Copter-3.3 beta testing

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!

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


          • Hi Leonard,

            Ok I'll give it a shot, enter the values for MOT_THST, leave the Autotune results like they are, and reduce RC_Feel, with RC5, and fly today..

            Thanks for your feedback...

    • When you say a swim you mean the copter got completely wet aka crashed in the water? I thought that ruined the baro sensor... maybe not? 

      • Hi Richard,

        It was completely submerged, but after taking all components apart, to dry with a hot air dryer, it seems that all electronics survived. just lost one Motor which was smoking when I took it out, including the corresponding ESC.
        • Your fast actions probably saved it. I wish I knew of a type of fuse that would open if it detects water. It would be nice if the lipo was instantly disconnected if the copter crashed into the drink. It would probably save the esc's too. I think I'll research it a bit. Gotta be something. 

          • Yep, if there is anything available to control the gate of an BTS555 which I am using as master switch for all Power on the HEX that would be great.

            Currently I am pulling the gate down to ground with a low voltage switch.., and if that can be replaced with something that "smells" water that would save electronics.

            On the other end you'll still need to take everything apart to dry it out, so it's better not to drop in water at all..

            That's rather difficult in the Netherlands, too much water all around... ;-)
      • I didn't understand that statement as well. What is that "resent swim" supposed to mean?

        • Hi Alex,

          See page 11
          • Checked it just now. I remembered that incident as soon as I started reading it.

            So it is still flying!..:)

    • I had exactly this issue with 3.2-rc14 the drone was over responsive after the Autotune.

      I started this threat in December 2014:

      after doing the AutoTune the drone becomes too responsive (over sen...

      Mabe Autotune is not recommended for all frame sizes and does work quite well for some of them!?

  • For me I also think that autotune is giving not the best results for my T960: The difference in reaction between roll and pitch seems to be significant. At the moment I think I must do every axis with another aggressivness.

    Autotune_AGGR 0,1: Overall Motor Vibrations and oscilating rcout on M5 and M6

    Autotune_AGGR 0,07: No vibrations, Roll to sensitive, Pitch to weak, Yaw terrible (Large overshots)

    Next I will try Roll on 0,06 Pitch on 0,08 and Yaw on 0,09.

    But I will wait till the next RC or may the final.

    Maybe this will give the same performance on each axis.

    Sorry the logs are to big, and on my laptop. I will try to sent them later via link.

    Cheers Gregor

This reply was deleted.


DIY Robocars via Twitter
DIY Robocars via Twitter
May 14
DIY Robocars via Twitter
May 13
DIY Robocars via Twitter
RT @f1tenth: Say hi to our newest #F1TENTH creation for @ieee_ras_icra next week in Philly. It’s going to be huge! 😎 🔥 @AutowareFdn @PennEn…
May 13
DIY Robocars via Twitter
May 11
DIY Robocars via Twitter
May 8
DIY Robocars via Twitter
RT @SmallpixelCar: Noticed my car zigzagged in last run. It turned out to be the grass stuck in the wheel and made the odometry less accura…
May 8
DIY Robocars via Twitter
RT @SmallpixelCar: Test my car. RTK GPS worked great. Thanks @emlid for their support.
May 8
DIY Drones via Twitter
RT @chr1sa: @kane That's @diydrones circa 2009. Still have a box of those Canon cameras that we used to strap into planes, just like this.…
May 3
DIY Robocars via Twitter
RT @chr1sa: Our next @diyrobocars race is going to be outside at a real RC racetrack in Fremont on May 28. Fully autonomous racing, head-to…
Apr 30
DIY Robocars via Twitter
RT @f1tenth: Our Spring 2022 F1TENTH course @PennEngineers is coming to an end with a head-to-head race as a big finale. So proud of our st…
Apr 26
DIY Robocars via Twitter
RT @DanielChiaJH: I wrote a thing! Throughout the development of my @diyrobocars car I've been using @foxglovedev Studio to visualize and d…
Apr 23
DIY Robocars via Twitter
RT @SmallpixelCar: My new car for high speed. Low body, everything ( @NVIDIAEmbedded Jetson Xavier NX, @emlid RTK GPS, IMC) under the deck…
Apr 23
DIY Robocars via Twitter
Apr 21
DIY Robocars via Twitter
RT @f1tenth: F1TENTH Race training setup @PennEngineers for our upcoming ICRA2022 @ieee_ras_icra competition. @OpenRoboticsOrg @IndyAChalle…
Apr 21
DIY Robocars via Twitter
RT @fatcatFABLAB: Proud to be hosting a restarted DIY Robocars NYC Meetup April 26. Come by if you want to talk about and race self-driving…
Apr 17