The Audible Warning

1
The Audible Warning

• Sonic Sensor System

2
Introductions

• Patrick Gianelli
• Project Manager and Electrical Engineer
• Paul Stegner
• Mechanical and Electrical Engineer
• Matthew Lauver
• Mechanical Engineer
• Christopher Yorgey
• Programmer and Computer Engineer

3
Background

• Project proposed by Mother
• Her daughter is handicapped
• Uses a wheelchair to gain mobility
• Can sometimes collide with walls and doors

4
Assignment

• Design and build system to attach to a
  wheelchair that will
• Give an audible warning when approaching objects
• Increase the volume as objects come nearer
• Have a manual disable switch
• Be removable to protect from the elements
• Must be mountable on a wheelchair
• Power supply must be rechargeable

5
Design

• Processor
• Basic Stamp
• Programmed in a language based off Visual Basic
• Allows for customization of responses of sensor
  units
• Stats
• Speed- 50 MHz
• 10,000 instructions/ second
• RAM- 64Mbytes

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Parallax Ultrasonic Sensors

• Parallax Ultrasonic Sensors
• Programmed for specific distances
• Two for front and two for sides
• Range 3 cm 3.00m
• Sensitivity Can detect 3 cm diameter broom at
  2.00 m from the sensor
• Voltage- 5V
• Frequency- 40kHz
• Beyond hearing level of humans
• Minimum time between scans
• 10 µS

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Construction

• Learning the Basic language
• First we made an LED flash
• Next we got a buzzer to make noise
• Finally we integrated a sensor to trigger the
  buzzer
• We set different distances equal to different
  output frequencies
• Next we edited the program so that it would apply
  to four sensors
• In trying to make the processor work faster it
  became erratic.
• To solve this problem we wrote In a time delay

8
Circuitry

• Issues include
• Setting the pins on the Basic Stamp board to
  agree with the program
• Wiring the sensors into the board
• We chose to use phone jacks because they are
  easily removable
• Finding an optimal speaker
• Trade off between volume and frequency range
• Using precision soldering on the sensors

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Cleaning Up the Circuitry
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Hardware

• Weather Resistant
• Incased the different elements in project boxes
• Board mounting
• Used stand-offs and mounted the board into its
  project box
• Mounting to Wheelchair
• Velcro makes the project boxes easily removable
  to avoid poor weather

11
Power

• Regular 9V batteries only last approximately 5
  hours
• We decided to tap the power of the wheelchair
• It is recharged daily
• Then the problem became dropping the wheelchairs
  12v to our required 9v
• Created a voltage regulator to solve this problem
• See diagram

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Budget

• Item
  Quantity Price
• Ultrasonic sensors 4 35.00
• Starter kit 1 130.00
• Interface board
• Chip
• Project Boxes 6 3.50
• Switch 1 1.20
  
• Speaker 1 2.00
• Wire 15.00
• Phone Jacks 4 6.00
• ICs/ circuitry components 60.00
• An A in Engineering 4
  Priceless
• TOTAL Approximately 390.00

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Das End!