Running Pixhawk 4 AP, Arducopter V3.6.9, Mission Planner 1.3.66. Both compasses calibrated with offsets in the green. When moving the frame around unarmed, I randomly get the “3 rising tones” followed by “3 lowering tones” No errors I can see get reported, What are these 3 tones telling me? I went through the logs looking for errors but cannot find anything. EKF and 3DLock are both white when it happens. It’s happening less frequently now, but after "3 lowering tones it will not arm. No error messages compass or accelerometer are showing, yet I do see the red led flicker a bit even when its armable. Any ideas? I’d sure love to know what the 3 rising/lowering tones means. Under what parameter(s) in the log would this be shown under?
Three rising tones means transitioning to armable.
Three descending tones means transitioning to not-armable.
You appear to be moving between the two. Notionally this could be caused
by the armable tones themselves, depending where you have the buzzer
mounted - but that’s unlikely.
If you try arming while not armable the vehicle should tell you why it
can’t arm using statustext messages.
When it gets into this weird mode where it’s transitioning back and forth between armable and not-armable there are no error messages. Once it starts happening, I have been able to isolate it to the pitch axis when changing from slightly above horizon to slightly below. What else in the logs can I look at to give me more clues as to what is going on? One other thing to note is that the red FMU led on the pixhawk 4 is winking faintly even though Mission Planner shows EKF and GPS: 3D lock as white
Even though the GPS shows a solid 3D lock that is not the only thing the code is looking at to determine if it is stable enough to arm.
The biggest contributor to this effect, and yes, I have encountered this, is the vertical or horizontal velocity being reported by the GPS.
There is a value being reported in the logs which is explained here that might shed some light on it.
Open the ekf on mission planner hud and move frame around, watch at the compass bar, if it raises in the red thats your prob. Maybe picked up a wrong axis in the calibration, in case do calibration again.