Hi, i have a pixhawk controller and first installed it without any GPS,
The althold mode works great indoor. Very stable. But after installing GPS althold is a mess. Jumps from floor till ceiling. Monitoring altitude it fluctuates and looks like gps alt while barometer raws pressure is solid as a rock. Even if althold mode is selected. Removing the GPS and reflashing althold works ok again..
I assumes Stablelize and althold modes do not use GPS.
It is a M7N gps with compass.
Is it possible i2c gives problem?
Replies
You need to set AHRS_USE_GPS to zero if flying indoors
I read about it.
However it isn,t very smart if baroalt is more stable than gpsalt.
Or use baro exclusively in AltholdMode and GPS in loiter and poshold. As this is already stated in the flightmode explanation.
It also would be a nice option to switch ON/OFF AHRS_USE_GPS by switch. So user can select INDOOR/OUTDOOR Mode.
Or have AltHold Mode do this automaticy.
Seems not to much to ask for.
To fly indoors autonomously you need more sensors, like optical flow and sonar or other height device. baro alt suffers from air pressure changes in rooms from doors being opened/closed to air-conditioning and heating fans being enabled. Optical flow and sonar have issue with simple thing like somebody walking under them, the height changes!
Transitioning from indoors to outdoors is also difficult to handle. as GPS does not work well, in or near buildings. Determining when you are in or near a building is also not easy (see how many people report they have a good lock indoors which the GPS reports, but is actually highly unstable as you have experienced)
What seems like 'not to much to ask' is 100s and 100s of hours and development time.
Adding a option to a GCS to toggle the AHRS off more readily is good suggestion. With the caveat flying outside requires it to be reenabled!