11/25/02

Auto Tuner

Brian CrosbyBrian Crosby

11/25/02

Background

Manual tuning a string instrument Manual tuning a string instrument to reference tones take skill and is to reference tones take skill and is often a time consuming and error-often a time consuming and error-

prone process.prone process.

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Problem

To develop a portable system that To develop a portable system that automatically tunes a string automatically tunes a string

instrument to its standard tuning instrument to its standard tuning quickly and effectively.quickly and effectively.

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Solution

Use a servo motor to turn tuning keysUse a servo motor to turn tuning keys Tuning with plucking motionTuning with plucking motion

Smart pluck softwareSmart pluck softwareProgramming learns Programming learns

• Tuned in Three plucksTuned in Three plucks

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Three Pluck Smart Software

11stst 2 2ndnd 3 3rdrd Plucks Plucks Motor movementMotor movement Signal FeedbackSignal Feedback CalibrationCalibration CalculationsCalculations Final Tuning Final Tuning

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Smart Software First PluckFirst Pluck

Reads input signal then Moves servo motor Reads input signal then Moves servo motor 45 degrees45 degrees

Second PluckSecond Pluck Reads change in pitch and calibrates Turns Reads change in pitch and calibrates Turns

ratio of servo >degrees to Htz.<ratio of servo >degrees to Htz.< Third PluckThird Pluck

Reads difference between reference pitch Reads difference between reference pitch and input, calculates change, makes change and input, calculates change, makes change through use of servothrough use of servo

11/25/02 Brian Crosby

Plucking Concept

Servo Motor

Smart software

Signal activates software

Software sends out pulse to Servo

Servo turns 45 degrees, changing

pitch of string

New pitch is feedback into smart software for analysis and change

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Guitars in Tune

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What does it look like?

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System Overview using Smart plucking software

Microphone

A/D Converte

r

Smart software

High or low

Servo

High

Servo

LowInstrument is plucked three times

Gear System

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What's Next?

More ResearchMore Research Start Writing softwareStart Writing software Choose interfaceChoose interface

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ScheduleFall Semester Spring Semester special events

Week

1 2 3 4 5

Bre

ak 1 2 3 4 5

Bre

ak 6 7 8 9 10

Bre

ak

11 12 13 14 15

ResearchMotorsSoftwareelectronicsGearingBatteriesDesign decide on solutionelectronicsmechanicalinterfacecasingTestinginterfacecomplete system final testBuildwrite softwarecircuit board give Bob schematicenclosureRedesignPresentations presentations

Special events week we are in

11/25/02 Brian Crosby

Any Questions????