@ChasinSpin

Yes, Angle approach (with sticks centered) and taking a value whenever that happens would be one approach. Also in Pos Hold mode, monitoring for motor imbalance would be another approach....

In ArduPilot, they estimate the drag coefficient by using the mass / estimated area: https://ardupilot.org/copter/docs/airspeed-estimation.html, which could be used for the more complicated method. I think both are good solutions.

> If you wonder how I know it works. I use it with the programming framework and custom OSD. With a table derived from each of my individual quads. It...

Re: 2. It's common to hook up a drone via USB when configuring on the bench. There's a use case for No Telemetry and getting the telemetry status via OSD,...