Braillebook Refreshable Braille Display October 19, 2015 Department of Electrical & Computer Engineering 1 1

Team Braillebook Richard Lam EE, ‘16 Team Manager Raveena Kothare Steven Golonka EE, ‘16 Faculty Advisor: Professor Dennis Goeckel Department of Electrical & Computer Engineering 2 2

Department of Electrical & Computer Engineering Introduction Braille is a tactile writing system used by visually-impaired individuals Braille literacy is positively correlated with1: Education Employment Income Department of Electrical & Computer Engineering [1] https://www.nbp.org/ic/nbp/braille/needforbraille.html 3 3

Department of Electrical & Computer Engineering Motivation Today, 10% of blind children are taught Braille2 Compare to 50% in the 1950s Braille texts are expensive Costs several times more than ordinary books Electronic refreshable Braille displays cost $2000-$80003 74% of working-age blind people are unemployed1 Depend on disability income benefits [2]http://www.economist.com/news/international/21595475-new-technology-could-save-writing-system-blind-joining-dots [3]http://www.bbc.com/news/technology-27243376 Department of Electrical & Computer Engineering 4 4

Department of Electrical & Computer Engineering Meet Camille Blind Braille-user Learned in grade school Master’s degree in Rehabilitation Counseling Formerly employed by: State of Connecticut Springfield Technical Community College Perkins School for the Blind //Play audio of: “My comprehension is better with braille than with audio and it’s always been that way.” Department of Electrical & Computer Engineering 5 5

Department of Electrical & Computer Engineering Meet Camille “My comprehension is better with braille than with audio and it’s always been that way…” //Play audio of: “My comprehension is better with braille than with audio and it’s always been that way.” Department of Electrical & Computer Engineering 6 6

The Goal A low-cost, quickly refreshing, dynamic Braille display 7 Talk about how it would work- text file is loaded onto device, row of characters is displayed, user presses buttons to go to next/previous line Can be used in workplace or recreationally Department of Electrical & Computer Engineering 7 7

Department of Electrical & Computer Engineering Requirements - User Can load text files to device via USB 2.0 to computer Powered by standard wall outlet No larger than 50x15x12 cm Device controls are easy to locate for a blind person Power ON/OFF Select loaded text file Shift NEXT/PREVIOUS line Displays at least 20 Braille cells in 1 line Possibility of implementing multiple lines Line refreshes in no more than 5 seconds Costs <$400 Mention that a display of 32 characters costs $2,000 and Department of Electrical & Computer Engineering 8 8

Department of Electrical & Computer Engineering Braille Dimensions By American Library of Congress standards4: Dot to dot (a, b) = 2.5 mm Cell to Cell (c) = 6.25 mm Line to Line (d) = 10 mm Dot diameter (e) = 1.25 mm Dot height = 0.5 mm Consider putting up a braille cell diagram with dimensions Department of Electrical & Computer Engineering [4] http://www.tiresias.org/research/reports/braille_cell.htm 9 9

Department of Electrical & Computer Engineering Block Diagram Department of Electrical & Computer Engineering 10 10

Possible Electromechanical Designs Solenoid-Driven Pins Belt-Driven Carriage Octagonal Wheels Ask goeckel if we can use/try the Haverford method Department of Electrical & Computer Engineering 11 11

Design Option - Solenoids and Pins Very few moving parts Less need for precision control Difficult to scale down in size Six solenoids per character Department of Electrical & Computer Engineering 12

Design Option - Belt-Driven Carriage Simple linear motion using a conveyer belt Vertical motion achieved through solenoids or linear actuators Solves scalability issue of the Solenoid and Pin idea Difficult to ensure carriage is in the correct position Department of Electrical & Computer Engineering 13

Design Option - Octagonal Wheels Simple way to change characters Spin from one position to the next Difficult to control individual wheels Close together Large number of them Implementation can be done in multiple ways Different spinning mechanisms Different holding mechanisms Department of Electrical & Computer Engineering 14 14

Octagonal Wheels - Electromagnets Removes the need for precision of motor control Electromagnetic interference becomes a problem Size of electromagnets is a concern EM EM EM EM EM EM EM EM Permanent Magnet Department of Electrical & Computer Engineering 15 15

Octagonal Wheels - Electromagnets Removes the need for precision of motor control Electromagnetic interference becomes a problem Size of electromagnets is a concern EM EM EM EM EM EM EM EM Permanent Magnet Department of Electrical & Computer Engineering 15 16

Octagonal Wheels - Electromagnets Removes the need for precision of motor control Electromagnetic interference becomes a problem Size of electromagnets is a concern EM EM EM EM EM EM EM EM Permanent Magnet Department of Electrical & Computer Engineering 15 17

Octagonal Wheels - Electromagnets Removes the need for precision of motor control Electromagnetic interference becomes a problem Size of electromagnets is a concern EM EM EM EM EM EM EM EM Permanent Magnet Department of Electrical & Computer Engineering 15 18

Octagonal Wheels - Electromagnets Removes the need for precision of motor control Electromagnetic interference becomes a problem Size of electromagnets is a concern EM EM EM EM EM EM EM EM Permanent Magnet Department of Electrical & Computer Engineering 15 19

Octagonal Wheels - Ratchet and Solenoid Only two solenoids per character Held in place with a spring and bar Difficult to implement Solenoid cannot rotate disk without hitting the following side Department of Electrical & Computer Engineering 16 20

Octagonal Wheels - Axle and Key Octagonal disks are supported by a stationary axle Key, capable of linear and rotational motion, adjusts each disk sequentially Department of Electrical & Computer Engineering 17 21

Department of Electrical & Computer Engineering Block Diagram Department of Electrical & Computer Engineering 18

Problem - How to Maintain Disk Position Individual disks must be prevented from moving unintentionally Possible solutions: Spring Hold Method Sliding Bar Method Department of Electrical & Computer Engineering 19 23

Axle and Key - Hold Methods Spring Hold Method Disks are notched on each side Uses a spring and bar to hold octagonal disks in place Rotational force of the Set Character Mechanism provides enough force to lift the bar by rotating the disk Department of Electrical & Computer Engineering 20 24

Axle and Key - Hold Methods Sliding Bar Method Uses an extra key that enters and exits from the opposite end of the device The second key follows the Set Character Mechanism and holds disks in position Department of Electrical & Computer Engineering 21 25

Department of Electrical & Computer Engineering Block Diagram Department of Electrical & Computer Engineering 22

Software Design - User Interface Requirements: Device can be loaded with text files on computer with assistance of visually-abled person Simple, easy to use GUI Implementation: Java applet for Windows Department of Electrical & Computer Engineering 23 27

Software Design - Microcontroller Text-to-Braille Algorithm Input: ASCII text file Output: 2-integer code per ASCII character corresponding to desired disk orientation Disk Rotation Algorithm Input: List of desired end states for disks Output: Pattern of turns to be implemented by linear and rotational motors Motor Control Implements pattern generated by Disk Rotation Algorithm Department of Electrical & Computer Engineering 24 28

Department of Electrical & Computer Engineering Block Diagram Department of Electrical & Computer Engineering 25

Disk Rotation Algorithm – Explained Setting characters from left to right Algorithm calculates number of rotations for each disk Rotation of a given disk affects all disks to the left of it Final positions of disks are achieved once rotation of rightmost disk is complete Example with four sided disk below: Orient all dots at top Department of Electrical & Computer Engineering 26 30

Disk Rotation Algorithm – Explained Setting characters from left to right Algorithm calculates number of rotations for each disk Rotation of a given disk affects all disks to the left of it Final positions of disks are achieved once rotation of rightmost disk is complete Example with four sided disk below: Orient all dots at top Department of Electrical & Computer Engineering 26 31

Disk Rotation Algorithm – Explained Setting characters from left to right Algorithm calculates number of rotations for each disk Rotation of a given disk affects all disks to the left of it Final positions of disks are achieved once rotation of rightmost disk is complete Example with four sided disk below: Orient all dots at top Department of Electrical & Computer Engineering 26 32

Disk Rotation Algorithm – Explained Setting characters from left to right Algorithm calculates number of rotations for each disk Rotation of a given disk affects all disks to the left of it Final positions of disks are achieved once rotation of rightmost disk is complete Example with four sided disk below: Orient all dots at top Department of Electrical & Computer Engineering 26 33

Disk Rotation Algorithm – Explained Setting characters from left to right Algorithm calculates number of rotations for each disk Rotation of a given disk affects all disks to the left of it Final positions of disks are achieved once rotation of rightmost disk is complete Example with four sided disk below: Orient all dots at top Department of Electrical & Computer Engineering 26 34

Disk Rotation Algorithm – Explained Setting characters from left to right Algorithm calculates number of rotations for each disk Rotation of a given disk affects all disks to the left of it Final positions of disks are achieved once rotation of rightmost disk is complete Example with four sided disk below: Orient all dots at top Department of Electrical & Computer Engineering 26 35

Disk Rotation Algorithm – Explained Setting characters from left to right Algorithm calculates number of rotations for each disk Rotation of a given disk affects all disks to the left of it Final positions of disks are achieved once rotation of rightmost disk is complete Example with four sided disk below: Orient all dots at top Department of Electrical & Computer Engineering 26 36

Disk Rotation Algorithm – Explained Setting characters from left to right Algorithm calculates number of rotations for each disk Rotation of a given disk affects all disks to the left of it Final positions of disks are achieved once rotation of rightmost disk is complete Example with four sided disk below: Orient all dots at top Department of Electrical & Computer Engineering 26 37

Disk Rotation Algorithm – Explained Setting characters from right to left Algorithm calculates number of rotations for the current disk Setting current disk affects all disks to the left of it Algorithm predicts the positions Final position of each disk is achieved one at a time Department of Electrical & Computer Engineering 27 38

Disk Rotation Algorithm – Explained Setting characters from right to left Algorithm calculates number of rotations for the current disk Setting current disk affects all disks to the left of it Algorithm predicts the positions Final position of each disk is achieved one at a time Department of Electrical & Computer Engineering 27 39

Disk Rotation Algorithm – Explained Setting characters from right to left Algorithm calculates number of rotations for the current disk Setting current disk affects all disks to the left of it Algorithm predicts the positions Final position of each disk is achieved one at a time Department of Electrical & Computer Engineering 27 40

Disk Rotation Algorithm – Explained Setting characters from right to left Algorithm calculates number of rotations for the current disk Setting current disk affects all disks to the left of it Algorithm predicts the positions Final position of each disk is achieved one at a time Department of Electrical & Computer Engineering 27 41

Disk Rotation Algorithm – Explained Setting characters from right to left Algorithm calculates number of rotations for the current disk Setting current disk affects all disks to the left of it Algorithm predicts the positions Final position of each disk is achieved one at a time Department of Electrical & Computer Engineering 27 42

Disk Rotation Algorithm – Explained Setting characters from right to left Algorithm calculates number of rotations for the current disk Setting current disk affects all disks to the left of it Algorithm predicts the positions Final position of each disk is achieved one at a time Department of Electrical & Computer Engineering 27 43

Disk Rotation Algorithm – Explained Setting characters from right to left Algorithm calculates number of rotations for the current disk Setting current disk affects all disks to the left of it Algorithm predicts the positions Final position of each disk is achieved one at a time Department of Electrical & Computer Engineering 27 44

Disk Rotation Algorithm – Explained Setting characters from right to left Algorithm calculates number of rotations for the current disk Setting current disk affects all disks to the left of it Algorithm predicts the positions Final position of each disk is achieved one at a time Department of Electrical & Computer Engineering 27 45

Disk Rotation Algorithm – Explained Setting characters from right to left Algorithm calculates number of rotations for the current disk Setting current disk affects all disks to the left of it Algorithm predicts the positions Final position of each disk is achieved one at a time Department of Electrical & Computer Engineering 27 46

Design Considerations Motor control Linear and rotational accuracy Timing of sequential operations Maintaining disk position Refresh rate Scaling down design to size Department of Electrical & Computer Engineering 28 47

Department of Electrical & Computer Engineering MDR Deliverables Produce open-box prototype of Axle and Key design Not scaled to size specifications Set 1 Braille cell Individually control 2 octagonal disks Control motors with microcontroller Device is not responsive in real-time Department of Electrical & Computer Engineering 29 48

Department of Electrical & Computer Engineering Concluding Remarks Steve: Do you think not being able to read braille is detrimental to working in industry? “Now, it’s scary because braille is being deemphasized and because people think audio is the same and braille takes up too much room and this and that, but we’re kind of scared that braille is going to be obsolete someday.… because you don’t get the paragraphs. You don’t get the spelling. You don’t get the punctuation when you’re hearing audio. And other people are interpreting it for you. Where as when you are looking at the braille, you know exactly how it’s laid out.” Department of Electrical & Computer Engineering 30 49

Department of Electrical & Computer Engineering Concluding Remarks Steve: Do you think not being able to read braille is detrimental to working in industry? “Now, it’s scary because braille is being deemphasized and because people think audio is the same and braille takes up too much room and this and that, but we’re kind of scared that braille is going to be obsolete someday.… because you don’t get the paragraphs. You don’t get the spelling. You don’t get the punctuation when you’re hearing audio. And other people are interpreting it for you. Where as when you are looking at the braille, you know exactly how it’s laid out.” Department of Electrical & Computer Engineering 30 50

Questions & Discussion Department of Electrical & Computer Engineering 31 51

Department of Electrical & Computer Engineering 32 52