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moBi braille: A text input system for the visually impaired

Special thanks to Praveen Yalal

The idea

moBi braille is mobile text input system for the visually impaired. It is a tool that can be used for getting accustomed to a new keyboard layout  and to provide the user with feedback of the text he is entering through the braille format.

The system attempts  to solve the inadequacies of the current systems of text entry such as braille type writers, which are cumbersome to type on because of the need to have 6 keystrokes to input one character. Other alternatives such as voice input do not provide a reliable feedback  to the user and puts constraints on the kinds of environment the user can use the device in.

Text entry  is an integral part of content generation, self expression and communication and a important means to interact with the digital world. The “qwerty” keyboard is the standard device we use for text entry. It is a fairly efficient way of entering text.Using such a device poses many challenges for the blind. Such as the task of locating the keys and feedback about the characters typed.This system can be incorporated into existing mobile devices or be an integral part of dedicated devices for the blind.

The prototype

The prototype consists of  a  refreshable braille cell which has been positioned such that the index finger covers it under  the normal typing grip.

The image below shows a close up view of the braille cell

 

As the user moves his finger across the keypad the corresponding braille notation of the character is displayed by the braille cell. this would allow the user to familiarize himself with the position of the keys and the layout of the keyboard. This braille cell is also used to display the entered character , this would serve as a feedback to the user to verify his input.

The hardware

The hardware for the prototype consists of a normal keypad which has been wired to detect touches through capacitive measurements.  This keypad is interfaced with an Arduino that controls the six solenoids to actuate the dots in the  braille cell. The solenoids are driven through using a ULN2003 Darlington array.

Future work

I would like to pursue work towards a full commercial prototype which can connect to various devices using Bluetooth. This would allow for the field testing of this system to understand its flaws and  to  take corrective measures. Piezoelectric actuators would  be used instead of solenoids to reduce power consumption and increase reliability.

 

 

References

Tactile Graphics Revised: The Novel BrailleDis 9000 Pin-Matrix Device with Multitouch Input-Thorsten Völkel, Gerhard Weber and Ulrich Baumann.