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 –


        • When you say "on the ground" is this on concrete? I've seen rebar play havoc with the compass' and it goes away when I move it over to the grass..

          • Nope, on grass. Just weird because I've never had an issue like this before.

  • Hello, I just want to report that today I  finally was able to fly, the weather wasn't allowing.

    3.3.2 flew awesome! No issues. Congrats to this great team!

  • Relationships between PID settings - Vibration - INS_ACCEL_FILTER settings?

    Can anyone explain these relationships? I found on my FW-450 with Pixhawk (3.3.2 fw) / RCTimer MT2610 920kv, BLHeli 30A, 1045 prop at default I_ACC_FLtr = 20 and using 3DR foam for FC mounting I have vibration (IMU_AccelZ plot) between -11 to -9 (+/-1g) should be good (at least it is 5 times smaller than recommended) but in AltHold it is still jumps up and down a bit.

    On newly assembled nighthawk clone (320 base with APM mini, M8N GPS, EMax MT2208 II, BLHeli-20A) FC set on harder foam and this FC is small and light so not much vibration dampening. At filter INS_MPU6K_FILTER set for 20 vibration between -15 and -5 (AccelZ) with filter set to 15 - vib. -12 to -7 but the flight behavior (oscillations) as if I am tuning PID, very similar to a bit higher values of rate P.

    Is it possible to set lower values of INS filter (to get lower vibration) and compensate oscillations with PID tuning?

    APM is notorius for vibration sensitivity, I could not get it to PosHold almost at all, Pixhawk is a bit better, but only with very soft foam pad - may be it could be alleviated by FILTER - PID conbination? 

    Any Ideas? Explanations?

  • I'm have a bit of an issue on my 960 hex with inconsistent compasses.  It shows up on pre-arm quite often and requires several compass calibrations to settle in regardless of where it is or if it armed previously at that location.  Compass offsets are always different every time I calibrate and below 400.  The setup is the same as my 550 quad and my 690 hex that have remained set unless I change hardware.  The only difference is that I have doubled the distance of external compass to airframe.  This thing has 3 to 4 times the power draw as the little guys so I expected it to be more sensitive but I'm getting tired of doing the calibration dance with such a large, heavy partner.  It always flies perfectly in loiter or position hold once armed.  To be clear, when looking at compass offsets on the parameter list, is compass 2 the external and "compass" the internal?  And would COMPASS_LEARN be something to try?

    Pixhawk, Zubax GNSS module

    Thanks  RB

    • Look at the compass?_dev_id. My pixhawk have the internal ID = 131594. My external ID = 73225 , it is a genuine 3dr ublox gps. In my conf , the compass_dev_id is the external  and compass 2 is the internal. You shoud set the compass_primary to wherever your external compass is at. Try that and see if helps.

      I have never used compass_learn...

      • Thanks for the advice, I do have the external as primary. I ended up moving the pixhawk and the zubax another 10mm off the deck and it seems to have helped a bit. I did four consecutive calibrations and they were not too far off from each other and passed pre arm checks each time.

        Cheers, RB
  • Hey guys, I have a Y6 running 3.3.2 and today I decided to test its max carrying capacity, by adding about 3kg payload bringing total weight to about 8kg, it was flying fine with 6-7kg I designed it to carry, however at 8kg It constantly wanted to rotate CCW. I've checked RCOut logs and it looks like motors 2,4,6 were at 1700, while motors 1,3,5 were at 1400. Does it suggest that I should be runni g bigger props at motors 2,4,6? 

    • Developer

      Hi Artem,

      This is actually a really interesting question. You need to increase the drag for a given RPM. Increasing the diameter of 2, 4, and 6 may do this. But with the interaction of the upper and lower props it is very hard to say.

      So a long story short, I don't know but I am really interested to hear what happens when you try different things. You can increase the pitch on the lower props, you can try increased diameter on upper or lower props, or you can increase the CV on the lower motors.

      Let us know how you go!!!

      • Thanks leonardt, I've ordered a few 1655 cf props from china, will test with both - upper and lower. Btw, did you mean KV (CV)? 

        The scarse info on coax setups I was able to find suggests that lower props should have larger diameter. Inceasing the pitch is usually not enough. 

This reply was deleted.