Hand-Mounted Sonar For the Blind 98
GeekTech.in writes "The Tacit, a wrist-mounted sonar device with haptic feedback, is like strapping a bat to your wrist to help you see. It makes use of two sonar ping sensors to measure the distance to the nearest obstacle. The relative distance to an object is then fed back to the user using two servos which apply pressure to the back of the wrist."
Re:Hot point which summary doesn't mention.. (Score:5, Insightful)
I did something similar for my blind dog, which it used for a year before it died earlier this year. I a circuit like this one as starting point: http://www.kerrywong.com/2011/01/22/a-sensitive-diy-ultrasonic-range-sensor [kerrywong.com], and a cheap vibration motor like this one: https://www.dealextreme.com/p/repair-parts-vibration-motor-for-iphone-4-73348 [dealextreme.com], but you can use a parallax PING module or something similar.
Basically, a controller (I used an atmega chip with an arduino bootloader) that sends pings and moves the motors stronger as the obstacle is closer. Mounted it on the head of the dog, and had the two vibration motors on two sides of the chest. The dog had it figured out in less than a day.
The only "hard" part is that if you go DIY all the way, you'll need an oscilloscope to build the ultrasonic sensor thing, otherwise it is rather simple.