Altitude control - Loosing controls

Hi everyone,
I just flashed the latest stable px4 firmware 1.5.4 to my AUAV-X2. Stabilized seems to be okay but if I switch to altitude control I loose controls. Throttle Stick is at mid position when switching to altitude control and the copter shoot up in the air, lowering the stick to zero doesn’t help and the copter is not descending. It is not controllable at all with standard setting.
What do I need to do to get it work. Is it a flight controller problem?

I have an exact same frame with a pixracer 1.5.3 and it seems to work perfectly fine there.


Hard to tell without a log. 1.5.3 and 1.5.4 are the same version with just the tag renamed. Are you using master by chance on one of them?

What we changed on master is that the hover throttle param is now relevant and you need to set it for optimal performance. It should not shoot up uncontrollably though.


I would love to give some logs, but it doesn’t write it. I just flashed ac 3.4.4 from QGroundControl and there was no problems writing logs. After flashing px4 1.4.4 Master it did not write any logs. Why?

I need some more altitude tests to give some more details.

I couldn’t switchto a gps flight mode, why? Only whene The copter was not armed, then I could change the flightmode. In Ac and Px4. Strange!

is it possible that px4 1.4.4 ist not writing logs on auav-x2?

@PKocmoud Can you validate that? Note that we’re not actively supporting 1.4.4 any more - do you mean 1.5.4?

Hi @Lorenz,

The X2 uses the same firmware as the FMUv2. I cannot load 1.4.4 without actually building it. But for the sake of confirmation, I have loaded Master (1.5.2dev) on an X2 and logging works fine. I don’t have it mounted to an aircraft so I cannot actually fly it. But if you have no complaints from other Pixhawk (FMUv2) users then I would suspect a local issue.

Maybe load a current version of the firnware?
Maybe defective hardware?

Logging used to work fine with arducopter and actually with px4 as well. I was surprised that it did not work.
I will flash the latest master and write some feedback. This will be netxt weekend.

I’m using AUAV-X2 with PX4 since 1.2 and I have never experienced any Problem with Log File generation.

How did you mount your controller

On peace of foam or a proper vibration dampner

no I never do vibration damper, it is not necessery.
Not one of my race quad are damped and they fly like a charm with betaflight.
The software has to fix it :slight_smile:

I have meet the same problem,

@Sn0west @cctsao1008 Did you guys manage to solve the issue?
I am facing the same issue on a Helicopter build. Once I switch to altitude mode it either shoots up at maximum speed or crazy roll values and causes a crash.