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

• Disadvantages
• Limited guitar styles
• Expensive to repair
• Costs 500-900

Its EXPENSIVE!

• 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

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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

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Light Leader-Basic Overview

• Thin LED strap

• Adjustable for various guitars

• USB Data/Power

• Low cost materials

• Software

9
Technical Constraint/Test ResultWeight and
Thickness

• Less than 1 lb

• Test Result 7oz.

• Less than 1mm thick

• Test Result 0.7mm

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Technical Constraint/Test ResultCurrent Draw

• 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

• Test Results Current Varied
• Max Current 90mA
• Average Current 44-50mA
• Correlation between USB data stream and current

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Technical Constraint/Test ResultVisibility

• 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

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Technical Constraint/Test ResultSoftware
Functionality

• Chords must match LEDs
• Metronome must be consistent
• Audio samples must be accurate
• Confirmed in field tests

13
Technical Constraint/Test ResultResponsiveness

• Under 1 ms delay
• Appear instantaneous
• Tested in software timing
• Transmit minimal data
• Code optimization

14
Practical ConstraintEconomic-Bill of Materials
Total Cost 49.39
Costs based on the purchase of 100 units
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Practical ConstraintManufacturability

• 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/PackagingSoftware

• 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.

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Design Refinement/PackagingLED 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

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Design Refinement/PackagingUSB Communication
System

• Used SMT microprocessor-smaller board

20
Video of Light Leader
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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?asinsearchB00
  005OCKA
• 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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• ltspace fillergt

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Prototype Design Software

• Text-based tablature
• Scrolls two spaces
• Data streaming over USB
• Use of pipes
• Simple user options
• Audio and timer settings

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Prototype TestingSoftware

• Verify tablature and LED accuracy
• Visual comparison
• Verify USB data
• Oscilloscope and sniffers
• Verify audio correlation
• Hands-on testing

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Prototype DesignLED Strap

• Attachment of the Velcro to FPCB
• Soldering LEDs and wiring connections
• Assemble connection pins for strap to USB
  communication system
• LEDs protective covering

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Packaging Plan

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

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Prototype TestingLED 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

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Prototype DesignUSB Communication System
Firmware

• Schematic
• Transistor Biasing
• Firmware

USB
STRING SELECTORS
FRET SELECTOR
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Prototype TestingUSB 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