www.aasrc.org/aasrj
98
3.2 REMOVABLE MEMORY
The purpose of a removable memory in this design is to store e-books. A micro-SD card will be used as
removable memory. A microSD card is one of the smallest flash memory cards on the market today. Here SD
stands for Secure Digital. Secure Digital or (SD) is a non-volatile memory card format for use in portable
devices, such as mobile phones, digital camera, GPS navigation system etc. Most technical measurements for
the microSD card put it at 15x11x1. It is interfaced to the controller by SPI protocol, which is supported by the
ATMEGA328 of the controller.
3.3 WIRELESS BLUETOOTH
The purpose of a wireless receiver in this design is to send and receive data from a mobile device. The
Bluetooth communication protocol was chosen since mobile devices can communicate wirelessly to close range
peripherals via Bluetooth.
3.4 CONTROLLER
Atmega328 is a AVR microcontroller that is developed by Atmel corporation. AVR is an 8-bit microcontroller
belonging to the family of reduced instruction set computing(RISC).In RISC architecture the instruction set of
the computer are not only fewer in number but also simpler and faster in operation compared to CISC
architecture. The AVR core combines a rich instruction set with 32 general purpose working registers. All the32
registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be
accessed in one single instruction executed in one clock cycle. The resulting architecture is more code efficient
while achieving throughputs up to ten times faster than conventional CISC microcontrollers[4].
3.5 POWER SUPPLY
The power module consists of two 3.3V 1A voltage regulators, one 3.3V 500mA voltage regulator, a fuel
gauging IC and a two-cell 7.4V rechargeable lithium-polymer battery (LiPo). The device is designed such that
all modules are powered at 3.3V. This is because communication with the microSD card utilizes the SPI
interface, which operates only at 3.3V while all other modules have a wider operating voltage range inclusive of
3.3V. If a different supply voltage is used, we would have to up and down-convert the voltage of the data
signals on the SPI interface. Each one of the two 1A voltage regulators is responsible for powering six servos,
while the 500mA voltage regulator is responsible for powering all the other modules[5].
4 PROGRAMMING IDE
In the proposed system ATMEGA microcontroller has been used as this supports Arduino platform which is the
efficient IDE tool uses simplified library functions of C/C++. It is inexpensive and can support windows, Mac
OS x and Linux. It makes input/output operations much easier. Arduino is a open-source single-board
microcontroller, descendant of the open-source Wiring platform, designed to make the process of using
electronics in multidisciplinary projects more
accessible[6].
The Arduino IDE is a cross-platform application written in Java, and is derived from the IDE for the Processing
programming language and the Wiring project. It refers to an open-source electronics platform or board and the
software used to program it. In essence, this platform provides a way to build and program electronic
components. Arduino programming language is a simplified form of C/C++ programming language based on
what Arduino calls "sketches," which use basic programming structures, variables and functions. These are then
converted into a C++ program. Other open-source electronics prototyping projects, such as Wiring and
Processing, provide the underpinnings for Arduino technology[4].

American Academic & Scholarly Research Journal Vol. 7, No. 6, Sept 2015
www.aasrc.org/aasrj
99
4.1 COORDINATION OF FRAMEWORK
4.1.1 Initialization
 Library initialization: Here servo.h library is needed to be included to operate servo motors.
 Variable Initialization: An array of six servo motor variables provided with servo.h library and few
global variables have been initialized according to device requirement.
4.1.2 Void Setup
Step 1(Ready Device): This function comes first time when the device is switched on and runs for one
time only.
 Hardware Serial Communication baud rate(9600) is fixed here and microcontroller establishes
serial communicates over bluetooth device.
 Microcontroller arms and ensures initial position of rotation of all these six servos by giving
specific rotation value.
 Then goes to Step 2.
4.1.2 Void Loop
Step 2(Mood Selection): This step fixes device mode such as send, receive and end mood.
 If send mode is selected then goes to step 3.
 If receive mode is selected then it goes to step 4.
 Otherwise goes to step 5.
Step 3(Send Mode): Enables braille input buttons, decodes them into ANSII character and sends them
into smartphone via bluetooth.
 Microcontroller reads all the braille input buttons dedicatedly in this step
 Takes input in braille format
 If user press send button then microcontroller decodes braille input into ANSII character and
send this via serial communication over bluetooth
 If user press cancel button then microcontroller considers this entry as wrong or unnecessary
and does not decode to send
 User must to press send button to send every individual character
 After pressing send or cancel button, it goes to step 3 to check device mode
 This job will be continued until user change the device mood and microcontroller will often
check device mood at the time of operation
Step 4(Receive Mode): Disables braille input buttons, receives and presents incoming data in braille
format.
 In this step microcontroller disables input button and only concentrates into receiving ANSII
characters from smartphone via serial communication over bluetooth
 Encodes this ANSII character into braille system
 Fixes which servo will pull up their pins or which will not
 After every character representation, goes to step 3 to check device mode.
Step 5(End mood): Denotes whether user wants to go to the standby or sleep mode
 Device does not give any power to bluetooth module or servo motors and does not take any
input from any button without mode selection button

American Academic & Scholarly Research Journal Vol. 7, No. 6, Sept 2015
www.aasrc.org/aasrj
100
Fig. 5. Overall system flowchart
5. HARDWARE MANAGEMENT
5.1 SERVO DISPLACEMENT CONTROL
A severe mechanical problem arises when the servo system gets the initial power. Any servo system ends up in
an ambiguous position when initial power is supplied. If this happens in a Servo based Braille system, the
Braille touchpad pins will be disoriented. But this problem is solved by fetching power from the microcontroller
to the servo system rather than fetching power directly from the power supply. After turning on the device, the
microcontroller is started first and then its MCU firmware starts servo signal from a pre-calibrated value. After
ensuring proper and pre-calibrated servo signal, the Microcontroller provides signal to a relay which is
connected with servo main power supply. As soon as the servo starts, it has no chance to move back to any
ambiguous position because calibrated servo signal has already started before the servo is switched on. Figure-2
shows the actual dimension of a Braille where the horizontal pin to pin distance is 3.7mm and vertical pin to pin
distance is 2.5mm. The required dot height of a Braille is 0.019” and refresh rate is at least 7.5 characters/s[7].
To make the Braille device user friendly, above mentioned actual dimension is maintained and to make it more
user friendly the refresh rate (gaping time), character staying time and pin height are kept adjustable so that the
user can adjust those according to his/her comfort level.

American Academic & Scholarly Research Journal Vol. 7, No. 6, Sept 2015
www.aasrc.org/aasrj
101
5.2 POWER MANAGEMENT
In this device LM2596S power module is used As a power regulator. It was found that it starts operation from
input voltage as low as 2.58V and for 2.58V input, output is 2.55V. This allows to use large input voltage range.
So two lithium cell in series can provide enough voltage. Both batteries are set to discharge as low as 2.7V
(2.7+2.7V=5.4V). We can use various types of batteries. The device running time can be enhanced up to 5 hours
by using Panasonic NCR18650B battery[8].
The Braille interface requires 300mA to 1300mA (1.5watt to 6.5watt) depending on which characters are being
displayed. When more pins rise up, the device consumes more power. Although digital servo is faster than
analogue servo but digital servo is power hungry and costly[9]. The required response time and precision level
is comfortably achievable by using of analogue servo system. The braille head pins are directly mounted to
servo without using any extra mechanical gear which makes it less power hungry and adequate responsive. It
also makes it simple and less noisy[10].
6. RESULT
The device has been tested several times with the help of some visually impaired people of Narsingdi,
Bangladesh. The device performed perfectly and it was up to their satisfactory level.
Fig. 6. Testing by visually impaired persons
7. CONCLUSION
The messages and e-text in ASCII form can be converted successfully into Braille text with this low cost
Wireless Electronic Braille Reader and hence we can conclude that the blind can get a chance to access and
utilize the e-doc and web resources with ease and simplicity. The designed portable device is powered up by
rechargeable lithium polymer battery and executed on open source powerful software environment It is easy to
handle by the visually impaired users with their abilities.
Future work in this field can be done by adding a facility to read data from Flash drives, enabling voice
command function and to add a GSM module for providing texting service for the visually impaired. This
would make the system more easy to handle and provide step by step instructions to access the internet and
extract the technology to the maximum limit.
Acknowledgements
Testing of the Low Cost Wireless Electronic Braille would not be possible without the help and cooperation of
the visually impaired people of Narsingdi, Bangladesh. A video of the device being tested by some visually
impaired people is available on our youtube channel in the following web link.
https://www.youtube.com/Nabilphysics

American Academic & Scholarly Research Journal Vol. 7, No. 6, Sept 2015
www.aasrc.org/aasrj
102
References
Firoozian, Riazollah , Servo Motors and Industrial Control Theory,
Springer, 2014nada
Yasuhiko Dote, Servo Motor and Motion Control: Using Digital Signal Processors/Book and Disk, Prentice
Hall and Texas Instruments Digital Signal Processing Series
Michael Margolis, Arduino Cookbook, Second Edition, O’Reilly publishers.Research Laboratory (ePEARL),
Queen’s University, Ca
Massimo Banzi, Getting Started with Arduino,
Second Edition, O’Reilly publishers
Portable Refreshable E-Braille, M.A.Raja, A .Arunya, Dipti Yadav, G.Kanitha, R.Maheshwari / International
Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com
Vol. 3, Issue 1, January -February 2013, pp.1393-1397
Kumar J.A.V, Visu A , Raj M.S, Prabhu M.T, Kalaiselvi V.K.G,
A pragmatic approach to aid visually impaired people in reading, visualizing and understanding textual
contents with an automatic electronic pen „Computer Science Automation Engineering (CSAE), 2011
IEEE International Conference.
http://www.pharmabraille.com/pharmaceutical-braille/the-braille-alphabet/
https://www.arduino.cc/en/Reference/Servo
http://wiki.mikrokopter.de/en/HC-06
http://www.banglabraille.org
https://www.youtube.com/Nabilphysics
View publication statsView publication stats