Gibson Guitar Robot

GIBSON GUITAR ROBOTYet another application of microcontrollers…

Team – Sleeping ModeAbhishek Anand - BG107Cs003Abhishek Mishra - BG107CS004

Akash Gupta - BG107CS010Manish Kumar - BG107CS062

Paramjeet - BG107CS080Subhash Choudhary - BG107Cs119

The Problems of a Guitarist

• Tuning mechanism hasn’t evolved much.

• Each peg is still turned manually to get the right tone.

• Factors like heat change the tone of strings.

• Stretched strings are very tough to keep in tone.

• People rely on software like Guitar Tuner Pro.

• Inconvenience.

• Lot of time gets wasted.

The Solution

Gibson Guitar Robot

The Solution

Gibson Guitar Robot

• End to manual peg twisting

• Automatic tuning in seconds!

• Accurate results

• Uses Microcontroller and Motors

Features

Gibson Guitar Robot

• Dynamic Tuning

• Read and Right

• Speed Dial

• Switch Beats

• 200 tunings between battery

charges

The Setup

The Setup

MCK – Master Control Knob• adjusts volume – normal function• on pull – becomes tuning selector• LEDs show status of tuning• shows battery level (1-10)

The Setup

Charging System• 2.4 V NiCd battery pack• Stepped up to 12V to power other parts (motors etc)• 90 minutes full charge•200 tunings per full charge

The Setup

Powerhead Locking Tuners• Rohm's BA6845FS motor drivers• Rotates to pull strings for tuning• RPM is reduced by ratio of 500:1• also works for manual tuning

The Setup

Piezo Pickups• detects frequencies• feeds signals to Data Transmitting Tailpiece• the signals are multiplexed into C8051F120 MCU’s Analog/Digital input

The Setup

Data Transmitting Tailpiece• contains Silicon Labs C8051F120 12-bit MicroController• uses crystal-derived reference frequency, to decide if string’s frequency is flat, sharp or on pitch.• depending on the string’s frequency, controls the motors in tuners

Silicon labs C8051F120 12-bit• High Speed 8051 uC core

• 100 MIPS Mixed-Signal with 64 I/O Lines

• 5 Timers + 1 Watch Dog Timer

• 128K Byte In-System Programmable FLASH

• 256 Bytes RAM

• 8K Bytes XRAM

• 2 UARTS

• Supply Voltage 2.7V – 3.6V

Working

#1 Master Control Knob is pulled up• this enables the C8051F120 unit• lets user load a preset

Working

#2 Pickup detects frequencies• converts string vibrations into frequencies• multiplexes all 6 string frequencies• feeds them to C8051F120 ‘s input

Working

#3 Tailpiece (MCU) analysis• C8051F120 MCU analyses the signals from pickup• decides which string to tune• decides how much to tune on the basis of

• preset loaded• temperature

• sends signals to Rohm's BA6845FS motor drivers

Working

#4 String Tuning• Rohm's BA6845FS motor driver controls the tiny servo motors attached to each string• Each string is rotated unless it reaches desired frequency

Precautions

• Make sure no two strings touch each other – might lead to short

circuit

• Make sure MCK is not pulled when while guitar is in storage, this

would drain out the battery completely

• While strings are removed, make sure that Tailpiece (MCU)

doesn’t move, this could damage its connectors

• Don’t turn the pegs manually while MCK is pulled, i.e. Robot is

ON

Conclusions• We saw, how a microcontroller helps in automating difficult

tasks.

• A microcontroller makes redundant tasks easier.

• Gibson Guitar Robot is able to take intelligent decisions by help

of a microcontroller.

• A microcontroller adds more functionalities and values to a

product.

Thank You…For more information -

• http://www.gibson.com/robotguitar/guitar.html

• http://www.eetimes.com/showArticle.jhtml?articleID=207400963

• C8051F120 Datasheet

http://www.datasheetarchive.com/C8051F120-datasheet.html