Warning #1: an issue has been found with Tower's Pause button which can cause the vehicle to fly to an old position if the vehicle has not sent a position update to Tower in some time.

Warning #2: Copter-3.3.2 fixes a bug found in Copter-3.3.1's desired climb rate initialisation which could lead to a sudden momentary drop when switching from Stabilize or Acro to AltHold, Loiter or PosHold.

Warning #3: Copter-3.3.2 fixes an issue found in Copter-3.3.1 which could lead to hard landings in RTL or AUTO if the WPNAV_SPEED_DN was set too high (i.e. >400 or 4m/s) and/or the WPNAV_ACCEL_Z was set too low (i.e. <100 or 1m/s/s).

Warning #4: a bug was found in Copter-3.3 which could cause a sudden crash if you abort a Take-off initiated from a ground station.  Video description is here.  The bug is fixed in Copter-3.3.1 so we recommend upgrading.

Note #1: AC3.3-rc8 corrected a long standing bug in the HDOP reporting.  HDOP values will appear about 40% lower than previously but this does not actually mean the GPS position is better than before.
Note #2: if upgrading from AC3.2.1 the vehicle's accelerometer calibration needs to be done again.
Note #3: set SERIAL2_PROTOCOL to "3" and reboot the board to enable FrSky telemetry like in previous versions.
Note #4: the wiki will be updated over the next few weeks to explain how to use the new features

Copter-3.3.1 is available through the mission planner.  The full list of changes vs AC3.2.1 can be see in the ReleaseNotes and below are the most recent changes since AC3.3.

Sadly this version (and all future versions) will not run on the APM2.x boards due to CPU speed, flash and RAM restrictions.

Changes from 3.3:

1) Bug fix to prevent potential crash if Follow-Me is used after an aborted takeoff

2) compiler upgraded to 4.9.3 (runs slightly faster than 4.7.2 which was used previously)

Changes from 3.3-rc11:

1) EKF recovers from pre-arm "Compass variance" failure if compasses are consistent

Changes from 3.3-rc10:

1) PreArm "Need 3D Fix" message replaced with detailed reason from EKF

Changes from 3.3-rc9
1) EKF improvements:
    a) simpler optical flow takeoff check
2) Bug Fixes/Minor enhancements:
    a) fix INS3_USE parameter eeprom location
    b) fix SToRM32 serial protocol driver to work with recent versions
    c) increase motor pwm->thrust conversion (aka MOT_THST_EXPO) to 0.65 (was 0.50)
    d) Firmware version sent to GCS in AUTOPILOT_VERSION message
3) Safety:
    a) pre-arm check of compass variance if arming in Loiter, PosHold, Guided
    b) always check GPS before arming in Loiter (previously could be disabled if ARMING_CHECK=0)
    c) sanity check locations received from GCS for follow-me, do-set-home, do-set-ROI
    d) fix optical flow failsafe (was not always triggering LAND when optical flow failed)
    e) failsafe RTL vs LAND decision based on hardcoded 5m from home check (previously used WPNAV_RADIUS parameter)

Thanks for your testing!

Views: 375199

Reply to This

Replies to This Discussion


Thanks for the report.  That really does look pretty terrible with the vehicle oscillating quickly in roll and pitch at a couple of times in the flight.  I suspect reducing the WPNAV_ACCEL to 100 will help but it's current value of 200 doesn't seem high enough to cause this problem.  I'll have a chat with Leonard about this and get back to you.

Thanks Randy for your explanation.

So is it possible that when failsafe-land kicked in, I was actually fighting with the EKF/GPS? Maybe EKF/GPS was pushing the copter forward and my RC2 was pulling the copter back?

If this is true, I think the situation maybe avoided as follow.

- in failsafe-land mode if there exists pilot input on RC1/2/4, stop listening to EKF/GPS and listen entirely to the pilot input

- in failsafe-land mode if there is no pilot input, listen to the EKF/GPS

That is giving pilot command the highest priority if EKF/GPS and pilot are both "talking" to the autopilot at the same time. With this my copter would have entirely listen to my RC2 pitch-back and wouldn't lean to the front by itself.

If it takes 12 months and 50 RCs to get a stable and reliable release, I'll gladly wait and keep flying 3.2.1.  Last thing I want is a FCS that I cannot trust or that crashes my birds due to errors or bugs.  I'm fully capable of doing my own crashes without help from an unreliable FCS.

Hi ,


The “ping-pong” between 2 GPSs is old (not a rc10 issue) .....  I don’t have the logs anymore, but from August I removed the second GPS from my Quadcopters…. The Crash is really difficult to happen, but happen in different conditions.



Leonard and I had a look and we suspect the EKF is having some problems with the altitude a climb rate estimates.  Vibrations are a little high including a small amount of clipping during the time of sever oscillations.  Of course we're not sure how the flight controller is mounted but you might want to try isolating the flight controller with the 3M foam or hobby king orange foam if you're not already.

Also we have a few suggestions for tuning changes for the alt hold controller:

  • reduce VEL_Z_P from 6.0 to 5.0 (the default)
  • reduce ACCEL_Z_P from 1.0 to 0.5
  • reduce ACCEL_Z_I from 2.0 to 1.0

Could you give these a try and see if it helps?

I found my mistake: From the wiki it is not clear if we must disable the mavlink heartbeat for using serial protocol. With the older versions it works with the enabled mavlink heartbeat. But with the newer storm versions you must disable it to get serial protocol working. Maybe the serial setup should be explained a little bit better in the wiki.

Many thanks


Great you found your issue. About the Wiki though, since it IS a Wiki you are free to sign up and make edits which frees up the devs time to actually do devvy working you know. Just saying.

Did you try doing a esc calibration after the update and before you changed you mot_spin?

A bit of a question here: has the way RSSI being reported in the mavlink been changed in 3.3? I have a strange issue when I setup up my RSSI pin 103 and range 3.3v MP shows correct rxRSSI, however minimosd shows constantly 0. I roll back to 3.2.1 and I get RSSI back, while with exactly the same settings RSSI is 0 in the minimosd while correct value in MP. Please advise. 

So is the two GPS issue solved in rc10 or is it safer to run with only one?

no idea sorry.

appreciate your reply and I truly respect all the good work of the developers and beta testers to create a high quality product.

Please allow me to raise one observation after following this thread over the past months. In my view the software got too complex in the meantime, the increasing number of copter config options and to be supported 3rd party devices and clones is compromising speed of innovation.
In my view 3DR made the right decision to split the Arucopter code for Solo, otherwise this great product would have missed the market opportunity.
So I shut up here and put my Pixhawk project on hold and patiently wait for the release.
In the meantime I enjoy my new Solo :-)
Best Stephan

Reply to Discussion


© 2020   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service