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 Introduction Research Research Design Design Implementation Implementation Testing Testing Closing Closing

Introduction

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

Acknowledgements Thomas Enterprises Thomas Enterprises Andy Bice – original designer Andy Bice – original designer Dr. Jacobson and Dr. Davis Dr. Jacobson and Dr. Davis

Problem Statement Old design senses 256 positions Old design senses 256 positions USB connectivity USB connectivity New design must sense 1024 positions New design must sense 1024 positions Cost of $150 Cost of $150

Solution Approach

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

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

Intended Users Serious video gamers Serious video gamers Race car drivers Race car drivers Typically age 12–30 with a familiarity with computers 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 In home at a table or desk on video games that are played on a personal computer Used in racing games Used in racing games Not used on game consoles such as Sony Playstation® or Nintendo Gamecube® Not used on game consoles such as Sony Playstation® or Nintendo Gamecube®

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

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

Expected End-Product More sensitive steering wheel More sensitive steering wheel 1024 positions from wheel and pedals 1024 positions from wheel and pedals Same PCB dimensions Same PCB dimensions At least prototype quality At least prototype quality

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

Approaches Considered and One Used Adapt previous design to meet new expectations Adapt previous design to meet new expectations Add quadrature amplitude modulation decoder to previous design Add quadrature amplitude modulation decoder to previous design New microcontroller is pin-for-pin compatible with advanced features New microcontroller is pin-for-pin compatible with advanced features

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

Design Activities

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

Programming Flowchart

Schematic

Circuit Layout

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

Other Resource Requirements

Financial Requirements Item Total Price w/o LaborTotal Price with Labor 16-bit Microcontroller $13.00 Optical Encoder $ Power Supply $5.38 Circuit Board Fabrication $ Miscellaneous Parts $19.69 Subtotal$ Miscellaneous Resources Poster $60.00 Project Plan Binding $12.00 Design Document Binding $12.00 Final Report Binding $12.00 Subtotal$96.00 Labor at $10.50/hour Dahlke, Samuel $0.00$ Fecteau, Peter $0.00$ Pates, Daniel $0.00$ Subido, Lorenzo $0.00$ Subtotal$0.00$2, Total$390.07$3,340.57

Schedules

Conclusion

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

Commercialization Upgrade existing product Upgrade existing product Sell new product Sell new product

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

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

Risk and Risk Management Anticipated Risks Anticipated Risks Loss of work and loss of a team member Loss of work and loss of a team member Risks Encountered Risks Encountered Time required to procure parts Time required to procure parts Departure of previous designer Departure of previous designer Microcontroller not well supported yet Microcontroller not well supported yet Changes in Management Changes in Management Procured parts through advisors Procured parts through advisors Outside resources Outside resources

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

Questions?