P1258801243HKWAM

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Shivani Jain
Jason Skowronski

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Motivation

• Powergloves are cool!
• Can be used for sign-language recognition, video
  games, wearable computers, ergonomics research,
  etc
• A more ergonomic computer interface for mobile
  users
• Currently, gloves dont measure all the angles or
  are ridiculously expensive
• Immersion Technologys Cyberglove vs. Nintendo
  Powerglove

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Introduction

• The Ultra Power Glove is an input device with a
  low-power wireless transmitter to transmit the
  position of the fingers and hand back to the unit
  using wireless technology.
• A video gamer can interact with the game world
  using his own hands.
• Cost of Virtual Reality gloves as opposed to this
  new technology we developed will allow us to
  measure accurately the joint positions for only a
  few dollars in parts per hand.

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Ultimate Objective
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DESIGN PROBLEMS
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Problem

• Determine finger angle without obstructing the
  user or constraining movement
• Small and low power
• Large batteries are heavy and large circuit
  boards are awkward
• Low cost for consumer market

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Solution

• Glove with sensors mounted on top side of hand
• Circuit board with small surface mount
  components, thin connector wires
• Low power wireless
• AA battery to power it

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Problem Two

• Patents on bend sensors prohibit our using common
  bend sensors in commercial products
• Side-to-side rotation cannot be detected using
  inexpensive sensors

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Solution

• Translate bend into a measurable perimeter
  displacement using a mechanical structure

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Multidimensional Displacement Sensor

• Intensity received by each detector is a function
  of the relative angle and displacement from the
  transmitter
• Requires minimum 1 detector per dimension
• Additional detectors add robustness
• LED is a transmitter and 1 phototransistors are
  detectors

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Direction Vectors (2-axis)
vl pl
v1
p1
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Transcendental Function

• Unfortunately, our derivation lead to a
  transcendental equation which can only be solved
  graphically

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Approximation

• LEDs and phototransistors have narrow-angle
  lenses with Gaussian profiles
• Use this to create a natural weighting function
• Slightly overestimates angle
• Requires precise spacing

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Design

• Array of phototransistors detect displacements
• PIC microcontroller reads A/D converters on I2C
  bus, sends data on UART to wireless transceivers
• Software on PC normalizes the voltages and
  calculates the angles, then draws on screen using
  OpenGL

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Components USED

• Phototransistors Measure the distance to a
  nearby LED, outputs voltage from 0-5V
• A/D Converter Digitizes voltage outputs of
  phototransistors. Each has 8 analog inputs and
  presents an I2C interface to the microcontroller.
• Microcontroller A PICmicro Flash
  microcontroller. It queries A/D converters for
  data and sends it out on a UART interlink.
• Transceiver Converts UART data from
  microcontroller to a wireless signal which is
  received by the PC.
• Power Consists of a battery, a switch, and two
  voltage regulators to supply the necessary
  voltages to the components.

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ORIGINAL DESIGN
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• Implementation

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Implementation Of the Project

• SECTION 1 LEDs and phototransistors
• Tested all LEDs and phototransistors for
  functionality.
• Soldered braided wires on all of them
• Insulated the joint of the wire and the
  LED/phototransistor.
• Glued the completed component to the Glove.
• Connected the wires to a SIP connector.

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LEDs and phototransistors
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• SECTION 2 A/D Convertor and PIC
• SIP connector sends inputs to the A/D convertors.
• The channel inputs of the A/D convertor took in
  the signals coming in from the phototransistors
  and converted it to digital outputs .These were
  sent to the PIC.

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• SECTION 3 PCB DESIGN
• The printed Circuit Board required almost 2 weeks
  of work.
• We used EASY TRAX to make the PCB.
• We ordered surface mount parts to keep our glove
  as compact as possible.
• The top and the bottem layer were used.
• An external toggle switch on the PCB.

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PRINTED CIRCUIT BOARD
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SECTION 4 INTEGRATIONWe integrated the software
and hardware using wireless technology
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• TESTING

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LEDs and phototransistors
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TESTING THE LED and phototransistor together
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Other Tests

• Test Vcc for relatively small voltage ripple
• Test data busses with oscilloscope for proper
  activity and voltage levels
• Verify wireless data output in Hyperterminal,
  both text and binary
• Set debug points in code to verify calculation
  outputs
• Visually inspect finger bend in OpenGL

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SUCCESSES

• Achieved bending of fingers from bottom to top
  and side to side
• Achieved making a PCB thats fits on the glove
  with complete circuitry ,thus making our glove
  completely mobile.
• Professor Carney likes it ! ?
• IT WORKS !!!!!!

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Challenges

• Perceived mangitude of incoming intensity
  dependant upon angle causing ripple in
  metacarpophalangeal joints
• Calibration steps records array of intensities at
  each angle, ran a smoothing function on values,
  inversed and multiplied by angle

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Challenges

• Voltage ripple on PCB was much higher than on
  protoboard despite identical components, removed
  DC-DC converter on PCB
• Resistor bars from parts shop had incorrect
  resistances yielding PCB unusable
• Wireless transciever had a firmware problem
  causing twitching

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FUTURE

• Our ulimate objective is to make a Wearable
  Thin Client.
• Imagine a screen floating in front of your eye,
  when you move your hand the cursor moves.
• Using your hand in place of a keyboard.
• The screen shows your desktop, complete with AIM,
  eBay, anything else you like.
• A mobile wireless computer.

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Acknowledgements

• Prof. Scott Carney
• TA Richard Cantzler (Marty)
• ECE parts shop

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QUESTIONS ?