Does anyone know why my barometer (altitude) would be fluctuating so greatly when the aircraft is not even flying?  I have it on a table in my house connected to the mission planner software.  When I first connected the aircraft to my laptop I saw the altitude was about 5.  After about 10-15 minutes of watching it, it has now climbed to 18.18.  Any reason why?  I have the same problem while flying.  It goes up, then goes down, so I am always fighting it on the throttle.  I assume the sensor is causing this problem. 


I have tried covering the barometer with different things as I read on these boards.  Tissue, black e-tape, both tape and tissue, a plastic cover over the entire apm, nothing seems to help the aircraft from dropping and rising while in flight.  I am thinking about getting a wookong which my friend recommended.  His hexa seems super stable even without a gps lock indoors.


Any thoughts or ideas?






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I'm having the same issue. In sensor test mode im getting -100cm to +50 cm while the board is at rest. I emailed 3D robotics last night, I hope this is normal and not a defective sensor.


Also, why is the raw temp changing but the actual temp is not?  Is it very high precision?  And why does it always say 279/100deg c?  There is no way the chip is that hot.


Yes this makes no sense to me? Im still waiting on a answer from 3D Robotics on this issue. I have the 2.5+ which they claim to have an improved barometer. Have you tried Loiter Mode? I'm afraid to. In Alt Hold the motors seem to cut out then pulse for a second at full throttle then repete this as it loses elevation. Im starting to wonder if I made a mistake not going with DJi.



If you have sonar, try disabling it. Seems to be causing issues with alt hold.

Also, check your z axis accelerometer.......should be -9.8 ( plus and minus 5 max)

with 2.9.1

If outside plus minus 5, too much vibration. You will have to dampen the apm board.

Hope this helps you out.


We are both doing these tests while the craft is sitting on the ground so vibration should not be an issue. I do not have sonar, and my apm does the same thing with barometer fluctuation.

I guess the sensor is OK after all. I read where the throttle had to be right at 50% when switching to Alt Hold. I tried this method early AM before work. It worked amazingly well. After that I got up the nerve to try Loiter Mode, it worked perfect! My little quad stayed locked in place about 50' above my head for about 3 mins hands off the controller :)
I also experienced the same problem, so I have the intention to replace the pressure sensor / barometer? due to the barometer, my Multicopter not want to turn off the throttle or landing, perhaps because the barometer detects still at altitude.

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