All parameters set to default by themselves

Copter 4.0.2 already the 2nd time all parameters gone! The first time it was after the update from 4.0.1 to 4.0.2, everything was set up again and wanted to fly today, everything gone… What can be the reason for this? I have to deliver the Copter next week, better go back to 3.6.x?

Hardware is Cube Black on a Kore board.

Hi @webmotions,

Thanks for the report. This problem is apparently quite difficult to reproduce so it’s been difficult to narrow down on the cause. We have a possible fix in this PR that is undergoing peer review.

If you can reliably reproduce the issue then we could give you a firmware to test. Most can’t reliably reproduce it though I think. My understanding is two things are often involved:

  • a power issue with the setup. Perhaps the power provided to the eeprom chip rises too slowly.
  • it happens mostely immediately after writing a new firmware to the autopilot

EDIT: by the way, this issue has been reported on a variety of Pixhawk flight controllers (it’s even happened to me on a Pixhawk1) but we’ve had a few reports of users using the Kore carrier board.


We are pretty sure that we have found the solution to the parameter reset issue. The discussion is over on this thread.

@rmackay9 many thanks for the information! It hasn’t happened again since then. I also found the Wiki article about the problem.

Thanks for your engagement! It is really great how fast the development here is progressing!

today I had again a parameter reset. After a successful autotune flight and reboot everything was gone. Two questions:

I uploaded a parameter backup, unfortunately it now complains “Prearm: 3D Accel calibration needed”, is there a way around this? Everything was already calibrated before

Is there a simple way to read the autotune parameters from the log file?

The bugfix has not yet been published in ArduCopter 4.0.4

ok i found the PARM values in the logfile and could restore the autotune result