Copter-4.1.1 released!

Copter-4.1.1 has been released as the official version and can be downloaded from the ground stationss (e.g. MP, QGC) or directly from

The changes vs 4.1.0 can be seen in the ReleaseNotes and copied below.

  1. EK3_PRIMARY allows selection of which EKF core/IMU to use on startup
  2. ESC telemetry sent during compassmot
  3. TradHeli landing detector improvement
  4. Bug Fixes
    a) Auto/Guided mode fix to EXTENDED_SYS_STATE message’s “landed state” field after takeoff
    b) MAVFTP init fix (could cause slow parameter download)
    c) Scripting fix when logging strings
    d) Serial flow control fix (affected at least Lightware LW20 serial lidar)
    e) QiotekZealotF427 IMU (ICM42605) orientation fixed

Also for those who compile their own firmware, github made a change affecting submodules (blog post here) so the Copter-4.1 branch includes the new script that may help you if you have troubles.

Special thanks to the beta testers who uncovered some of the issues above and also helped us test this version before release, thanks!


As all ways excellent work by every one and thank you

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Thanks for getting the EXTENDED_SYS_STATE fix into this release. :smiley:

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I can confirm that “waiting for MAVFTP” issue in MissionPlanner which caused a long delay during loading params is gone! Now it connects quickly with my cube black FC. Congratulations to the developers!


Can 4.1.0 update to 4.1.1 with no modifications required? Apart the mag recalibration i guess?

It should be a straight upgrade and there should not be any recal needed


I will update to see if i can get faster param download :slight_smile:



Can I update directly from version 4.0.7 to 4.1.1. or must every intermediate version update first?

If I can update directly, then my second question would be if I need to change anything in my previous settings. I use ardupilot only in traditional helicopters.

I have already read through the release notes and I don’t think I need to change anything for me. However, I am not an expert and may have overlooked something. Would be bad if I update and then my precious scale helicopter crashes.

I would be very grateful for your support. If you want me to post my questions in the TradHeli section, tell me.

Thank you and BR


Hi @heri,

You can just upgrade directly. In general any required parameters changes are also done automatically but there weren’t many modified between 4.0.x and 4.1.1 in any case. If there are params or configuration that need doing normally you’ll see a pre-arm check warning (another good reason to leave ARMING_CHECK=1)

@bnsgeyer is really the expert on TradHeli so I’ll let him reply re whether there’s anything else to be careful of when moving between 4.0.x and 4.1.

param download seemed to be much faster for me

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Thank you for your help.




Have 4.1.1 on both my OrangeCube copters - both working great - Thank you DEV Team!


Wow! I haven’t upgraded for a long time. Looks like I’m still using APM:Copter V3.4.6 (e707341b). What all would I need to calibrate upgrading to 4.1.1?

I have a Holybro PX4 2.4.6 PixHawk.

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In general the parameters will be upgraded automatically but 3.4 is so old that I can’t completely promise that… still, I suspect you’ll find that it will go surprisingly smoothly.

I’m pretty sure you’ll need to re-calibrate the compass and an accelerometer calibration may also be required but an arming check should trigger to warn you what is required in any case as long as ARMING_CHECK = 1.

Thanks for the info. It’s been a crazy couple years. My flying and keeping up with the developments have fell by the wayside. Hopefully I will have more time to keep up on these things. One of my favorite things to do. :grinning:

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