Hardware Single-Switch Keyboard and Mouse Replacement for Computer Control

A practical, low-cost device is constructed to emulate a computer keyboard and mouse through a single-switch input. Most of the current single-switch computer interface designs focus on simplified hardware implementations with a major portion handled on the destination computer in software. Our device called the PowerKeyboard provides an operating system independent, hardware, single-switch interface for persons of limited mobility or a form of paralysis. A combination of scanning and scrolling techniques provide the available keystroke and mouse control commands on an Liquid Crystal Display (LCD). The triggering of a switch transmits the selected action or executes a stored configuration command of the PowerKeyboard, such as scrolling rate. In this paper, we present the design of the Power Keyboard and compare it to existing designs.