Copter-4.1.4-rc1 available for beta testing!

Copter-4.1.4-rc1 has been released for beta testing and can be downloaded using the beta links in MP or QGC (or you can download directly from

The changes vs 4.1.3 are in the ReleaseNotes and also copied below

  1. Benewake CAN Lidar support
  2. CAN GPS default lag dropped to 0.1 seconds (was 0.22 seconds)
  3. Bug fixes
    a) Compass custom orientation is never overwritten during calibration
    b) EKF logging gaps fixed (some messages were occasionally being skipped)
    c) Guided mode cornering improvements
    d) IMU logging fix for IREG message (records IMU register changes)
    e) LOITER_TO_ALT mission command’s climb rate fixed (could climb or descend too quickly)
    f) Position controller init fix to avoid twitch on vehicles with high vibrations
    g) Position controller init fix to better handle high speed entry to flight mode
    h) Position controller prioritises reducing cross track error
    i) Position controller relax fix
    j) SBUS RC frame gap increased to better handle some new receivers
    k) SERVOx_FUNCTION protection to avoid memory overwrite if set too high
    l) SD card init triggering watchdog fixed
    m) Spline path max lateral acceleration reduced (vehicle stays on path better but may be slower)
    n) Takeoff bug fix if taking off below home or frame specified as MSL

There are a few navigation and position controller changes so although most users may not notice a difference all feedback is greatly appreciated!

Assuming all goes well we will release this as the stable version in about a week and then move onto Copter-4.2.0 beta testing.


First Testflight with Copter-4.1.4-rc1

Hexsoon TD 650
CubeOrange Copter-4.1.4-rc1
Lightware LW

All running perfect…
Stable, AltHold and Loiter

Flight Indoor
RC9_OPTION = 90 (EKF Pos Source) low is GPS, middle is OpticalFlow, high is unused
EK3_SRC1_POSZ = 1 (Baro)
EK3_SRC1_YAW = 1 (Compass)
EK3_SRC2_POSXY = 0 (None)
EK3_SRC2_VELXY = 5 (Optical Flow)
EK3_SRC2_POSZ = 1 (Baro)
EK3_SRC2_VELZ = 0 (None)
EK3_SRC2_YAW = 1 (Compass)
EK3_SRC_OPTIONS = 0 (Disable FuseAllVelocities)

Setup Rangefinder for testing to RNGFND1_MAX_CM = 700
and there is a little problem or its for safety ... i dont now

in loiter mode with EK3_SRC2 the maximal altitude is 400 cm (60% of Rangefinder Max) no more climbing …
in AltHold no limit

Logfile Nextcloud

1 Like

thanks for the awesome information.


Txs very much for the testing.

The vehicle’s maximum altitude is limited when using optical flow is used. I think it is 60% or 70% of the rangefinder’s maximum range.

Hi Guys,

I am testing EK3_SRC1_POSZ = 3. I need very stable relative flight, but I was returned very lost altitude in same flights using Baro to POSZ, after change to GPS option, my flights are perfectly fixed altitude, I need this because my agricultural drones flight above 2m over trees, and Barometers get 1 until 5m of errors, I tried TCAL but no success.

How problem can I see if lost good signal GPS during flight using GPS source to alt ?

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