The TechBridgeWorld research group at CMU aims to help visually impaired people have a greater involvement in the world. Our Braille Writing Tutor (BWT) and Stand-Alone Braille Writing Tutor (SBWT) devices serve an unmet need for guided braille writing practice in the developing world.

In response to the observed need for enhancing literacy for the blind in underserved communities, the TechBridgeWorld research group at Carnegie Mellon University developed the BWT and later, the SBWT.

TechBridgeWorld’s Braille Writing Tutor (BWT) is an intelligent tutoring device, which helps users learn and practice writing braille using the slate and stylus method. As the user writes on the electronic slate with a stylus, the BWT provides immediate audio feedback by repeating the written letters, numbers or words. It also guides writing and corrects mistakes. The immediate audio feedback serves as a diagnostic tool for instructors, giving them a real-time understanding of what concepts the user did and did not grasp.

The tactile interface consists of an electronic slate, which is connected to a computer through a USB cable. The slate area consists of two rows of sixteen braille cells. An alternate input area consists of six buttons resembling an enlarged braille cell. This was intended for younger braille learners, as well as learners still developing dexterity, to understand the concept of the braille cell, dot numbering, and letter patterns. The USB cable allows the BWT to access power from the computer, and the software is installed on the computer. A standard braille stylus is used and connects a circuit on the BWT when its metal tip is inserted into a braille cell. The electronic slate and wireless stylus produces signals based on the student’s writing actions. These signals are captured and interpreted by the computer, which then provides audio feedback to the user.

The BWT has many educational modes for users to learn how to write, practice writing, and be quizzed on letters, words, and numbers. The software can easily accommodate most braille languages (those with alphabets that have two to the power of six characters or less). Several educational games have been developed for the BWT, which are intended as a further motivation factor for learning to write braille. The software was also designed to use pre-recorded sound files for all feedback and instruction. This feature makes it simple to add customized sounds for each location allowing the use of locally recorded trusted voices with appropriate languages and accents, making the instructions easier to understand for the local students.


The Stand-Alone Braille Writing Tutor (SABT) is an essential upgrade to prior versions of the BT, addressing the same challenges as the BWT as well as those of power failures and lack of reliable computer access in developing communities. The SABT conserves all of the BWT’s features and has several unique features including onboard power (through four AA batteries), an SD card that stores the audio files and configuration files that determine which software modules are to be used in a session, and onboard computing. Standard headphones or speakers can be plugged in.

With tools designed specifically for the millions of visually impaired people living in the developing world, there is a greater chance at achieving braille literacy, access to information, and further inclusion in today’s society.