b raille d isplay katie and kara chylinski advisor: professor hedrick march 5, 2005

BRAILLE DISPLAY

Katie and Kara Chylinski

Advisor: Professor Hedrick

March 5, 2005

OUTLINE

• Background

• The Problem

• Our Objective

• Design Process

• Final Design

• Results

• Conclusion

INTRODUCTION

Braille Alphabet Braille Display

MOTIVATIONS

• Combine past class work

• Include a variety of topics

• Solve a problem

• Beneficial to people with disabilities

• Have fun!

PROJECT GOAL

Concerns: inexpensive, adaptable, portable

SYSTEM MODULES

Convert printed page to bitmap

Convert bitmap to ASCII characters

Change ASCII to Braille dot pattern

Send dot pattern to display unit

MODULE DESIGN PROCESS

• Environment: Linux

• Collecting bitmap: SANE

• Converting bitmap: GOCR

• Driver hardware: Cynagal C8051 Microcontroller

This module technique allows us to change each component.

DEVELOPMENT SYSTEM

Scanner

Power Supply

DisplayCell

Circuit

Program

MicrocontrollerC++ Program

Text

DESIGN PROCESS• Research• Compare actuators• Design sketches and performance criteria• Configure scanner and optical character

recognition (OCR)• Use microcontroller and RS232 port• Program code changing ASCII to Braille• Construct driver circuit

RESEARCH

• Freedom Scientific

• Pulse Data

• ALVA

• Metec

ACTUATORS

Solenoids Piezoelectric Speakers

Cost + - ++Size + ++ -

Voltage - + ++

PERFOMANCE CRITERIA

• Cell Dimensions:• Between dots: 2.54 mm

• Dot height: .5 mm

• Between cells: 3.75 mm

• Changing speed

SOLIDWORKS SKETCH

DETAILED SKETCH

SCANNER AND OCR

• Devices– Epson SCANNER GT-8500– GOCR 0.39

• Procedure– Scan in Text– Use Optical Character Recognition– Create “out.txt” File

MICROCONTROLLER

• RS232 Port

• Serial Port

• Data Communication

Protocol

• Program

SEND@

WAITR

SENDCHAR

WAITS

WAIT

WAIT@

SENDR

WAITCHAR

SENDS

Linux Microcontroller

@

R

char

S

PROGRAM

   // receive example: // a '1' turns LED on; a '0‘ turns LED off.

   P2MDOUT = 0xff;   XBR2 = 0x40;     P2 = 0x00;

   while (1) {      input_char = _getkey();          if (input_char == '@') {              putchar('R');                 //get the braille character                 input_char = _getkey();                 putchar('S');                 P2 = input_char;       }     }

C++ PROGRAM

• Algorithm

• Set baud rate

• Open output file from scanner

• Read in first character

• Communicate with microcontroller

• Check if capital letter or number

• Write to port binary sequence

C ++ PROGRAM

             /* Change ASCII to Braille */                switch (int(next))                {                // Lower Case Letters                case 101: case 69:                // e - 010001                  portchar = 0x11;                  write(port, &portchar, 1);                        break;                case 116: case 84:                // t - 011110                  portchar = 0x1e;                  write(port, &portchar, 1);                        break;                case 97: case 65:                 // a – 000001

portchar = 0x01;                  write(port, &portchar, 1);                        break;

DRIVER CIRCUIT

RESULTS

RESULTS

a

RESULTS

b

RESULTS

c

TOTAL COST

Scanner: $50

Microcontroller: $150

OCR software: free

6 Solenoids: $20

Circuit components: $10

Casing materials: + $20

$250

SUMMARY

FUTURE WORK

• Finish mechanical casing

• Improve scanner

• Improve OCR

• Run SANE from C++ program

• Make portable

REFERENCEShttp://dots.physics.orst.edu/gs_index.htmlhttp://jocr.sourceforge.net/http://www.aagi.com/http://www.allelectronics.com/http://www.alva-bv.nl/alvacorp/alva_corp_home.asphttp://www.askoxford.com/asktheexperts/faq/aboutwords/frequencyhttp://www.braillenet.net/accessibilite/livreblanc/english/affbraille.htmlhttp://www.freedomscientific.com/http://www.htwm.de/acmc/mcmodule.htmhttp://www.k10k.net/issues/issue059/golan/dakadaka/braille.htmlhttp://www.kgs-america.com/bc.htmlhttp://www.metec-ag.de/english.htmlhttp://www.nec-tokin.com/english/product/sekisou_e/pa_features.htmlhttp://www.pulsedata.com/http://www.sane-project.org/http://www.vesid.nysed.gov/lsn/stvnews/fall03.htm

ACKNOWLEDGEMENTS

Professor Hedrick

Eugen Schäfer

Roland Pierson

James Howard

Gene Davison

QUESTIONS?