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 –


        • Developer

          Hi Eduard,

          I can confirm what Randy said. This is definatly failure of the back right motor or ESC (#4). It may have been a low battery cut out but I think it is more likely an ESC or motor failure. One one of my personal quads I had a broken solder joint that caused intermittent crashes but on the ground everything worked. I would try giving a very solid pull on each of your solder joints on that motor/esc. The thing that tends to show up damaged windings on a motor is full throttle while the copter is held down or mismatched motor outputs in flight. There doesn't appear to be any sign of the problem leading up to the crash so I suspect that you will find this problem is something that is a good/bad situation with nothing inbetween.

          So first port of call is solder joints and low voltage cut off.

          Sorry to hear about your crash!!

        • What motors/ESCs? Could be loss of sync with the ESC if its a larger motor.

        • I'm certain Randy is right - 3 and 4 move in opposite directions at the same time and 4 is then dead. No way the FC can keep it level with only 3 motors...

  • Speaking of mini quads.

    Anyone who's flying with mini-pixhawks or mini-apms.

    Do you guys use any vibration damping, or do you just bolt it to the frame?

    • You DEFINITELY need SOME dampening regardless of what frame you use. I "used" to use a dampening plate that I made out of the top camera mount on my 250 frames but now I use This with double sided carpet tape and it works VERY well. Much better than I expected to be honest.

      • The orange foam is too thick for my QAV250. I use the neoprene foam that comes with the kit and that seems to work pretty well - on the mini quads the vibration frequenceis are much higher and seem to affect things less, so I don't think you need as much dampening as on the bigger quads.

        • Without any dampening on my 250's [I've built at least 1/2 a dozen now with 4 of them using APM Mini's] if I didn't use any [as in planting the APM down on the frame] I would get horrible ALT-Hold and Loiter modes not to mention such bad oscillations that it they literally flip on take off. One could say that it is less "important" on small frames more so because of the way they are flown [as in acro mainly] but my findings have been pretty consistent in the need of "some" dampening even on small frames. I'm betting when I swap out the APM Mini I have on my newest build with a Pixhawk Lite that it will also show the need for "some" dampening now that the EKF and Vibs graphs are available in flight. Since I am waiting on my Tarot T960 frame to come in and a rebuild of a buds 450 class quad I may take the time to swap out the APM for the Lite [god oh god the wires on both SO SUCK] to see. I guess I can mount direct to frame and test and also mount via the foam to test [I have both the white foam and orange foam] 

          Man so many projects so little time sigh. Good thing I love it lol!

  • Randy / Devs

    Can you look at my post about having a problem with SR params not staying to what I set them to work with my Taranis Lua script please?? I don't know if this is an issue with 3.3 or not. Please see my last two posts on this page... Thanks!

    • Hi,  this has likely nothing to do with 3.3 and is better discussed in the telemetry threads or with the vendor you bought it from. 

This reply was deleted.