Arducopter Beta 2.0.38



Please note that the initialization of Gyros was requested to move to the Arming function. This had the unintended consequence of making the Ground Station report erroneous attitude until the unit is armed at least once. This is changed already in the next version 2.0.39 which is still in development. Thanks.


This is a nice update and is recommended for everyone. I've gotten a half dozen flight in with it and have had good success. I'll be incorporating some of the ideas mentioned in the suggestions post over the next few versions. 


What's new:

I reworked the startup so it's much faster. Also, a feature a lot of folks wanted, calibrating the IMU at first Arming is in there. If you hand launch, please do your first arming of the motors on the ground.

I enabled a mode filter for sonar. Not too thoroughly tested performance wise, but it does work. (note, if you rely on the rangefinder class, you must rework your code to be compatible.)

RTL bugs are squashed and it's flying really well now.

Added a special filter in the PID for the derivative term to get rid of the alt hold and loiter issues from noisy sensors. 

Added a completely experimental mode called circle. It will by default spin the copter in a 10m circle from the point at which it was engaged. And it will Yaw towards that point at all times.

Yaw while navigating happens at quarter speed, which was problematic before.

Roll and Pitch Imax are higher 5° than before (.5°)

Logging seems to work now. Please erase the log after installing.

Everything else is mentioned on the SVN.


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  • When will this verison be in full release status and updateable via Ardupilot?



  • Cool. Thanks for the answer.

    Is 0.37 the "old way"? Or the "new way". I only got my quad back in the air last night after a month of no flying, so I'm using 0.37 which was the latest available via the Mission Planner.




  • Developer
    Ground start nulls the gyro offsets. Barometer is also calibrated with ground start.
    Level is stored during initial setup with the mission planner or in the field by a special Yaw command. It's not initialized with each flight.
    The old way of starting required the copter to be still right after plugging in. The new way allows you to init at first arming of the motors.
  • I'm looking around for a good description of the changes to the ground start logic, and the differences between 2.0.37 and 38. I haven't found anything specific so here goes:


    -What is the exent of the ground start alignment? Is it only nulling gyro offsets? Or is it actually taking the current quad attitude as a new "level" at each start?

    - If it's recomputing "level" at each start, how careful do I have to be that the quad is level during arming? I could see an issue here that most flying sites don't have a surface that is exactly level. Won't this cause drift during hands-off flight if you happened to arm the quad on the side of a slope?

    -What happens when you plug the battery in vs. when you arm the motors. i.e. do I need to have the quad placed on the ground when I plug in? Can I plug in the quad while holding it so long as I put it down before I arm it?






  • @chris, yes i have mountes my sonar like wiki.

    but i have test no sonar, same problem :(

  • I have a rework station plus I have access to the oven at Nicosia Uni. I could even make the entire board there. 

    The reason that I want a spare board is to make an experimental one with different gyros. It makes sense to use the parts from the damaged one. 

    I will however also order a new set from you later today. 

  • 3D Robotics

    Denny: I'm afraid we don't sell bare boards, but you can have a board fabricated from the Eagle files. But how would you put on all the components?

  • 3D Robotics
    mc_don: have you mounted your sonar sensor on an arm as instructed in the manual?
  • i have new problem

    when i go to hold atl mode,  the QC is go UP fast.

    1st time i test using sonar. i think my sonar error.

    2st test i disable sonar. but i have same problem

    i have test my sonar and altitute using CLI and like oke.

    and i set my ch7(RX) is about 1ms.

    can you solve my problem?

  • OK.... I was getting crazy. I confirm that the column "sonar" corresponds to BARO. Column "Throttle Out" is really the sonar data as Jason indicated. Below is a plot from a test maintaining the quad fixed by hand on the floor, and then at 1m. The sonar signal (red) is quite good. The baro follows more or less the sonar.



    So, its clear now:  the sonar is reading very well now, but the control is not very good yet (was much better in v.37). See the plot below for a alt_hold at 1m all the time. It oscilates slowly, and I can´t get good PIDs (same hardware was perfect ATL_HOLD in v.37 with double values of P & D, the default ones).

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