Transcript Optical Encoder for a Game Steering Wheel May05-26

Optical Encoder for a
Game Steering Wheel
May05-26
Client: Thomas Enterprises
Advisors:
Dr. James Davis
Dr. Douglas Jacobson
Team Members:
Sam Dahlke, CprE
Peter Fecteau, CprE
Daniel Pates, EE
Lorenzo Subido, EE
April 19, 2005
Outline
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Introduction
Research
Design
Implementation
Testing
Closing
Introduction
Definitions
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Analog to digital conversion (ADC)
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Cycles per revolution (CPR)
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Hardware interface driver (HID)
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Optical encoder
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Printed circuit board (PCB)
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Potentiometer
Acknowledgements
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Thomas Enterprises
Andy Bice – original designer
Dr. Jacobson and Dr. Davis
Problem Statement
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Old design senses 256 positions
USB connectivity
New design must sense 1024 positions
Cost of $150
Solution Approach
Solution Approach
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Optical encoders replace potentiometers
New microcontroller handles 16 bit input
and is compatible with old microcontroller
Assembly code interprets steering wheel
motion
Operating Environment
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Temperature of approximately 70°F
No moisture
Mostly dust-free conditions
Not intended to be dropped or thrown, but
could withstand a drop from 2 - 3 feet
Intended Users
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Serious video gamers
Race car drivers
Typically age 12–30 with a familiarity with
computers
Intended Uses
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In home at a table or desk on video games
that are played on a personal computer
Used in racing games
Not used on game consoles such as Sony
Playstation® or Nintendo Gamecube®
Assumptions
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Modify existing PIC Assembly code
Original design available
Use of second power source
Limitations
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Same PCB size
Optical encoder placement
$150 maximum cost
PCB should have all the same
connections, inputs, and outputs
Expected End-Product
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More sensitive steering wheel
1024 positions from wheel and pedals
Same PCB dimensions
At least prototype quality
Present Accomplishments
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New PCB fabricated and assembled
Assembly code written
USB recognizes device
 Currently developing button algorithms
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PCB tested for electrical connectivity
Approaches Considered and One
Used
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Adapt previous design to meet new
expectations
Add quadrature amplitude modulation
decoder to previous design
New microcontroller is pin-for-pin
compatible with advanced features
Research Activities
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USB 1.1 vs. 2.0
Quadrature Amplitude Modulation
decoding
Microcontroller selection
Part ordering
PCB fabrication
Design Activities
Design Activities
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Design circuit
Layout circuit in Eagle
Code written in MPLAB
Programming Flowchart
Schematic
Circuit Layout
Implementation Activities
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Send circuit layout designs to be
fabricated
Solder components to PCB
Compile code
Program microcontroller
Testing and Modification
Activities
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Tested PCB for electrical connectivity
Optical encoder response
Product functionality
By team members
 By non-team members
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Delayed programmer update
Resources and
Schedules
Personnel Effort Requirements
Total hours: 340
Subido,
Lorenzo, 24%
Dahlke,
Sam uel, 29%
Pates, Daniel,
24%
Fecteau, Peter,
23%
Other Resource Requirements
Total cost: $390
3%
3%
3%
3%
15%
16-bit Microcontroller
Optical Encoder
Power Supply
Circuit Board Fabrication
Miscellaneous Parts
Poster
Project Plan Binding
Design Document Binding
Final Report Binding
41%
5%
26%
1%
Financial Requirements
Item
Total Price w/o Labor
16-bit Microcontroller
Total Price with Labor
$13.00
$13.00
$156.00
$156.00
$5.38
$5.38
$100.00
$100.00
$19.69
$19.69
$294.07
$294.07
Poster
$60.00
$60.00
Project Plan Binding
$12.00
$12.00
Design Document Binding
$12.00
$12.00
Final Report Binding
$12.00
$12.00
$96.00
$96.00
Dahlke, Samuel
$0.00
$840.00
Fecteau, Peter
$0.00
$693.00
Pates, Daniel
$0.00
$714.00
Subido, Lorenzo
$0.00
$703.50
Subtotal
$0.00
$2,950.50
Total
$390.07
$3,340.57
Optical Encoder
Power Supply
Circuit Board Fabrication
Miscellaneous Parts
Subtotal
Miscellaneous Resources
Subtotal
Labor at $10.50/hour
Schedules
Conclusion
Project Evaluation
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Successful completion
Exceeded design requirements
 Old product can be easily upgraded
 Product is extensible
 Much less than expected cost
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Commercialization
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Upgrade existing product
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Sell new product
Recommendations for Additional
Work
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Future upgrades possible
Optical encoders with higher resolution
 More pushbutton inputs
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Additional Features
Gauges
 LEDs
 Force Feedback
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Lessons Learned
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Technical Knowledge
Optical encoders
 Microcontrollers
 Circuit board layout
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Use previous work as much as possible
Begin implementation and testing earlier
Risk and Risk Management
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Anticipated Risks
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Loss of work and loss of a team member
Risks Encountered
Time required to procure parts
 Departure of previous designer
 Microcontroller not well supported yet
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Changes in Management
Procured parts through advisors
 Outside resources
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Summary
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Problem
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Upgrade steering wheel controller for Thomas
Enterprises
Solution
Replace potentiometers with optical encoders
 Upgrade microcontroller
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Result
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Functional upgrade to previous design
Questions?