PID Autotune

[aamott]

Is your feature request related to a problem? Please describe.

Getting PID values right can be a struggle. It involves constantly reuploading the code and hoping your changes worked well.

Describe the solution you'd like

Some kind of autotune method like what Marlin uses. Number of cycles could be configured in configuration.h or in the menu. Either would fulfill the need.

Additional context

Might be good to base the autotune process on Marlin's code.

[alextrical]

I have yet to find a PID autotune library I'm happy with, that comes anywhere near close to the functionality of the one build into marlin. If you are looking into porting that into a stand alone component, I'm more than happy to offer my time towards helping port it to a Arduino sketch/library

[aamott]

Porting Marlin's PID is a great idea. I've got to fix a few usability issues with the configuration before I work with PID and autotune, but if you want to look at that, it could be useful both in and out of this project, especially if it's kept flexible enough to use multiple heaters.