Optical Encoder for a Game Steering Wheel May05-26
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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
Introduction
Research
Design
Implementation
Testing
Closing
Introduction
Definitions
Analog to digital conversion (ADC)
Cycles per revolution (CPR)
Hardware interface driver (HID)
Optical encoder
Printed circuit board (PCB)
Potentiometer
Acknowledgements
Thomas Enterprises
Andy Bice – original designer
Dr. Jacobson and Dr. Davis
Problem Statement
Old design senses 256 positions
USB connectivity
New design must sense 1024 positions
Cost of $150
Solution Approach
Solution Approach
Optical encoders replace potentiometers
New microcontroller handles 16 bit input
and is compatible with old microcontroller
Assembly code interprets steering wheel
motion
Operating Environment
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
Serious video gamers
Race car drivers
Typically age 12–30 with a familiarity with
computers
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®
Assumptions
Modify existing PIC Assembly code
Original design available
Use of second power source
Limitations
Same PCB size
Optical encoder placement
$150 maximum cost
PCB should have all the same
connections, inputs, and outputs
Expected End-Product
More sensitive steering wheel
1024 positions from wheel and pedals
Same PCB dimensions
At least prototype quality
Present Accomplishments
New PCB fabricated and assembled
Assembly code written
USB recognizes device
Currently developing button algorithms
PCB tested for electrical connectivity
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
Research Activities
USB 1.1 vs. 2.0
Quadrature Amplitude Modulation
decoding
Microcontroller selection
Part ordering
PCB fabrication
Design Activities
Design Activities
Design circuit
Layout circuit in Eagle
Code written in MPLAB
Programming Flowchart
Schematic
Circuit Layout
Implementation Activities
Send circuit layout designs to be
fabricated
Solder components to PCB
Compile code
Program microcontroller
Testing and Modification
Activities
Tested PCB for electrical connectivity
Optical encoder response
Product functionality
By team members
By non-team members
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
Successful completion
Exceeded design requirements
Old product can be easily upgraded
Product is extensible
Much less than expected cost
Commercialization
Upgrade existing product
Sell new product
Recommendations for Additional
Work
Future upgrades possible
Optical encoders with higher resolution
More pushbutton inputs
Additional Features
Gauges
LEDs
Force Feedback
Lessons Learned
Technical Knowledge
Optical encoders
Microcontrollers
Circuit board layout
Use previous work as much as possible
Begin implementation and testing earlier
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
Summary
Problem
Upgrade steering wheel controller for Thomas
Enterprises
Solution
Replace potentiometers with optical encoders
Upgrade microcontroller
Result
Functional upgrade to previous design
Questions?