The SMA Wires Application in the Braille Monitor

Abstract

The main aim of the research was to establish whether SMA wires are suitable to build a Braille tactile display. The particular goals were to design, fabricate and programme a device, which would be cheap, convenient and easy to use, and would work independently from the PC. The prototype was to have one letter at least and be ready to add more letters in the future. In the article the conception of the prototype design is presented. The single pin was designed in the shape of a vertical cylinder of 3 mm in diameter. A significant disadvantage of modern Braille monitors is the length of the piezo crystals that prevents engineers from building large matrices. Thanks to SMA wires the possibility to build a large matrix is unlimited. Having built a Braille letter prototype the research on the selection of an appropriate control method was launched. Eventually, it was decided that all of the control tasks would be covered by one single chip – the PIC18F4455 processor. This unit had all the necessary peripherals, such as USB, timers, as well as enough speed to run the software. The designed device has proved that SMA wires can be used for this kind of application [2]. It has also demonstrated that graphic Braille monitors can be built. In the current stage of research, this design is not ready for mass production, but additional research can lead to the improvement of this device.