A wireless ranging system for the blind long-cane utilizing a smart-phone

A cost effective and easy-to-use smart-phone based ultrasonic wireless ranging, and collision warning system that is appropriate to complement the long-cane of the visually impaired persons is presented in this paper. This system is intended to increase the safety and the reliability of the mobility aid of the blind while reducing cost by utilizing popular wireless technologies as Bluetooth and a smart-phone along with text-to-speech (TTS) features of mobile devices. The system hardware is composed of an ultrasonic sensor that interfaces to a microcontroller and a Bluetooth transceiver. While the application software runs on the user´s smart-phone or PDA. Laboratory experiments demonstrate that the developed system can effectively detect the presence of obstacles with accuracy in the centimeter range.