[phdelightful]

It’s far from what I do now, but as an undergrad I built an automatic guitar tuner. It had a PIC32 microcontroller that read the sound waves on GPIO pins and did some cross-correlations to figure out the frequency (sort of a poor man’s FFT, but faster since it was less general). It used an FPGA to drive a stepper motor to turn the guitar pins towards the correct frequency. Code was all C and Verilog.

[hathchip]

This sounds awesome.

How does it work exactly? Does the use pluck the strings while the machine turns the knobs?

[ben7799]

Theoretically, but Gibson made these and it was a real failure in the market to the point they even destroyed a lot of the stock of guitars they couldn't sell.

It might raise from the dead with a non-traditional guitar design like a headless guitar where the mass of the automatic tuners could be hidden inside the guitar body.

[CoolestBeans]

Electronic self-tuning machines are still a thing, its just returned to totally aftermarket. Its just too niche and really mostly useful if you use a lot of alternate tunings in a set and can't bring multiple guitars.

[eps]

Lots of music shops use them too.