Software And Hardware Design And Development Of Multifunctional Braille Display Device

With the continuous increase in the number of visually impaired people,the demand for blind reading materials in the whole society is Growing with each passing day.However,the development of Braille reading materials can't keep up with the demand,so users' demand for Braille displays is increasing.The main function of the braille display is to convert text information into braille dot matrix.Worldwide,although there are already some Braille displays available,most of them are single-function and expensive,can only display one line of Braille.There is still much room for improvement in user experience.The purpose of this paper is to design a multi-functional braille display hardware system and verify the software technology route.The equipment is based on Hisilicon Hi3559AV100 platform,which can process PDF files copied from a PC.It can parse PDF files by calling a third-party Mu PDF library to achieve real-time preview,text extraction and dot information display.What's more,we can also collect image information through the Sony IMX586 camera,perform image processing and text extraction,and finally convert it into the display of dot information.The main work of this paper is as follows:(1)Frame design of multifunctional braille display.We figured the needs of users through research,determine the software and hardware framework of the system,specify corresponding plans for system software and hardware development,and complete the establishment of software,hardware design and development environment.(2)Design of system hardware circuit.The hardware composition of the entire system is divided into three parts: main board with embedded main chip,mother board with peripheral interfaces and dot module board with contact module.Different PCBs are connected through board-to-board connectors.We need do some simulation and optimization before PCB production to make PCB more reliable.(3)Optimization of multi-contact module driving method.The dot module board is controlled by a low-power microcontroller and communicates with the main chip through a UART interface.We reduce the number of GPIOs By switching the working mode of the dual H-bridge motor driver chip,and the lifting of the dots can be accurately controlled.(4)Development of braille display simulator based on Qt.This simulator is used to complete the PDF file analysis,text and text extraction,real-time preview,and Braille dot matrix information conversion and other verification functions,which can facilitate later software debugging.