esc: clarify RPM/command direction meaning #64
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Reverse should only be used for reverse thrust, not simply a motor that happens to be spinning counter-clockwise.
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Reverse should only be used for reverse thrust, not simply a motor that happens to be spinning counter-clockwise.
Some ESC vendors get the RPM feedback backwards when configured in reverse direction, so flight stacks need to be aware; not sure how wide-spread the problem is. I have confirmed that latest AM32 using DroneCAN behaves correctly here: reversing the motor direction in its configuration does not reverse the RPM sign.
I had an additional comment about how an ESC which is running in reverse in response to a supported negative bi-directional command must report a negative RPM but AM32 does not do this. I am not sure where the limitation is but IMO this is a bug, and probably a more wide-spread one.
I further wonder how we should define the motor angle in the extended status. I presume it should be that increasing angles are clockwise? So it would swap if you reversed direction in the ESC, and always match the physical angle. But I am not sure what's best here and don't own any ESCs with angle sensors. We do need to add a note that the percentages are absolute.