It seems like PID controllers and tuning PIDs requires an advance degree from a multicopter university. The numbers in “Proportional”, “Integral” and “Derivative” columns for each line from “Roll”, “Pitch”, “Yaw” to “Level” make up a cryptic graph or chart standing between you and flying a solid, responsive, “locked in” mini quad like Charpu!
There are a plethora of videos on Youtube explaining the math behind PIDs, what to look for, how to tune, etc. It’s overwhelming. This weeks’ Video of the Week is one of the best explanations on how to tune your mini quad. And take it from me, I’ve watch hours upon hours of Youtube videos trying to crack the code of PID tuning.
I also found this explanation of PIDs on the RCGroups forum recently posted by user Pyrock.
…The P setting will improve its ability to hold steady up to a point at which is will start to shake. Once you’ve increased the P to the point of it shaking, just back off until it’s solid. You’re “I” setting sets your quads ability to correct for unwanted movement. It could also be your “I” setting. If your “I” is too high, it will over correct and give you a bouncing affect when outside input is introduced such as wind. A sign that your “I” is too low is if it drifts or vibrates while you’re flying. Your “D” setting allows it to be rock solid after you give it control input (not correction input due to wind or outside forces which is your “I”). Too much “D” and it will be slow to respond to stick input. Basically it is either your P or you I setting. I hope this helps.