I'll look into this later this week. Thanks for getting back to it.

the gimbal is mounted "upside down" which means the camera is above the gimbal.

I don't think this is true? In all the marketing material and documentation and menus, the "normal" orientation of the gimbal has the camera above the handle and control unit. In most drone applications the camera will hang below the handle and control unit, which is why we provide the upside down mode, correct?

As for the roll/pitch being reversed, I'm not sure what's up. The code to retrieve the data as it's written directly contradicts the documentation at the top of the file and the spec available here. But if it works for you there must be some gimbals which are reversed? I'll double check this too.

Might be best to just make everyone update.

@tpwrules,

Txs for the feedback and offer of testing. You may be right about the definition of "upside-down". I'll check with another user I know about what he thinks is rightside-up vs upside-down.

Regarding the testing script in the branch in the old issue, I get poscontrol len: 19, att len: 26. These sound like they match expectations.

The script in this branch works fine with my gimbal. But the roll and pitch axis reports are for sure swapped. If I set DJIR_DEBUG=2 and move my controller's roll input (function 212), then the gimbal roll axis moves, but the pitch number changes in the debug output. Same thing if I move function 213, then the pitch axis moves, but the roll number is what changes. Yaw seems okay. I only did testing so far in right-side-up mode, with the camera above the handle/controller.

Again, the protocol documentation contained within the script itself and the PDF from DJI suggests the interpretation my gimbal uses is correct and the script code is wrong. You say your gimbal moves correctly, did you check that the reported data is in fact correct using the debug option? Can you remind which firmware your gimbal is on? Mine is 01.05.00.20.

@tpwrules,

Thanks for the testing and feedback. As hard as it is to believe, I think DJI had a bug in the angle reporting for roll and pitch in the legacy firmware (they were swapped). I've updated the PR so that for the "latest" DJI firmware it uses the correct order.

Maybe you could comment whether you're happy with these changes? That'll clear the way for merging I think. Txs again.

I personally would like to see support for the legacy protocol dropped completely. Updating is slow but not hard; the user has to have hooked up the app to activate the gimbal in the first place. We are also assuming whichever version updated the packet length is whichever version fixed the reporting bug, which is hard to determine.

Aside from that comment nit, I'm happy with these changes if you're happy with the additional complications of supporting multiple versions.

@tpwrules,

I think it's so easy for us to keep supporting the old firmware that we should.

I agree re the comment but I'll do that in the future I think in order to get this in now that it's functionally correct.

@tpwrules Randy has committed to adding coimments on the roll/pitch issue in a follow-up PR.

We discussed removing legacy protocol support but Randy made a spirited argument that in this case it's a very small amount of work to support the older firmware and there's no other drawback in doing so.

We do enforce minimum firmware version on some camera drivers, but in this case we don't need to - yet!

Thanks for looking through this PR, we do appreciate the reviews :-)