Optical Encoder for a Game Steering Wheel May

Optical Encoder for a Game Steering Wheel May 05 -26 Client: Thomas Enterprises Advisors: Dr. James Davis Dr. Douglas Jacobson Team Members: Sam Dahlke, Cpr. E Peter Fecteau, Cpr. E Daniel Pates, EE Lorenzo Subido, EE April 19, 2005

Outline Introduction n Research n Design n Implementation n Testing n Closing n

Introduction

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

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

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

Solution Approach

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

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

Intended Users Serious video gamers n Race car drivers n Typically age 12– 30 with a familiarity with computers n

Intended Uses In home at a table or desk on video games that are played on a personal computer n Used in racing games n Not used on game consoles such as Sony Playstation® or Nintendo Gamecube® n

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

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

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

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

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

Research Activities USB 1. 1 vs. 2. 0 n Quadrature Amplitude Modulation decoding n Microcontroller selection n Part ordering n PCB fabrication n

Design Activities

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

Programming Flowchart

Schematic

Circuit Layout

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

Testing and Modification Activities n n n Tested PCB for electrical connectivity Optical encoder response Product functionality By team members n By non-team members n n Delayed programmer update

Resources and Schedules

Personnel Effort Requirements Total hours: 340

Other Resource Requirements

Financial Requirements Item Total Price w/o Labor 16 -bit Microcontroller Total Price with Labor $13. 00 $156. 00 $5. 38 $100. 00 $19. 69 $294. 07 Poster $60. 00 Project Plan Binding $12. 00 Design Document Binding $12. 00 Final Report Binding $12. 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 n Successful completion Exceeded design requirements n Old product can be easily upgraded n Product is extensible n Much less than expected cost n

Commercialization n Upgrade existing product n Sell new product

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

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

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

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

Questions?