ECE 110/120 Honors Lab Section : Guitar Auto-tuner

            Statement of Purpose:

The guitar auto-tuner is a device that is designed to automatically adjust tuning pegs according to measured pitch. A microphone (like in a tuner) would pick up a pitch from the guitar string being strum, and would transmit that value to an Arduino. If the pitch is sharp, (higher frequency than desired) then a motor would spin the tuning peg to lower the pitch. As expected, if the microphone pitch is lower than desired, the motor would spin the tuning peg to raise the pitch. This guitar auto-tuner is meant to remove the arduous, tedious task of tuning a guitar

            Background Research:

The standard way to tune a guitar is to attach a tuner, strum a string, read the tuner output, and manually turn the tuning pegs to match the desired pitch. By the time the tuning peg is adjusted, the vibration from the guitar string has already partially diminished. The person tuning would then have to strum the string again, and repeat the entire process over again. After the first string is finished, the whole process is repeated for each of the (6) strings. The auto-tuner is meant to remove the entire process. Future research will be conducted on the methods tuners use to sense frequencies.

           Block Diagram:

            Parts:

• Arduino Zero
• 10k ohm trimmer potentiometer
• TLV2462 (I/O operational amplifiers)
• 100k ohm resistors
• 47k ohm resistors
• 100n farad capacitor
• 3.5mm jack
• Microphone to Stereo 3.5mm jack
• Clip
• Motor
• Tuner body button
• Customized clamp
• Modified tuner body
• Battery

           Possible Challenges:

If the tuner microphone is not able to output read frequencies as simple values, then it will be difficult to code the logic in the motor. It may be difficult to make this a small, compact body that will fit on a guitar. It's dangerous if there's a glitch anywhere in the system: if the machine twists the guitar's tuning peg too far a certain way, the strings may snap. There may be other malfunctions with reading frequency from the guitar, such as when multiple strings are plucked, or (if a microphone is used) too much background noise.

            Weekly Journal

   February 23rd, 2017

Finished block diagram and further researched parts based on frequency meter schematic. https://www.arduino.cc/en/Tutorial/SimpleAudioFrequencyMeter

   March 2nd, 2017

Nearly finalized parts list and ordered parts.

   March 9th, 2017

Conducted research on open source Arduino programming (Arduino Zero).

   March 30th, 2017

Received parts and finalized parts list and ordered last parts.

Started to work on the breadboard, placing parts and connecting pins.

   April 6th, 2017

Completed breadboard circuit.

Started working on logic code for Arduino.