SAM REDD

VISION

My goal in building my VISION device was to create an alternative way for the blind, particularly the recently blind, to map their environments. Instead of sight, I used sound. The device consists of a knit hat with an ultrasonic rangefinder on its front, an Arduinbo Lilypad (made for wearable technology), and an earbud that allows the user to hear how far away objects are from them.

For this project, I needed to produce a tone that was extremely soft and non-abrasive, as it would be passed directly into the user's ear via the earbud. The delicate wiring also needed to be safe from being broken apart by normal wear, and the Lilypad version of the Arduino turned out to be difficult to program, lacking the standard USB serial connection found on many microcontrollers.

To smooth the tone, I built a Low Pass Resistor-Capacitor Filter, which only allows low frequencies to be passed to the earbud. This additional circuit, the Arduino, earbud, and all of the wiring were sewn into the fabric of the hat between its outer layer and the inner layer that makes direct contact with the wearer's head. To program the Lilypad, I uploaded the program I had written to an Arduino Uno and passed it serially from there to the Arduino Lilypad.

The device I ended up with produces a soft, even pleasant tone that is inaudible unless the earbud is securly in the user's ear. The tone's pitch increases as objects become closer to the sensor on the front of the hat.