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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        • I think this would be bad for landing in windy scenarios when PosHold/Loiter is most useful. There would be the danger that the craft would suddenly get blown sideways when the GPS was ignored.

          I wonder whether low-tech is best here. I have advocated ignoring yaw commands when throttle is at minimum in these modes so that you don't end up doing the disarm dance while the copter still thinks its flying. Why not instead of everyone switching to stab when they are on the ground have some "I've landed dance" so that the FC knows to basically shut down. e.g. if you are ignoring yaw at min throttle take full right yaw as "copter on the ground".

          • Yes I second

            • Aargh I absolutely hate this forum software. Seriously, was it designed in the 1980s? It randomly truncates replies to three words - usually the longer you spend composing the more likely it is to truncate. And why do we have a single thread with thousands of replies in a disorganised mess for such a wide topic? Why not have a separate area/forum for testing where we can have sensible threaded discussions about a single issue, like landing, or gps, or ekf, or autotune, etc etc that people can actually find, report, discuss, contribute to and come up with solutions for issues rather than each issue being lost and forgotten in the hundreds of pages of replies.

              Anyway, I had composed an eloquent soliloquy on landing issues which I won't bore myself with again, but it boils down to:
              - Cautious landing detector good, false positives and falling out of the sky bad.
              - Landing detector not always great at detecting landing in good time, causing tipovers and mangled blades.
              - An option to 'assist' or 'tell' the landing detector that the craft has actually landed would be a great addition, either using some wierd and wonderful three finger salute or by a channel switch.
              - I use a popular tarot 650sport frame which by the time you add motors and batteries is top heavy and inherently unstable in landing, prone to tipping over (as are a lot of multicopters). Extending the landing feet/rods helps considerably, I actually use pool noodles/pipe insulators to wrap around the landing rods as I land on water sometimes. With the large landing feet and hence more stable craft I've never had a tipover and the landing detector seems to work much more reliably.
              - Landing in an assisted mode (landing/althold/loiter) is safer for the vast majority of flyers, landing in stabilize should be a last resort/experts only. But landing in stabilize is the most reliable/safest from the moment it's actually touched down.

              • Fnoop, I fully agree with you on the software of this forum, there is a huge amount of very valuable information and help in some of the threads, but there is almost no way to find that information unless as you said you to scroll through hundreds of pages...

                • Agree about the software, if it only had thread tools, such as search within thread...

                  I also have the Tarot 650 sport and I never let the FC finish the land or RTL, I always switch to stabilize and land it by myself as it sometimes want's to tip over and I do fly mostly on difficult terrain (slope, near hills, forest and power lines near my LZ).

                  RC10 is much better then previous versions and far more stable on landings, but the landing detector still needs some improvements.

    • re- In a GPS controlled mode when the throttle is at minimum do not listen to GPS messages. Basically switch to AltHld mode when throttle is at minimum.

      Wow... unless I'm missing something that seems like a fantastic idea and problem solver.

  • 3.3 RC10

    Really don't know what else the PixHawk wants to arm....

    Screenshot from APM Planner via telemetry radio but the same thing happens if also connected via telemetry radio to Mission Planner. Both APM and MP latest beta version as of today.

    Issue is that even with lots of satellites and 4 as GPS lock and small (<1.4) Hdop the pre-arm checks complain about 3DGPS Fix.


    perhaps some candy ? :)

    • What kind of gps? 

    • I ´ve got some weird indication with -rc10 and Droidplanner (1.2.0 first version)as well, it says NoGPS although HDOP and SAT count are great (M8N, no noise issues). Loiter works nice, as well as PosHold and the logs don´t reveal any problem. Rather a cosmetic issue. If your bird flies great, just de-activate those Pre arm Checks :-)

      • Ive been running dual gps since rc8 release. on the MP hud i can see gps and gps2 sats they both have 10+ sats but if i unplug one gps the hud will say no gps with hdop of 100. gps2 still has 10 sats and hdop well below 2.0. i can take off in poshold and the flight mode works good even thoe MP says no gps.This is a strange bug.

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Aug 25