Alexandra V. Maska

1
Guitar Tuner Project

• Group 10
• Alexandra V. Maska
• Daniel Kitts
• Stewart Robertson

Fall 2006 MENG 483 Project
2
Outline

• Introduction
• Overview Diagram
• Design
• Mechanical
• Electrical
• Software
• System Assembly
• System Testing
• Thanks and Acknowledgments
• Cost Report
• Conclusion

3
Introduction

• Purpose
• Create a tuner that will accurately tune an A
  string on an electric guitar
• Design Considerations
• Integrated Peg Turner vs. LED display
• LabView vs. Digital Signal Processing chip
• Humbucking Single Coil pick-ups vs. microphone
• Design Solution
• Utilize the cheap and efficient ability of
  LabView to operate Fast Fourier Transforms in
  tandem with the available sensor (Humbucking
  Single Coil pick-ups) on the electric guitar.

4
Overview Diagram
Guitar- The Godin Exit 22 is both our source of
input data as well as our sensor. Signal
Conditioning- The LabVIEW Elvis from National
Instruments is our source of signal conditioning,
undertaken through the use of Fast Fourier
Transforms to convert the analog guitar input
into a discrete and comparable time signal. DA
Board- The digital to analog signal processing is
undertaken through the use of the Eclipse
software platform. MRK Board- The results from
the running of the C code are displayed along the
eight LEDs on the MRK board. Different LEDs
represent in tune, sharp or flat.
5
Mechanical Design (Sensors)

• Sensor Options
• Guitar pick-ups
• Microphone
• Pick-ups (Sensor Decision)
• Single-Coil pick-up
• One permanent magnet coiled with copper wire
• Humbucking (multiple coil) pick-up
• Multiple permanent magnets coiled thousands of
  time with copper wire

6
Mechanical Design (Actuator/Output)

• Actuator Options
• Stepper Motor
• Light Emitting Diode (LED)
• LEDs (Actuator/Output Decision)
• A semiconductor device that emits incoherent
  narrow-spectrum light when electrically biased in
  the forward direction.

7
Electrical Design

• Electrical Design Options
• DSP (Digital Signal Processing) Chip
• LabView
• NI ELVIS
• Electrical Design
• NI ELVIS
• National Instruments Educational Laboratory
  Virtual Instrumentation Suite
• Available in the Mechatronics Laboratory.
  Specifically designed to be used in an academic
  laboratory setting, such as this project.
• Used with LabVIEW to perform Fast Fourier
  Transform.
• LabVIEW 7.1
• Laboratory Virtual Instrumentation Engineering
  Workbench
• Used in MENG 405L, in tandem with ELVIS removes
  the necessity for the DSP chip
• DSP
• While DSP chips would perfectly suit the needs of
  the project they are costly (395) and this makes
  them nearly impossible for the team to use.
• Amplification
• National Semiconductor 411NC
• Gain of 100
• Using a 100 kO resistor and a 1 kO resistor

8
LabVIEW Block Diagram/Front Panel
9
Software Design

• Code written in C/C and compiled in Eclipse
  IDE
• Logic flow diagram

10
System Assembly

• Guitar
• Humbucking Pick-ups
• Op-Amp
• LabVIEW/ NI ELVIS
• MRK Board
• LED Display

11
System Testing

• Signal
• Too weak by itself
• Inverting Amplifier w/ 100 gain
• LabVIEW
• NI ELVIS signal generator
• Code
• Interrupt Service Routine
• Total System

12
Material Cost and Total Expenses
MRK Board costs less than 150.00 Humbucking
pickup costs 100.00 Guitar cables cost
20.00 NI ELVIS package costs
1,329.00 Guitar costs 150.00 Assembly/Man-
hours 70.00 Estimated Total Costs
1,820.00 Actual Costs 0.00
13
Acknowledgments

• TAs
• Jon Berg
• Hakan Cakan
• Jason Matthews
• Professors
• Dr. Zagrai
• Mr. John Marshall
• Dr. El-Osery
• Colleagues
• Jordan Warton
• Mechanical Engineering Department

14
Conclusion

• Mechanical
• Developing an understanding of sensor types
  utilized in everyday life
• Electrical
• Unification of laboratory experience both in
  Control Systems and Mechatronics
• Software
• Practical use of logic statements, using
  programming techniques to de-bug

15
Questions

• ?