[phdelightful]

As an undergrad I made a guitar tuner using a PIC32 microcontroller to do time-series correlation to figure out the frequency (FFT was too slow for real-time) and a state machine embodied in a stratix FPGA to control a stepper motor to turn the pegs. A different era of “mobile app” I guess.

[icapybara]

Correlation is calculated using FFTs, so wouldn't that be just as slow?

[karmakaze]

Computations can be reduced if you only care about frequencies near 6 particular ones (and maybe some harmonics).

[xani_]

You'd get shit tuner if you do that. Ain't nobody got time to define scales on a fucking tuner

[karmakaze]

There's only 12 per octave, way fewer than doing FFT for all frequencies in Hz steps.