[jopizio]

I've used this successfully for some hardware projects: https://pidtuner.com/#/

[jcgrillo]

That looks like it's using the step response, which is on for an offline tuner but it wouldn't work for online tuning. Think of an automotive cruise control--to measure the step response the controller would have to floor it, which wouldn't be safe. I'm looking for something that slowly, continuously optimizes the tuning parameters as the controller is running.