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


          The most effective way to reduce the size of the accel logs is to reduce the IMU logging (including these ACC and GYR messages).  The latest beta mission planner has checkboxes on the standard params page so you can more easily set the individual bits.  IMU (50hz accel/gyro data) should be checked but IMU_FAST (400hz) and IMU_RAW (>1khz) can be unchecked.

          The downside of turning off the IMU_FAST (400hz) is that if there's an EKF problem we probably won't be able to use the logs to figure it out precisely what went wrong with the EKF. So we can still do regular analysis of crashes (i.e. non EKF related issues) but EKF related issues will be harder.

          For the final release we will reduce the IMU logging to 50hz by default (i.e. IMU_FAST, IMU_RAW will be off by default).

  • A little bit of topic but as I am on my first Pixhawk and 3.3RC7...

    I recently bought an external led and usb board (not from 3DR as they were out of stock)

    My problem is that if I connect it to the I2C port or as the only one on the I2C splitter the led works ok, but as soon as I connect the compass (or anything else on the I2C splitter) it stops working.

    The only thing I found about the problem was a faulty splitter, so I tried with two more but with the same result.

    Any clue what could be the problem?

    • Developer

      It could also be a power issue.  Maybe the flight controller doesn't have enough power for both devices.

      • Randy,

        I do have a two battery setup on the 650sport (for the video stuff), will try to power it from the second battery.

    • I think that i2c LED has the same i2c address as your compass. 

      • Artem,

        Is there a way I could change it (on a compass)?

        Its a compass/gps M8N combo.

        • As far as I know nope.

          But as Randy mentioned it could also be a power problem, however I think if it is the case, than it would also power down the whole 3.3v line on the FC board meaning that your gyros, acc and the onboard compass would be malfunctioning.. Also, as far as I know most of the m8n GPS/mag combos are powers through the 5v line of the GPS serial port,,, 

          • You are right.

            I have connected only the SDL/SCL/Ground wires from the compass to the I2C.

            The power is coming from the GPS port.

  • Something of possible interest. Frame- Hoverthings Flip FPV w/ 2212 980kv Sunnysky's. I have been flying a 3s setup with 11x45 HQ MR props for a while now. Last night I switched over to a 4S setup with 9x43 HQ MR props. IMU1 is nearly identical with either setup but the big difference is in IMU2. With the 3S setup, IMU2 is sometimes very erratic. So far (only a few flights), the 4S setup has IMU2 in check. I still have some tuning to do, etc..., but just thought I'd toss this out here as something of possible interest.




    • T3

      To me the relation between the two looks more or less similar. 

      But what is interesting is that IMU2 is that much higher. On my setups it is higher as well but only a little. Most probably this is also related to a specific frequency. 

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