Arming in altitude hold mode

I build a copter and I think that I have issue with arming the copter in altitude mode. When I arm in this mode the motor not turn on. Someone could help me and tell me if it is fine?

Have you used the Motor Test in MissionPlanner?
What happens when arming in Stabilise mode?
What have you got set for these parameters
MOT_SPIN_ARM
MOT_SPIN_MIN

Yes I did a motor test and I calibrated this parameters. In stabilise mode everything work wonderful.

MOT_SPIN_ARM = 0.04
MOT_SPIN_MIN = 0.07

I would just increase those a bit since they are very low

MOT_SPIN_ARM,0.06
MOT_SPIN_MIN,0.09

and see if that helps

Also you could set LOG_DISARMED = 1 and try arming in AltHold again then post that .bin log here.
Then after you set LOG_DISARMED = 0
That we we can see what’s happening.

Thanks men I have more 2 problems maybe you can help me:

  1. EKF primary switches in during the flight in stabilise mode.
  2. I want to get a FFT of gyro pre and post filter from dataflash log. I change the INS_LOG_BAT_OPT = 4 but I can see just the pre FFT when I read the dataflash log. do you know why? I think that I have vibrations that cause to EKF switches and I want to config harmonic notch filter.

What do you think?

What version of firmware? And did you also set this:
INS_LOG_BAT_MASK,1

Yes, INS_LOG_BAT_MASK = 1, version stable 4.2.3

Update to latest Stable version. I don’t think Option 4 is supported in 4.2.3.

When I worked with the last version 4.3.6 I have this problem “PreArm: Baro: GPS alt error 5850m (see BARO_ALTERR”

OK - known issue!
Install the Pixhakwk1 firmware if not already - all your current parameters will be retained.
Then set
BARO_OPTIONS,1

The problem is some of the “manufacturers” of the cheap/clone Pixhawks substituted the baramoter part.

You can put INS_LOG_BAT_MASK = 0 since we wont need it now.