Pid for drone

Hi everybody . I'm working on a school project and we 're building up a drone controlled by arduino . Howvere we are not able to find the correct pid parameters . I want also to ask if my sketch is correct: when I register an roll (or pitch ) angle I get down two motors of pid value, and so on . It s correct ? Thank you

PID tuning is typically done by trial and error, athough there are ways to estimate the values from
measurements of the system response. Googling "PID tuning" is a good place to start, my summary
would be:

start with P, edge it up until oscillation, back off
Add a very small amount of I to improve accuracy, but note I is very likely to cause oscillation
unless P is reduced.
D can be added to reduce instability and allow both P and I to be increased (speeding up system
response). D always adds noise/jitter though.

And for a drone, mount on a pivot for testing, do each axis independently at first.