ArduCopter-3.2.1 Beta Testing

ArduCopter 3.2.1-rc2 (release candidate #2) has completed beta testing and has been released as the official version available through the mission planner and other ground stations.

Changes from AC3.2 are listed below and in the ReleaseNotes:
1) Enhancements:
    a) reduced twitch when passing Spline waypoints
    b) Faster disarm after landing in Auto, Land, RTL
    c) Pixhawk LED turns green before arming only after GPS HDOP falls below 2.3 (only in flight modes requiring GPS)
2) Safety Features:
    a) Add desired descent rate check to reduce chance of false-positive on landing check
    b) improved MPU6k health monitoring and re-configuration in case of in-flight failure
    c) Rally point distance check reduced to 300m (reduces chance of RTL to far away forgotten Rally point)
    d) auto-disarm if vehicle is landed for 15seconds even in Auto, Guided, RTL, Circle
    e) fence breach while vehicle is landed causes vehicle to disarm (previously did RTL)
3) Bug Fixes:
    a) Check flight mode even when arming from GCS (previously it was possible to arm in RTL mode if arming was initiated from GCS)
    b) Send vehicle target destination in RTL, Guided (allows GCS to show where vehicle is flying to in these modes)
    c) PosHold wind compensation fix
    d) prevent infinite loop with do-jump commands pointing at each other
    e) pixhawk memory corruption fix when connecting via USB
    f) vehicle stops at fence's alt limit in Loiter, AltHold, PosHold (as it did in AC3.1.5)
    g) protect against multiple arming messages from GCS causing gyro calibratoin failure

Thanks to Raph for the video.  This is actually a video from AC3.2 until we have one specific to AC3.2.1.

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  • I installed the official release of ArduCopter V3.2.1 on my Pixhawk. I was testing it by spinning my quad (rapidly) in a stationary position in loiter mode. When I stopped spinning it would start toilet bowling. I switched to alt hold and let it settle down then switched back into loiter and everything was fine. I tried this 2 or 3 times with the same result.


    log file attached


  • I found this on U-blox site 

    GPS Antennad RF Design considerations for u-blox receivers - application note

    maybe useful to people that plan to change the ground plane

    • Thank you @Richard!

      I'm beginning to understand more and more on these units.  My first M8N was a 40mm antenna sized unit, but the latest ones I purchased are 25mm.  So I now need to do a side by side comparison to see for myself that the 40mm antenna is better.  However, the PCB board also needs to be larger to accommodate the ground plane.  Without the larger ground plane, it very possible the back lope from signals or EMI interference can degrade front lope signal quality thus reducing overall performance.

      Please all, respond to my post here

  • So I read an interesting article about GPS antennas called "Adding a GPS Chipset To Your Next Design Is Easy".

    A few points to bring up that I have concerns with dealing with my M8N antenna.

    1.  Active vs Passive Antennas.  Two paragraphs within the article describes the difference between Active and Passive antennas.  According to CSG Shop's specification for the NEO-M8N it comes with a low-noise regulator and RF filter built-in.  So I'm assuming that it is a active antenna. 


    2. Antenna's requiring adequate plane.  If I read that document correctly, these GPS modules may require a GPS plane as they are installed on a PCB that does NOT have 40mm of side to them.

        Quote: "Generally, patch antennas in the 15- to 25-mm size range with a least a 40-mm (on a side) ground plane will give the best performance in portable equipment, but this may be too large for your application.  This could force you to look at smaller antenna topologies such as linear chip antennas."


    3. The next concern is to mitigate the noise interference from FC, ESCs, and PDB.  Since my Y6B is set up with a clam shell cover and my M8N is attached under and close to the all the electronics, I may need to develop a shield "ring" connected to the shield can and then connect that ring to RF ground through an inductor at a single point.  


         Quote: It's common in VHF and UHF RF shielding to connect all points of the shield can to the PCB's ground plane.  This can be a mistake at GPS frequencies, since the open-air wavelength of a GPS signal is so much shorter than UHF.  Depending on the size of the shield can, if there is current flow across the can, the shield can will be able to resonate near GPS frequencies resulting in interference or de-tuning of the GPS RF.


    By developing a shield "ring" connected the shield can and the inductor, the inductor will filter any EMI-induced current flow.  The ring connected to the shield can will prevent any current flows or resonation issues. 


    I'm not an electrical engineer and need guidance from those out there who are.  Did I interrupted this correctly? and if so I could use some help with developing the "ring".




    • T3

      Hi Doug,

      I also think that this is a very important topic. What about opening a separate discussion so that all information is in one place and does't get lost in another discussion?



      • Created this in its own discussion area.

  • @Craig Elder

    You have no idea how many questions you answered in that one paragraph about the M8N.

    • Developer

      You're welcome. I have been trying to explain this situation to people for months. 

      • I appreciate the information on the GPS interference.  In all my blogging and reading, I don't think I ever read a better explanation about the M8N let alone all the different types folks have been using.


        Suggestion that 3DR post a Blog on this subject and possibly providing a detailed analysis of the M8N, Lea-6H, M7N, and any other GPS on the market being used on drones. 


        People want to know and I personally bought and tossed GPS that I felt are not meeting the mustard and that can get quite expensive for some.

        • I would be building a ground plane for the M8N ASAP, but because the active antenna on the M8N is not detachable can I place the entire module on the top of the plane and connect the shield to ground?? 

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