Piezoelectric Guitar Tuner

Abstract: This bachelor thesis in Mechatronics account for the process of constructing an automatic guitar tuner by means of a piezo-electric sensor, a stepper motor and Arduinobased control. The E4 - string on an acoustic guitar was used as a proxy for tuning any other possible guitar string. The accuracy and tuning-speed of the construction was examined through physical experimentation. Accuracy was measured in terms of the average distance from a piezo calibrated frequency value. The tuning-speed was appraisedby counting the number of times a guitar string had to be plucked before the motor stopped within an acceptable tuning interval. The automatic guitar tuner were able to reliably get the E4 - string in tune by plucking it once within an interval of ±2 Hz and +3.8 cents and −5.1 cents from the theoretical value. The average error was −3.4 cents from the targeted value.