Tacit (The Tacit Project), the brain child of Steve Hoefer, is a glove like accessory that can help blind and visually impaired people navigate without bumping into obstacles. Still a prototype, Tacit uses ultrasonic sensors that determine the distance between the user and an obstacle. There are primarily three components that Tacit uses:
Ultrasonic sensors that send out ultrasonic pulses. These pulses hit obstacles and deflect back to the sensors.
A Microcontroller that detects the amount of time for the ultrasonic pulses to return, and tells the
Servo Motors to rotate with varying amounts of pressure.
The closer the distance, the more pressure is applied by the servo motors on the wrist. At a time, either the left or right servo motor would rotate, letting the user know where the obstacle is.
The diagram above suggests that Tacit is powered by a 9V battery.
Steve has released this project under the Creative Commons BY-NC-SA license, which means that anyone can learn from this prototype, modify it, and make it better, and share the information (and let him know if anyone plans to sell the modified product). Steve thinks that lasers would perhaps provide better results but at the same time make the product much more expensive. The total cost of raw materials used for Tacit is $65.
To read more technical details and to get the source code, click here.
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