Guitar tuner using cepstral analysis and fuzzy controller on arduino board

Cepstral analysis and fuzzy controller is used to design an automatic guitar tuner on Arduino micro-controller. Signals from an acoustic guitar are fed into a system running MATLAB. Fundamental frequency of the played note is evaluated using cepstral analysis and is compared with desired set point. Frequency difference between the calculated frequency and the set frequency is used as an input to a fuzzy logic controller that generates a corresponding output as per the mentioned rules. This output from Fuzzy controller is used to generate a PWM signal with varying duty cycle. Output of the PWM signal is fed to a motor driver circuit which amplifies it and rotates the motor in appropriate direction with varying speed. This adjusts the tension in the string which results in change of frequency of the string to bring it to the desired pitch. System has been tested and verified for ‘A’ note and successful results were obtained with marginal offset. This paper highlights the use of cepstral analysis and arduino board for designing an automatic guitar tuner.