External Compass Questions

[agamirzov (Evgeny Agamirzov)]

Hello George,

Thanks for the feedback.

@george.staroselskiy

This is an implementation detail that shouldn’t really be depended on. AFAIR, external compasses have been set as COMPASS 3 for quite some time.

I see. Nevertheless, even the latest version of MP says that it should be COMPASS 1. This is a little confusing.

@george.staroselskiy

I don’t think it’s faulty. The values that are getting read look OK. Have you recalibrated the compass after changing orientation? It’s an essential step (we’ll update the docs). After everything’s calibrated, all three compasses should report very similar readings in logs.

As you suggested, I have re-calibrated the compass after changing the orientation and my copter has become much more stable. Before I had issues with compass EKF going to the red zone when rotating the quad (changing YAW direction). Now it is gone! Thanks!

Though, I wonder why the arrows on my external compass are drawn that way. Should one trust these arrows in general or the orientation has to be determined experimentally?