Hi all, I am still new to arduplane and getting my mini talon setup. I am using a Pixhawk 4 Mini and I would like to mount the GPS puck facing the rear of the plane due to the layout I am going with. I have also read that compasses are not needed when using Pixhawk/Arduplane in a fixed wing so I have them disabled.
My questions is how do I go about setting the orientation of the GPS in MP? Or does the GPS self-orient once the plane is flying based on the direction it flies? Any input would be appreciated.
The GPS has no specific orientation. It detects heading by the direction it is moving. A compass module’s orientation is important and Ardupilot has a parameter to allow you to orient it in a non-standard direction. But GPS — does not matter.
So, if you have a combination module with GPS and compass AND you have the compass enabled, you would need to use the corresponding COMPASS_ORIENTx parameter to indicate to Ardupilot the orientation of the compass.
The compass isn’t needed to fly Plane, but that doesn’t mean you should disable it if you have one. It should perform better in windy conditions if it knows where the nose is pointing.
Also there is always the chance your GPS fails or comes unplugged, at which point it will switch over to the compass and try to dead reckon. This could make the difference between RTLing your plane or losing it. I’d say leave them turned on.
But I do like the added safety. I have mounted my GPS/compass rear facing and will go into the parameters and orient it properly. So assuming I enable both the internal compass of the Pixhawk 4 Mini and the external compass on the GPS/Compass, the external compass would be COMPASS_ORIENT not COMPASS_ORIENT2?
Follow this http://ardupilot.org/copter/docs/parameters.html?highlight=compass_orient down to the COMPASS_ORIENT and COMPASS_ORIENT2 parameters and you will see that they ONLY apply if the compass is external. The last sentence under COMPASS_ORIENT2 states “NOTE: For internal compasses, AHRS_ORIENT is used”.
So, COMPASS_ORIENT is for the external compass but AHRS_ORIENT is used for the internal.