We are developing a system to help blind people sense their surroundings beyond the range of a standard walking cane. Using low-cost, open source, wearable electronics we hope to produce a set of technologies and methodologies that can be easily replicated and customized by others.
The first prototype uses under $100 in parts, using an Arduino board, a vibration motor and an ultrasonic range finder to translate a single point of depth data into varying intensities of tactile output. A similar system could be mass produced for under $40.