Dustin House

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A Self-Tuning Acoustic Guitar

• Dustin House Chris Moorman
• John Mouser Brian Neill Jack Skinner

Advisors Dr. Juliet Hurtig Dr. John-David Yoder
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Problem Identification

• Defining own sound
• Creating tuning schemes
• Difficulty with accurate tuning
• String breaks during a performance
• Existing tuning methods require the user to do
  all of the work

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System Overview

• Recognition of a plucked string
• Fundamental frequency is recorded
• The tension in the string is adjusted to obtain
  the desired frequency
• Motor is used to turn the tuning peg

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Components

• Transducer
• Motorola 56F826EVM DSP Board
• MC68HC12 Microcontroller
• LCD, Keypad, and LEDs
• Servo Motor
• Spur Gears

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Hardware
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Hardware
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Software
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Electrical System

• Capturing Note
• Hexaphonic Pickup
• Microphone
• Servo Control
• Voltage Regulator
• Power Supply
• User Interface

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User Interface
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FFT Comparison
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Mechanical System
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Mechanical System
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Mechanical System
SERVO MOTOR
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Mechanical System
SERVO MOTOR
GEARS
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Mechanical System
SERVO MOTOR
GEARS
TUNING PEG
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Project Expenses
Table 1. Component Budget
Part Total
Ribbon Cable 5.00
LCD 19.89
Servo Motor 6.95
Keypad 16.95
Part Total
Microcontroller 100.00
DSP Board 351.00
Gears (2) 30.00
Miscellaneous Parts 100.00
Prototype Cost 629.79
Cost of Engineering Time 22,500
Total 23,129.79
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Results

• Electrical design completed
• User interface
• Hardware for servo control
• Power supply
• Mechanical system implemented
• System mounted
• Gear cover

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Results

• Software design
• Keypad, LED indicators and LCD
• Motor control
• Issues with servo motor control
• Accuracy
• Consistency in tightening

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Future Considerations

• Tightening string
• Gear binding
• Torque rating
• Frequency detection code
• Writing to flash memory
• Meshing with completed code
• Various tuning schemes

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Acknowledgements

• Dr. Juliet Hurtig
• Dr. John-David Yoder
• Dr. Les Thede
• Dr. Khalid Al-Olimat
• Dr. Srinivasa Vemuru
• Mr. Brad Hummel

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Questions?