Light Leader LED Guitar Trainer

1. Light LeaderLED Guitar Trainer Design II Final Presentation April 19, 2007

2. Team Members Michael Breazeale Responsibilities: Software, Firmware, Circuit Design, Research, Documentation, Testing & Debugging Harry Lam Responsibilities: Software, Research, Documentation, Testing & Debugging Truong Nguyen Responsibilities: Circuit Design, Research, Documentation, Testing & Debugging

3. Presentation Outline • Problem Description • Our Solution • Technical Constraints/Test Results • Practical Constraints • Teaming and Division of Labor • Design Refinements/Packaging • Field Test • Conclusion • Questions

4. Typing Without Letters • Remember when you first began typing. • Imagine if there were no letters on the keyboard. • Diagram

5. How Can You Learn Guitar? • Teach yourself [1] • Books, DVDs, and Software • Instructor [2] • FretLight FG-421 [3]

6. FretLight Has Advantages… Advantages • Teaches interactively • Guides users through lessons and songs • USB powered But… • How do people begin playing guitar? • Borrow or buy a cheap beginner guitar • Learn through books, or taking lessons from a friend or guitar instructor Disadvantages: • Limited guitar styles • Expensive to repair • Costs $500-$900 It’s EXPENSIVE!

7. The Solution - Light Leader LED Guitar Trainer Light Leaders advantages • Teaches interactively • Guides users through lessons and songs • USB powered • Can be used with any standard guitar • Inexpensive to repair • Costs $99

8. Light Leader-Basic Overview • Thin LED strap • Adjustable for various guitars • USB Data/Power • Low cost materials • Software

9. Technical Constraint/Test Result:Weight and Thickness • Less than 1 lb • Test Result: 7oz. • Less than 1mm thick • Test Result: 0.7mm

10. Technical Constraint/Test Result:Current Draw • Test Results: Current Varied • Max Current: 90mA • Average Current: 44-50mA • Correlation between USB data stream and current • Light Leader should draw less than 50mA • USB recommended current is 100mA • Why not use the recommended current? • LEDs fluctuate • microprocessors fluctuate • safety of overall design

11. Technical Constraint/Test Result:Visibility • Viewable from a 1 m distance • LEDs provide 3 mlx of illuminance • Test Results: 13mA through LEDs • LED illuminance at 13mA is 4.6 mlx

12. Technical Constraint/Test Result:Software Functionality • Chords must match LEDs • Metronome must be consistent • Audio samples must be accurate • Confirmed in field tests

13. Technical Constraint/Test Result:Responsiveness • Under 1 ms delay • Appear “instantaneous” • Tested in software timing • Transmit minimal data • Code optimization

14. Practical Constraint:Economic-Bill of Materials Total Cost: $49.39 *Costs based on the purchase of 100 units

15. Practical Constraint:Manufacturability • LED Strap must be thin and durable, and must accurately fit the neck of the guitar. • Labor cost should be minimized. • Connection between the USB communication system and the LED strap must be secure.

16. Teaming and Division of Labor • Three subsystems • GUI, USB, LED • Maximize individual strengths • Designs co-dependent on each other • Product testing joins all parts together • Collaborative debugging and problem-solving

17. Design Refinement/Packaging:Software • Change audio output from beeps to recorded guitar. • Makes sound more natural and accurate. • Package a user-friendly installation program to setup all files on other PCs.

18. Design Refinement/Packaging:LED Strap • Use one FPCB, instead of 13 individual FPCBs • Reduces labor costs. • Space LEDs out to reflect the widening of the strings along the neck. • Utilize 2-layer FPCB to centralize the connection between the LED strap and the USB Communication System

19. Design Refinement/Packaging:USB Communication System • Used SMT microprocessor-smaller board

20. Video of Light Leader

21. Summary • Light Leader is– • interactive • versatile • affordable Questions?

22. References • [1] ezFolk Media Store. (2006, Nov. 28). "Learning Guitar for Dummies," ezFolk Media Store Website. [Online], Available: http://www.ezfolk.com/cgi-bin/ae.pl?asinsearch=B00005OCKA • [2] Ralph Perreta. (2007, Feb. 22). “Guitar Instructor," Guitar Lessons: Brooklyn, New York (Bay Ridge) Teacher. [Online], Available:http://www.bayridgeguitarinstruction.com/ • [3] Fretlight Interactive Learning System. (2006, Nov. 28). “The Fret Light Guitar," Fretlight Website. [Online], Available:http://www.fretlight.com

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24. Prototype Design: Software • Text-based tablature • Scrolls two spaces • Data streaming over USB • Use of pipes • Simple user options • Audio and timer settings

25. Prototype Testing:Software • Verify tablature and LED accuracy • Visual comparison • Verify USB data • Oscilloscope and sniffers • Verify audio correlation • Hands-on testing

26. Prototype Design:LED Strap • Attachment of the Velcro to FPCB • Soldering LEDs and wiring connections • Assemble connection pins for strap to USB communication system • LEDs protective covering

27. Packaging Plan • USB communication system housing • Software and drivers will be included on a CD • Package dimension 5” x 14” x 3”

28. Prototype Testing:LED Strap • Verified all 78 LEDs function • Weight restriction verified using a digital scale • Tested the fret and string LED selection • Verified visibility at 1m • Tested strap thickness with a caliper

29. Prototype Design:USB Communication System • Schematic • Transistor Biasing • Firmware Firmware USB STRING SELECTORS FRET SELECTOR

30. Prototype Testing:USB Communication System • Current Draw • 58 mA with 3 LEDs lit simultaneously • 90 mA with 6 LEDs lit simultaneously • Does not meet constraint, but is acceptable