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

2. 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

3. 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] 3 3

4. 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]
[3]
Department of Electrical & Computer Engineering 4 4

5. 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

6. 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

7. 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

8. 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

9. 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] 9 9

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

11. 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

12. 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

13. 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

14. 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

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 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 16

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 17

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 18

19. 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

20. 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

21. 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

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

23. 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

24. 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

25. 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

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

27. 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

28. 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

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

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 30

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 31

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 32

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 33

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 34

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 35

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 36

37. 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

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 38

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 39

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 40

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 41

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 42

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 43

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 44

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 45

46. 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

47. 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

48. 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

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 49

50. 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

51. Questions & Discussion
Department of Electrical & Computer Engineering 31 51

52. Department of Electrical & Computer Engineering32 52