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 Aleksey,

          I am not sure what you are telling me with your tuning results. If you have a problem could you also provide a tuning log.

          RC6 should be out by the weekend.

  • I'm a latecomer to beta testing v3.3.

    I've had many successful flights with v3.2 but with v3.3rc5 I often cannot get it to arm. APM Planner says it needs a "3D Fix", yet I have 8 or more satellites and hdop of 1.6 - 1.9. I've even cranked up the HDOP threshold to 400 (i.e., 4.00)

    First thing this morning I did get it to arm (after quite some time) so I successfully did the autotune process. After landing I changed the battery and tried to do another flight but couldn't get it to arm. I've had "prearm chk mask" = 1 (everything) so I tried to exclude only the GPS check but APM Planner doesn't seem to let me upload a number greater than "127" (and unsigned char??).

    Could the "Need 3D Fix" message be generated by the failure of something else beside the GPS? I'm using a HKPilot32 (Pixhawk clone) with Ublox M8N gps on a F450 frame. 

    Can anyone shed some light on this?

    • Depending on your fpv transmitter frequency, 2.4 being the worst, it can generate a lot of noise and make aquiring sats difficult.

      I like 2.4 for video and ended up using channel 2505, trying different antennas and maximizing separation until the GPS stopped complaining.
      • My fpv is on 5.8 but I've eliminated that so far. However my RC is on 2.4 so that could be an issue. I've violated one of the rules of troubleshooting by changing two things at once (moving FrSky antenna and unplugging the 915Mhz telemetry radio) but I've been able to arm now. It remains to be seen how repeatable that will be.

        In any event you guys led me in the gps interference direction and that might well be the problem. If this is repeatable then I'll re-connect the 915 telemetry & see what happens. Would be nice to know if v3.3 does more checking of gps position information quality than v3.2 was doing which would explain why this is just happening now.

        • It appears that v3.3 with its EKF algorithm implementation is handling gps "glitches" differently, and probably much more rigourously (spelling???).

          In any event I have found that the gps interference was most likely caused by the 915Mhz telemetry radio. I put the RC antenna back to original position & it didn't appear to make a noticeable difference. I'll move the telemetry radio to the opposite side to see if it was a proximity problem (gps is on a pedestal on top, telemetry radio in mid section with antenna hanging down) or if it's conducted interference though the wiring.

          Although this problem caused a minor inconvenience, I'm pleased to see that the latest firmware is more thorough in checking the integrity of all systems before launch.

          Thanks Craig, Paul, & Wes for your help, and a big Thank You to the Dev Team for all the hard work! I'm liking V3.3.

          • That's odd for sure since my 915Mhz telemetry radios are about the only thing that do NOT produce any noticeable noise lol.

            • I've seen an instance of the 3DR 900Mhz mavlink radio making a Pixhawk throw up lots of IMU errors, but the antenna was both horizontal same as the Pixhawk orientation, and fitted barely 20mm from the side of the case. That was nearly as bad for RF coupling as you could get and easily fixed by more suitable antenna placement. 

              Also had my FrSky D8R RX antenna drop my GPS sensitivity down enough to make HDOP sit above 3 all the time, again the remedy (once I knew it was the reason) was move the FrSky RX antennas away from the GPS receiver. 

              On my copters I now use a GPS riser mount at the back of the copter, and fit the FPV and Mavlink antennas out at the front. Even better would be out front and hanging below the chassis. I don't have GPS issues anymore.

              Antenna separation is your friend when it comes to RF coupling and interference...

              • +1 for antennas separation. :-)

                When "less weak than usual" Tx are used, care of antennas and positioning is quite important. 

                Mavlink 900 MHz by rfdesign 900 MHz modem gives up to 1 Watt output.

                (software power setting is great!)

                Video down link: 2.5W 1.3GHz Video Tx

                Main batteries telemetry (2.4GHz): Cell by cell telemetry values

                I believe in following each individual cell instead of total voltage.  (But that is just me LOL)

                And FRSky telemetry for electronics 5 Volts


                Radio Modem Bundles - RFDesign
    • Hi,

      I by no means intend to respond instead of develpers who know best but I had same situation going on with telemetry screen showing 10-12 stas and low hdop but drone would not arm saying same 'need 3d fix'.

      this problem combined with very slow progress rate from 5-6 sats to 10 sats was all related to a high level of  EMI interference from the boscam transmitter 20cm away and FC BECs modules - so it took to put a solid copper plate under GPS unit for isolation and I look to do proper shielding now for GPS unit.

      After this shielding it locks into 12-14 sats in less than a minute - M8N unit - and never plays this #D lock error message again if it shows me proper HDOP in the telemetry.

      • @Paul: Thanks for your response.

        I don't power my fpv transmitter until I'm ready to go (otherwise it seems to get too hot) but one antenna from my FrSky D8R-XP is within about 10cm from the gps. I wonder if it's the telemetry transmitter that could be causing the problem?

        Strange thing is that this problem only started when I went to v3.3. Perhaps this version is checking for gps velocity problems that get reported as lacking a 3D fix? Anyway, I'll try to eliminate sources of interference to see if that will help.

This reply was deleted.


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