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Compass Caution!

Discussion in 'Phantom 2 Vision + Discussion' started by henryten, Mar 26, 2015.

  1. henryten

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    On my DJI Phanton2 Vison+ :

    When calibrating the compass, it's working for the horizontal component (LED goes green), but when I spin the vertical component, all I get is the dreaded RED light indicating compass calibration failure. :cry:

    If I ignore the warning and wait for GPS lock, there are no further (obvious) problems. I can see the status on my laptop and iPhone - all clear. IMU looks good and there is no indication that I need to calibrate the compass. And yes, it seems to fly fine in GPS and Atti Naza (and Phantom) modes ... so far.

    I've reset everything, recalibrated, and can't figure out the problem - or if I even have a problem.

    Sound familiar to anyone? Or did I miss something in the manual?
     
  2. MapMaker53

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    Make sure you are spinning vertically with the battery up. That's the only thing I can think of.
     
  3. henryten

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    Yep - checked that (and even tried doing it battery down, just for the hell of it). No joy.

    Thanks,
    Henry
     
  4. Meta4

    Meta4 Moderator
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    If it's flying straight (esp in RTH) then just leave it.
    Doing a compass calibration for every flight can introduce the problem of getting a bad calibration.
    If it aint broke ....
     
  5. N017RW

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    Have you check the compass values in the assistant?

    It may need degaussing.

    You can google that for demo vids
     
  6. snowghost

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    Try spinning around with your whole body. I had same problem with just spinning the Phantom in place.
     
  7. henryten

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    Thanks all for your replies.
    Snowghost, I have tried both methods of rotation, but if you had the same experience, perhaps i'll give it another try.

    Degaussing was my next step, but I'm worried of messing up something else. And the Assistant shows NO ERROR. Does anyone have experience with demagnetizing the DJI compass?

    Meta4 says that calibration can actually INTRODUCE error (and just stop worrying). I haven't tested RTH yet - if THAT works, I'm taking Meta4's advice!
     
  8. HeisenbergAR15

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    I have been having the same problem your talking about and have just continued to use it without issue... Would be great to find a solution or explanation... Only difference is when I get the green spinning horizontal and then go vertical I never get a green but I don't get red either it just blinks the yellow orange color
     
    The English Guy likes this.
  9. Andy1

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    I had this problem, all worked fine on 3.08. I upgraded to 3.12 and no way could I get anything but Fast Flashing RED Lights after a Compass Calibration. Turned out to be my 'Bio-Flow' Magnetic wristband causing the problem. Seems that the Compass Calibration is a lot more sensitive using 3.12.
     
  10. dysan911

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    What would be the minimum distance from your last Compass calibration location would you perform another one? Feet, Miles, Country, etc?
     
  11. Andy1

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    I just do it every time I fly.
     
  12. burlbark

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    Henry, Can you give us an update if everything is working fine? I never got your 2nd call letting me know.

    Jeremy James
     
  13. henryten

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    Okay, I've actually got it fixed - sorry to be slow in replying, Jeremy, just got it confirmed today.

    Backstory: Over a few flights it was getting increasingly unstable and/or frequently overcorrecting. It was NOT fun to fly. Landing it became a gripping adventure.

    The problem was a magnetized compass. I could see the error in the Compass(Raw) "mod" number in Phantom Assistant, Tools. Repeated demagnetizing had accomplished very little, but I kept waving magnets around about 3 cm from the compass, trying to remember my HS physics. Certain moves and distances SEEMED to get better numbers in PA, but I'm no physicist. Eventually it worked (after I got rid of the prop that had been damaged). Running fine now!

    There have been suggestions that compass problems are a major source of flyaways in GPS mode - if the GPS and the compass are out of sync, it sets up a potentially fatal feedback..

    Anyway, the important lesson(s): Keep the compass clear of magnets and keep a small magnet handy. Just not TOO handy, or TOO magnetized.
     
  14. henryten

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    I believe that yellow/orange is one of the normal responses - if it was yellow/orange before you started calibration. As I recall, it means normal ATTI mode (no GPS).
     
  15. pana8888

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    I have same problem too with my Phantom 2 V+ 3.0. I thought it caused by the defect compass component. I keep flying with GPS mode and its work well, but I'm worrying it is a potential problem without have a normal calibration.

    henryten - do you mean keep waving a magnet near the compass and re-calibrate the compass can solve the problem ?
    Not sure if the fixing procedure is same with this:

    Is there any testing we can do to observe the healthiness of the compass ?
     
  16. Lofty Visions

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    Will try this as both my P2V+'s have this issue. Thanks!
     
  17. dysan911

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    I went to a new location about a mile or so from my house and tried to calibrate my compass. Every time the result was the same. Flashing Red which if I'm not mistaken is "Low voltage" or "OTHER". I had a full battery so I had to power off and back on and tried twice more with the same results. I was getting a good HOME LOCK though each time I powered up and about 8 or to 10 GPS locks so I took the bird up and flew for a while without any issues.

    EDIT: FWIW, I also before cycling the power I tried to initiate a new compass calibration by flicking S1 5 times fast up/dn and it did nothing.
     
    #17 dysan911, Mar 30, 2015
    Last edited: Mar 30, 2015
  18. N017RW

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    Regarding your last question...

    Yes connect to the P2 Assistant and observe the values displayed in the proper tab (sorry don't recall exact one, easy to find) If you hover over the "?" it will tell you the nominal or range of values considered aceptable.
     
  19. TeamYankee

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    You'd think that DJI would have addressed this flaw.. the GPS and compass argument.
    If the compass is way off compared to GPS then throw an alert red lights etc..
     
  20. N017RW

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    Not sure what 'way off' refers to.
    The GPS can provide location, ground track, speed, and altitude. The compass provides you heading.

    These really don't compare so what do you mean?