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 –


      • Randy is right as usual, but he is a brave man ;-)

        I am not and would like a calm controller...

    • I sent you reply in the other thread: too much Y vibrations.

  • Here is my S900 with AP3.3 on Pixraptor in "War of drones ;-)"

    3702242340?profile=originalPhoto by Ventzi Petrov in Rhodopi mountain (Bulgaria).

  • Hi,

    I have the inverse problem: have to lower rpm.

    I want to fly with 6S LiPo instead of 4S to get some more minutes of flight with the same setup.

    The hexa rocketed over 200 meter into the sky with the 6S LiPo :o (after 5 minutes I managed to land in LOITER but it likes a slow motion landing because of the higher revs)


    Question: Will AUTOTUNE solve this in a way or should I set to all minimum THR_MID and THR_MIN ??

    I worry another rocket start and still feel unsure to try again :/

  • Dear randy and all friend.

    i have check fly with 3.3.3 fw 1gps and my drone is work fine. but after use 2nd gps neo 8m. Problem when i take off it's good. but after some second my quad is going down and up. i'm trying to land and it's said Compasses inconsistent. so can't fly anymore, but after home, i try to connect again, and all are fine. don't know why, maybe interference somewhere ? logs is below.

    my quad :  3dr pixhawk, 3dr gps lea6, 2nd gps neo 8m. motor air gear 920kv.

    Thanks all.

    • I have been running 2 GPS on mine for months,  not a single issue. Ran them on 3.2.1 and now on 3.3.3

      You can't have both GPS be same exact model,  one if them has to be better than the other,  I run and M8N and a problem for me,  the M8N is always the primary with lowest hdop. If you have them both same then it will flip back N forth between them and get sudden position changes.. You don't even seem to have a GPS issue but  a compass issuu,  you definitely can't run two external compasses 

    • Remove the 2nd GPS. There are still issues with 3.3 and 2nd GPS modules.

      • thanks you. i will. can i backup to 3.2.1 and use 2nd gps ? or 3.3 ?

        • You need to wait for 3.4 from what the devs have been saying.

  • Been trying months off and on to get my quad tuned properly, autotune results create high and violent oscillations that my gimbal cant compete with. Tried lowering in all sorts of combinations the stab and rate pids, with little success, I either go from it feeling like a feather with the littlest bit of wind, or it having violent oscillations but more locked in.

    It is a bit over powered, but i've already adjusted the throttle hover, based on what i saw in the logs.

    Also after tuning, all motors behave weirdly, if its on a flat surface, all spin up at the same time, but if theres a slight slant eg, its leaning to the left, only motors on the left spin up, right side doesnt move, till I raise the throttle.

    I use an alien 680mm frame with 15 props,

    ztw 4oa esc's flashed with blheli( had synce issues with simonk)

    heres a link to my last flight logs.

    Dropbox - Link not found
    Dropbox is a free service that lets you bring your photos, docs, and videos anywhere and share them easily. Never email yourself a file again!
This reply was deleted.


DIY Robocars via Twitter
RT @a1k0n: Did I get rid of hand-tuned parameters? Yes. Am I still hand-tuning more parameters? Also yes. I have a few knobs to address the…
4 hours ago
DIY Robocars via Twitter
RT @a1k0n: I'm not going to spoil it, but (after charging the battery) this works way better than it has any right to. The car is now faste…
4 hours ago
DIY Robocars via Twitter
RT @a1k0n: Decided to just see what happens if I run the sim-trained neural net on the car, with some safety rails around max throttle slew…
10 hours ago
DIY Robocars via Twitter
DIY Robocars via Twitter
RT @SmallpixelCar: @a1k0n @diyrobocars I learned from this. This is my speed profile. Looks like I am too conservative on the right side of…
DIY Robocars via Twitter
RT @a1k0n: @SmallpixelCar @diyrobocars Dot color is speed; brighter is faster. Yeah, it has less room to explore in the tighter part, and t…
DIY Robocars via Twitter
RT @a1k0n: I'm gonna try to do proper offline reinforcement learning for @diyrobocars and throw away all my manual parameter tuning for the…
DIY Robocars via Twitter
RT @circuitlaunch: DIY Robocars & Brazilian BBQ - Sat 10/1. Our track combines hairpin curves with an intersection for max danger. Take tha…
DIY Robocars via Twitter
RT @SmallpixelCar: Had an great test today on @RAMS_RC_Club track. However the car starts to drift at 40mph. Some experts recommended to ch…
Sep 11
DIY Robocars via Twitter
RT @gclue_akira: 世界最速 チームtamiyaのaiカー
Sep 10
DIY Robocars via Twitter
RT @DanielChiaJH: Always a good time working on my @diyrobocars car at @circuitlaunch. Still got some work to do if I’m to beat @a1k0n howe…
Sep 10
DIY Robocars via Twitter
RT @SmallpixelCar: My new speed profile for @RAMS_RC_Club track
Sep 10
DIY Robocars via Twitter
RT @SmallpixelCar: Practiced at @RAMS_RC_Club today with my new @ARRMARC car
Aug 28
DIY Robocars via Twitter
Aug 24
DIY Robocars via Twitter
RT @gclue_akira: 柏の葉で走行させてるjetracerの中身 #instantNeRF #jetracer
Jul 4
DIY Robocars via Twitter
Cool web-based self-driving simulator. Click save when the AI does the right thing
Jul 4