Haptic Feedback device for the Visually Impaired [Project HALO] using arduino

I recently watched an episode of Stan Lee’s Superhumans which featured a blind
man who used a series of clicks, like a bat, to echo locate his surroundings. I
got to thinking about other blind people and their ability to navigate freely –
without the use of a guide dog or cane. I came up with the idea to use a series
of rangefinders that would take input from sensors and output feedback to pulse
vibration motors placed on a person’s head. As a person gets closer to an object
the intensity and frequency of the vibration would increase – it’s directly
proportional to the distance of an object. If a region was lacking feedback,
then it would be safe to proceed in that direction.

I call my submission the H.A.L.O. – the Haptic Assisted Locating of Obstacles. I
believe this can serve very useful for the visually impaired to have the freedom
to possibily move about hands-free without the assistance of a cane or seeing
eye dog. Technology has undoubtedly made our daily lives better. By using a few
inexpensive components and sensors, I’ve made a device that will allow the blind
to navigate their surroundings and avoid collisions.

Step 1: Overview and Parts List

Major Build Portions of the Project:
– Building the Halo
– Building the Motor Modules
– Building the Haptic Headband
– Wiring the Controller
– Creating the Software

The following is the parts list that will be relevant in the subsequent steps of this Instructable.  

Halo:
– Rigid frame (I used a round embroidery frame)
– Female headers (for the sensors)
– Ultrasonic Rangefinders (Parallax Ping Rangefinders)
– Wire (Wires with male and female leads are convenient)
– Glue
– Twist ties to tidy up wiring
– Soldering station
– Male headers (for creating a bridge to feed 5v and ground
– RJ-45-Term Screw Terminal (2)
– RJ-45 Cable
– Marker

Motor Modules:
– Vibration Motors (5) – Motot, VIB,3V/60mA, 7500RPM
– Grid-Style PC Board
– Male header pins
– Motor “shroud” (to prevent things getting sucked into the motor)

Haptic Headband:
– Headband
– Sewing Kit
– 5 Motor Modules
– Wire (Wires with male and female leads are convenient)
– Safety Pins
– Female headers
– Soldering station
– RJ-45-Term Screw Terminal (2)
– RJ-45 Cable
– Marker

Wiring the Microcontroller:
– Arduino Mega 2560
– Wire (Wires with male and female leads are convenient)
– 5 LEDs
– Darlington IC – ULN 2803A
– 2 port screw terminal
– 9v battery
– 5v regulator

Building the Software:
– USB cable
– PC (for editing code and downloading to Arduino)
– Arduino
– Arduino development environment (www.arduino.cc)
– Source Code, modified Ping.h library

Step 2: Building the Halo

There were a couple of key considerations for the Halo (sensor) portion
of the apparatus. It needed to be rigid in order to reliably range find
the right regions of the space relative to the user facing. I determined
that 5 sensors would be a good number between being overloaded with
information, and lacking sufficient detail and there being gaps in the
field of “vision”.

Full Left (-90 degrees)
Left Center (-45 degrees)
Center (0 degrees)
Right Center (45 degrees)
Full Right (90 degrees)

1- Mark your frame at appropriate locations with a marker.
2- Cut female headers to 3 pins size (these are the receptacles for the ultrasonic sensors)
3- Glue headers to the frame at appropriate positions
4- Solder all the ground wires together (these are the left-most pin looking in to the frame)
5- Solder all of the 5V wires together (these are the center pins)
6- Run individual wire to each signal pin (right most pin)
7- Twist tie loose wiring to frame

8- Terminate all wires into a RJ-45-TERM. This will be sent over an RJ-45 cable to the micro controller for processing.

Step 3: Building the Motor Modules

1- Cut your PC Board into small strips (enough for the 2 male pins to be soldered on). You will need 5 of these. I did this with my bandsaw.
2- Cut the male headers into 2 pins. You will need 5 of these pairs
3- Solder the male header pairs onto the PC board
4- Solder the motor leads to the PC board (direction is not critical)
5- Cover the motor in the “shroud”
6- Glue the PC board to the shroud, with the 2 male pins facing up

For more detail: Haptic Feedback device for the Visually Impaired [Project HALO]