Optical Encoder for a Game Steering Wheel May05-26

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Optical Encoder for a Game Steering WheelMay05-26

• 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

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Outline

• Introduction
• Research
• Design
• Implementation
• Testing
• Closing

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Introduction
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Definitions

• Analog to digital conversion (ADC)
• Cycles per revolution (CPR)
• Hardware interface driver (HID)
• Optical encoder
• Printed circuit board (PCB)
• Potentiometer

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Acknowledgements

• Thomas Enterprises
• Andy Bice original designer
• Dr. Jacobson and Dr. Davis

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Problem Statement

• Old design senses 256 positions
• USB connectivity
• New design must sense 1024 positions
• Cost of 150

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Solution Approach
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Solution Approach

• Optical encoders replace potentiometers
• New microcontroller handles 16 bit input and is
  compatible with old microcontroller
• Assembly code interprets steering wheel motion

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Operating Environment

• Temperature of approximately 70F
• No moisture
• Mostly dust-free conditions
• Not intended to be dropped or thrown, but could
  withstand a drop from 2 - 3 feet

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Intended Users

• Serious video gamers
• Race car drivers
• Typically age 1230 with a familiarity with
  computers

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Intended Uses

• 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

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Assumptions

• Modify existing PIC Assembly code
• Original design available
• Use of second power source

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Limitations

• Same PCB size
• Optical encoder placement
• 150 maximum cost
• PCB should have all the same connections, inputs,
  and outputs

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Expected End-Product

• More sensitive steering wheel
• 1024 positions from wheel and pedals
• Same PCB dimensions
• At least prototype quality

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Present Accomplishments

• New PCB fabricated and assembled
• Assembly code written
• USB recognizes device
• Currently developing button algorithms
• PCB tested for electrical connectivity

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Approaches Considered and One Used

• 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

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Research Activities

• USB 1.1 vs. 2.0
• Quadrature Amplitude Modulation decoding
• Microcontroller selection
• Part ordering
• PCB fabrication

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Design Activities
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Design Activities

• Design circuit
• Layout circuit in Eagle
• Code written in MPLAB

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Programming Flowchart
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Schematic
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Circuit Layout
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Implementation Activities

• Send circuit layout designs to be fabricated
• Solder components to PCB
• Compile code
• Program microcontroller

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Testing and Modification Activities

• Tested PCB for electrical connectivity
• Optical encoder response
• Product functionality
• By team members
• By non-team members
• Delayed programmer update

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Resources and Schedules
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Personnel Effort Requirements
Total hours 340
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Other Resource Requirements
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Financial Requirements
Item   Total Price w/o Labor Total Price with Labor
16-bit Microcontroller   13.00 13.00
Optical Encoder   156.00 156.00
Power Supply   5.38 5.38
Circuit Board Fabrication   100.00 100.00
Miscellaneous Parts   19.69 19.69
  Subtotal 294.07 294.07
Miscellaneous Resources Miscellaneous Resources    
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
  Subtotal 96.00 96.00
Labor at 10.50/hour      
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
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Schedules
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Conclusion
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Project Evaluation

• Successful completion
• Exceeded design requirements
• Old product can be easily upgraded
• Product is extensible
• Much less than expected cost

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Commercialization

• Upgrade existing product
• Sell new product

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Recommendations for Additional Work

• Future upgrades possible
• Optical encoders with higher resolution
• More pushbutton inputs
• Additional Features
• Gauges
• LEDs
• Force Feedback

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Lessons Learned

• Technical Knowledge
• Optical encoders
• Microcontrollers
• Circuit board layout
• Use previous work as much as possible
• Begin implementation and testing earlier

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Risk and Risk Management

• Anticipated Risks
• 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
• Changes in Management
• Procured parts through advisors
• Outside resources

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Summary

• Problem
• Upgrade steering wheel controller for Thomas
  Enterprises
• Solution
• Replace potentiometers with optical encoders
• Upgrade microcontroller
• Result
• Functional upgrade to previous design

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Questions?