Portable Braille e-Book Reader Making RBDs More Accessible Team 10 Mingjie Wang & Rajarshi Roy

Introduction Objectives Design Implementation Future Work Q&A Challenges Tests

Expensive Piezoelectronics Poor Portability

Small Form Factor Removable Storage Interface with Mobile Devices Touch Interface Standalone & Rechargeable Cheap Acceptable Refresh Rate

Power Supply Controller Braille Interface Removable Memory Wireless Transceiver Sensor Power Data

0.019”{

0.057” 0.092” 0.245” 0.674” 0.667”

Sense Board

SD card slot for e-book storage (SPI protocol) Bluetooth Modem interface for SMS receiving (Serial interface) Capacitive Sensor board interface to receive user control gestures (I2C interface) Control Board interface to display characters on Braille cells (Software Serial interface)

Capacitive Touch Sensor Uses the MPR121 IC 12 channels of capacitive touch inputs 10 channels used for vertical scroll resolution 2 channels used for left or right slider determination

Bluetooth Modem Pairs with Bluetooth Devices 2.4Ghz ISM band, Class 2 Bluetooth Device Serial output: 9600 baud rate

Verification: SD card read Firmware verification SD card with text file containing abcd…xyz is inserted into sense board The text data is read into an array and the time in milliseconds is recorded during each array entry using function millis() Finally, the text and time data is presented to serial monitor of PC via FT232RL USB-Serial IC Results: 26/26 characters read correctly (233-36)/25 = 7.88ms per character read

Verification: Bluetooth Modem Firmware verification 160 character SMS containing repeated text “thequickbrownfoxjumpedoverthelazydog” is sent from Samsung Nexus S phone to sense board at distances: greater than 0m, 1m, 2m, 3m, 4m, 5m, 6m, 7m, 8m, 9m, 10m, … Finally, the text data is presented to serial monitor of PC via FT232RL USB-Serial IC Results: 160/160 characters successfully received at distances <10m Exceeded initial requirement of 1m range

Verification: Capacitive Sensor Firmware verification SD card with text abcde…….xyz is inserted into sense board. Capacitive sensor is connected to sense board Finally, the data is presented to serial monitor of PC via FT232RL USB- Serial IC Data consists of touch detection per pad, character in text based on scrolling gesture, output “hold detected” if hold gesture is detected User first touched all pads, then user scrolls up from a to z, then user scrolls down from z to a, then user pressed both sliders for greater than 3 seconds Results: #sense pads detected: 12/12 #scroll up works: 26/26 #scroll down works: 26/26 #holds that work: 10/10

Verification: Braille Interface Video / picture set showing aa, bb, cc, dd, ee, ff, gg, hh, ii, jj, kk, ll, mm, ….

$81.33 Servos 12 X 3.99 Wireless Bluetooth Module mAh 7.4V 15C LiPo 4.67 MIC YM 2 X 1.63 MIC ATMEGA328P-AU 2 X 3.05 Tactile Switch 2 X 0.61 MicroSD socket 1.97 Green LED 2 X MHz ceramic resonator 2 X 0.66 MPR121QR Passives 0.15

Acknowledgements Electronic Service Shop – Mark, Scott, Dan, Wally Champaign-Urbana Community Fab Lab TAs – Jane, Alex Fellow course mates

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