Copter-3.4-rc5 available for beta testing

Copter-3.4-rc5 is available for beta testing. Release Notes are copied below. As per usual, the firmware can be downloaded from the Mission Planner’s Install Screen’s “beta firmwares” link. It can also be downloaded directly from

Changes from 3.4.0-rc4:

  1. Sprayer enabled by default (
  2. Bug fixes, minor improvements:
    a) EKF fix for yaw angle reset fix when switching between cores (AC3.4 runs multiple EKFs simultaneously)
    b) EKF fixes when fusing range finder into height estimate
    c) pixracer clone board IMU hardware issue work around
    d) dataflash time-going-backwards fix
    e) fix rate PID conversion (AC3.3->AC3.4) for single, coax and tricopters

Thanks again to our beta testers! We’re almost there.


Thank you!

WIll test this weekend. Great!

…and thanks Tabascoz for all your help on the forums.

A post was merged into an existing topic: Copter 3.4-rc5 test and logs

Hi Randy,
Can you please explain this a bit more in detail? I had some weird behavior with a sonar, on rc 4.

Just reporting.

I flew today morning and it was really awesome! No errors at all. No yaw issues, nothing.

The flight was 15m long to film a construction site to build a report. Mainly loiter mode. Althold ( and rangefinder ) looks perfect now. Not even a single hiccup.

Congratulations to all the devs and the community!

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My tests of rc1 to rc4 with logs and Autotune

We’ll see what rc5 brings…we are really close…my Rate Yaw P again look very high and i am not sure is it from Autotune or (again) from PID conversions… "e) fix rate PID conversion (AC3.3->AC3.4) for single, coax and tricopters"
please check my post
no answer at all at my post…after all this tuning i think there is a lot of useful data in my logs but no one cares…thank you

Hi, I can confirm this. Board boots up, reports no error so far. Haven’t fly it yet, will take some time to assemble the copter around it…
Huge thank you!

Hi tabascoz, when you change the version of firmware you remake the calibration ?

2 posts were split to a new topic: Copter 3.4-rc5 test and logs

No, only once in rc2

Now i have 3.3.3, do you think that is necessary to recalibrate all ?

Flew rc5 today on a stock Iris+ & 3DR-Y6. Everything was great. Takeoff and landings in Stabilize and PosHold. Brake, RTL & Estop all working as expected.

Tested Tower Beta:

  • arm and takeoff from App
  • Dronie
  • multiple follow-me modes (no altitude issues)
  • manual flight path capture and replay as auto mission

Tested QGroundControl on Andriod connected via 3DR radio:

  • arm & takeoff from App
  • guided “fly to” points on tablet

I really like the pre-arm messaging and layout now in QGC along with the configuration section, but that’s probably a post for a different section.

I’m not sure if it is mandatory , but it is not a bad idea. I usually take advantage of upgrading major releases to recalibrate everything.

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A post was merged into an existing topic: Copter 3.4-rc5 test and logs

Fast IMU logging does not work anymore in 3.4. I found it to be very useful, especially when dealing with vibration in Gas/Nitro heli. Fast IMU logging enables us to do a frequency analysis of the IMU to figure out if the excess vibration is due to main rotor or something else. On inspection of the code I see that the routine “Copter::full_rate_logging_loop” has been removed. I was wondering why it is so. Can we please bring this back? Is there a reason why this was removed?

Not sure why it was removed, but here’s the commit where it was removed:

It was part of a bigger change to support having EKF2 do logging for proper replay. You can enable fast IMU logging by enabling LOG_REPLAY (and with EK2_LOG_MASK you can control which IMU is logged).

Hi Randy,

Spektrum Satellite support appears broken for PixRacer. I have tried 2 PixRacers and 3 Satellites. When pre-bound, I see serial signals from the receiver with a logic analyzer but no channels are detected in Mission Planner. Binding does not appear to work either. I monitor the VCC and the signal lines. There is no sign of the needed switch off on VCC and nothing ever happens on the signal line either. Same results on Plane.


Hi @pkocmoud,
Im using a spektrum satellite rx, works well, except the binding. For that i use an arduino.
But… it does not work with my clone pixracer.
I dont know the reason. :frowning:
Br, m.