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!

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  • Developer

    Hi Trent,

    An overheated ESC would definitely fit the bill!!! That would explain why you didn't loose all power. Being your first flight going that long and with extra weight all makes sense.

    As you said, that flight doesn't show any signs of the same problem.

    Good luck and let us know if you learn more!!

  • This is probably not the right place to post this, my apologies, but as there are a number of devs on this thread, perhaps I can get pointed in the right direction.

    My hexa is flying nicely with 3.3 and Lidar Lite, so I thought it would be a good time to try out my PX4Flow. Used QGC to update the firmware and set the focus, then plugged it in. First problem I have run into is that it has to be powered by USB before the main battery. Apparently, it is a known problem and it says on the wiki to notify the devs, but it doesn't say how/who/where. Is there any workaround for this? One thing I did notice, that may help to narrow down where the problem is, is that if I power it with the battery first, the altimeter on the MP GCS shows the altitude going up very rapidly (goes up to thousands of feet), but when I check the baro in the log, it shows the altitude correctly.

    Is the OF functionality going to be enhanced in 3.4 and is there a spec for it anywhere? Thanks!

    • I with you, lidar and PX4flow on the bench...
      Info is still sketchy.
      • Tested my height following with lidar today. Passing close over my car ( noooooooo ) and even over me and it works beautifully. My only comment is that we need some indication of what is in charge of height,  ( as opposed to altitude ). An indicator on the GCS that the vehicle is height controlled ( sonar/Lidar ) as opposed to altitude ( Baro/GPS )  would be nice. Perhaps even an added channel control to follow sonar/lidar - terrain following?

        copter 3.4 anyone?

  • The escs are 30A with blheli, batt cutoff disabled, flew them on a big apm hexa for 2 years with no issues, this build is a small quad 1000kv motors with 9x4.7 carbons, same escs Tgy AE30. I just finished the repairs, I have found no problems with any of the soldering/wiring.Uploaded 3.2.1 and will put it trough serious trials, although I've already done that for a few days prior to the crash with 3.3. Thank you all for inputs, I'll keep you updated.

  • Developer


    Hi Trent,

    It is very clear from your log that you lost motor/esc 4. I can see from your log that this happened very quickly but it also didn't stop fully so you may have burnt out some windings on your motor. Based on the fact you didn't lose the thrust completely I suspect you don't have a problem with your wiring. You may have lost some of your fets in the esc. You may also have a prop loose or broken (but I suspect you would have seen that). Problem is you should have seen all this in your next flight.

    The only other thing that may have caused this is noise on your signal line connecting your pixhawk to the esc. I have had this problem on my high powered quad and had to make sure I didn't run the ESC servo wire next to the power wires.

    The only good news is this isn't the autopilot, it is something between the output of the pixhawk to the esc, the battery, to the prop.

    This one is a head scratcher. Sorry I can't help more!! 

  • Developer

    I also tried to download the log and could not becomes of a permission problem.

  • Developer

    Hi Trent,

    Sorry about your crash. I can't download you log. Can you give me permission?

  • This is my first post on diydrones, so hello everybody! Unfortunately I have to start with a crash. To cut the story short because I think I may have encounter a serious issue with AC3.3. Uploaded the firmware about a week ago, mainly because of the LG an Storm32 support. Flew without any issue, only once I think when I RTL in the descending phase over home is started wobbling kind of serious, I had to put it in stab and descend manually and it settled. All other autolandings were fine. Now the main issue, took off yesterday for the second time (on the side note, I was conducting a search over the sugar cane filed in search for a lost arduplane, flew LOS at low alt over the field and got caught in a downdraft, plus it was getting pretty dark) after a steady 6-7s climb (see log) the copter destabilized and crashed pretty badly right on the schnoz, (good thing it was wearing the newly handcrafted, perfectly balanced ST32 gimbal as a helmet). Looking at the logs I was puzzled to see that ch3 out went completely idle right before the crash for no apparent reason, the mag acc an gyro were stable, and the time frame tells me that the ch3 went dead prior to any change in the imu.I hope you guys can clarify this, maybe I am missing something. Just to add, my builds are very sane and thoroughly checked to the last detail, I'm a bit of a freak in this field so a mechanical problem is most likely out of question. I'll upload the video shortly, my internet conn is knd of sluggish.


    Ed AC3.3.param

This reply was deleted.


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