Reconfigurable PDA for the Visually Impaired Using FPGAs

Abstract

Curtin University Brailler (CUB) is a Personal Digital Assistant (PDA) for visually impaired people. Its objective is to make information in different formats accessible to people with limited visual ability. This paper presents the design and implementation of two modules: a print-to-Braille translation system and a Braille keyboard controller. The translator implements Blenkhorn's algorithm in hardware, liberating the microprocessor to perform other functions. The Braille keyboard controller along with a low cost keyboard provides users with a note-taking function. These modules are used as intellectual property (IP) cores coupled to a 32-bit MicroBlaze processor in an embedded system-on-a-chip (SoC). In its current implementation, the microprocessor uses a hierarchical interrupt scheme to coordinate IP cores. A prototype of the complete embedded system is under development using Xilinx's FPGAs. The system is a potential platform for the development of embedded systems to assist the visually impaired.