VOXLCAM on COPTER 4.2 issue


You will find attached log for simple viso test using voxlcam and moving drone by hand.

As you can see, just when started, after “set ekf origin there” if we slide from front to back, from left to right and from bottom to top, the data sent by VOXL match well with the EKF forecast (pos and vel). and the position seen on mission planner match perfectly the reality.

On the other hand, as soon as we turn on our Z axis, the orientation works well but an error appears on the speeds, which do not correspond at all to the position sent.

It seems to me that there is a big mistake in the ardupilot code.

voxl sends positions and velocitys relative to the EKF origin point (which is earth fixed frame)

while ardupilot expects from voxl positions relative to the ekf origin (earth fixed frame) but speeds relative to drone’s fixed frame!

suddenly as long as we are oriented as originally, everything goes well, but as soon as we change orientation, nothing goes and ekf goes into error because the pos do not match to the vel send by voxl frome the ekf point of view…

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@ppoirier @rmackay9 @tridge

Can you tell me if the error come from ardupilot or from voxl ?

what expect ardupilot viso voxl type ?

does it expect earth frame vel/pos from voxl?
or does it expect drone frame vel and earth frame pos?

This issue seems to be simple to resolve if you reply.

thank you so much.


This is the link to @tridge PR , that is all the information I can provide atm:

Hi @kuspower,

Sorry for not seeing this message. I received a VOXL camera last week and during testing found the same bug that you did. We’ve got a fix that is going into master within the next week and then I hope to release it in Copter 4.3.2.

Here’s a new wiki page for the VOXL camera including a video at the bottom showing it working.

Thanks again for the report and sorry for taking so long to resolve it.

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Thank you for have tryed it :wink: and thank you for the report!
I will try it asap and feedback to you

Maybe you can help me on this post: