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 Dave,

                    Thanks for that, no problems! 

                  • leonardthall:

                    yes, you convinced me already. Just didn't have the other logs here (just the one I uploaded) and didn't have time to look after it just yet.

                    I was so sure that this was the right log, that I just wanted to show you, why I felt so sure. (errors and map).

                    You are of course way more experienced and into the whole topic so that it was clear to you from the first second that it isn't the right log.

                    I will look for the right log as soon as possible!

                    Sorry for the inconvenience caused.

                    Thanks for taking your time.

                    Richard Kennedy:

                    Yeah, I was really really lucky. It was the perfect place to crash (freshly loosened slightly wet field). I still wonder how the landing legs could survive :D

                    The motor mounts are twisted because of the crash. They were solid and straight before. (They are just clamped with a screw, there is no bolt going through the carbon fiber)

                  • Developer


                    Your copter looks like it rotates more than 25 times during that crash. The log you show takes 45 seconds from full throttle to the time it gets to the ground and doesn't spin. Your video takes 13 seconds to crash and spins 25 ish times.

                    THIS IS NOT THE CORRECT LOG!!!

                    I can see you don't know how to read logs and are here because you need help understanding what happened. The dev that designed the controllers in arducopter is telling you that the log you provided is not the same log in your video.

                    Please take the time to listen to the people that are trying to help you. You are currently wasting the time of the helpful people on this forum that are trying to help you.

                  • Yea I’d say your quad looks damn good for a 60M crash! This is probably unrelated but one thing I had happen once was somehow two of my arms got twisted and as luck had it it was two opposing arms hence the motors spin the same direction. What happened then was it could not compensate for the yaw effect that caused so even with full right yaw stick it continued to yaw left. However it didn’t cause a crash and of course it was evident the moment I took off. In my case the aluminum arms get bent slightly in travel. I was amazed at how little it took to create that much of an issue. Just looking at yours I wonder if two of the motor mounts twisted on those round arms? But of course the log would show it trying to compensate with full yaw opposite it's actual yawing. 

                  • Hello Richard,

                    all my props are fine (just one slight cut-in at one prop which definitely came from the crash) even after the 60m drop. I was really lucky.

                    I use Aeronaut CamCarbon light 13x6 props.

                    Here is a pic I made after the crash.


                  • I had two crashes when a prop tip broke off it looked sort of like that. That was the last time I used cheap props. 

                • Usually with one motor out of sync the copter will drop on that side and the FC will try to correct attitude by increasing RC_Out of that motor. There is nothing like that in your log.

                • Developer

                  Hi Dave,

                  sync issues will be clearly seen in your RCOUT log if you had the correct log. You will see one of your outputs pegged to maximum while the others struggle to keep control. You will also see the yaw log go nuts as it spins.

            • Saw this over at RCG


              If you're running BLHeli and 14.2 then you need to upgrade to 14.3

              "I've just read that 14.3 is out due to 14.2 having motor glitch issues near high throttle. Check it out."

              RC Groups - View Single Post - Little Bee and MRM Zeus 20AMP ESC's
              RC Groups - the most active Radio Control model community: electric and fuel rc airplanes,rc helis,rc boats and rc cars. Features discussion forums,…
            • you can try giving your ESC+motor extreme change of throttle input. if there is out-of-sync issue waiting to happen, these test should kick them right out!

              make sure you use your fight controller hardware to drive your ESC/motor speed. for making sure the signals in your test-bench is exactly the signals during actual flying.

              I had a crash with my big copter also due to out-of-sync!! the ESC was DYS simonK 30A! since then I bench-test ESC for checking any out-of-sync hazard.

              you may check out my video on out-of-sync test: hobbywing Pentium pro 30A is also unhappy with my copter! while hobbywing x-rotor 40A works perfectly and it is "certified" to be in mid-air with me ;)
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