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Drifts when in GPS mode

Discussion in 'Phantom 2 Vision + Discussion' started by GS81VETT, Jun 17, 2015.

  1. GS81VETT

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    Hi Guys,

    New Phantom user here. Just bought a used Vision 2+ and love it. I had a small issue when the unit was on the ground and tipped over a bit hard.

    I re-calibrated the unit in the DJI assistant software and all seems to be good, I also took off the shell and inspected for any loose connections and all looked good.

    So now when I fly it in GPS mode it goes all over the place when it is about 10-15 feet off the ground. It used to stay almost completely still. But it will steady out once it is up over 25 feet.

    She does not feel as stable as it did before the minor smack on the ground.

    Thanks in advance for your help.

    G
     
  2. phantom13flyer

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    Did you inspect the props ? Maybe try putting a different set on.
     
  3. GS81VETT

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    Brand new props.
     
  4. N017RW

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    Do you get the proper green rear arm LED indications that you have GPS lock before take-off?

    Saying it gets more stable when rising higher seems to indicate it's getting more sats. once elevated or you are in some type of turbulence when lower.
     
  5. marg2

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    Recalibrated by doing a full IMU cal?
     
  6. GS81VETT

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    Yes on the rear LEDs being green. Also I run the cal for the compass before each flight and I did run an advanced re calibration of the IMU (I have not run one after enabling the Naza-M) I will do it again.
     
  7. BlackHawk388

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    Just so you have the info I worked so hard to discover.

    1. Changed setting in Vision from NAZA-M to Phantom.
    1.1 Under the Tools tab, I clicked on "Reset BTU".
    2. Powered down the drone via the battery.
    3. Turned off the TX and WiFi.
    4. Shut down the Vision software.
    5. Disconnected USB cord from laptop.
    6. Restarted laptop. (Not sure if this had any affect or not, just good GP).
    7. Removed battery from the drone.
    8. Waited about five minutes.
    8.1 Never got the overheated MC message again. I assume this is from the battery being removed for that five minute period as well as the fan on the drone itself. Hey, the fan felt good to me as well!
    9. Reinstalled battery in the drone.
    10. Turned on the TX and WiFi module.
    11. Turned on the drone via the battery.
    12. Plugged the USB cord into my laptop.
    13. Started the Vision program.
    14.I was immediately notified that an "Advanced Calibration" was required.
    15. The drone had not yet acquired a GPS lock. So I waited until it did so. Not sure if that is a required step or not. Just relaying information.
    16. I then set it back to NAZA-M.
    17. I then went to Tools again and then the Advanced tab below. I then clicked on Advanced Cali. The process took less than two minutes to complete.
    18. I turned off the drone, then the TX and WiFi module.
    19. I then took the drone outside with props installed and did the DJI Dance for a normal calibration.



    After I did all of that, my drone has been rock solid. I won't go into the hours I spent figuring all of that out. I'm pretty meticulous about these things. If it helps you in the slightest, then it will have all been worth the effort of writing it down.

    Good luck!
     
    SnoozeDoggyDog likes this.
  8. BlackHawk388

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  9. GS81VETT

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    Thanks. Sounds like a total reset......Good idea Ill give it a shot tonight
     
  10. landmannnn

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    Before you do that check you haven't damaged a motor, spin them by hand to check for rough spots or a bent spindle.
     
  11. GS81VETT

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    Yes agreed I have not checked the motors that could be part of the issue.

    Thanks
     
  12. BlackHawk388

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    That's exactly what it is. I'll use that terminology in the future. It's a total reset and relearning of the internal electronics via your particular environment.
     
  13. BlackHawk388

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    Here's my video I took just a few minutes ago to show how stable the P2V+ V3 is after doing the BTU reset and relearn.

    Extremely stable.

     
  14. BlackHawk388

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    The winds vary from still to 20mph. The structure of my house and the fence just goes to show how very stable this thing is.
     
  15. BlackHawk388

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    I've got another one uploading right now. It will be even more indicative of the stability. Give me a moment and I'll link it.
     
  16. RoyVa

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    Key to proper IMU calibration is the copter being completely level front to back and side to side. Use pennies, credit card, or even paper to shim under the landing gear to get it perfectly level. Doing this will get you the best stability and hovering action.
     
  17. BlackHawk388

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    Very true. I use a small, wooden printer stand I've used a digital level on. It's leveled with business cards I no longer needed taking up space in my wallet. I also used that table to balance my props. Another thing is I usually have a fan and ceiling fan blowing. These should be stopped as well during this process.
     
  18. StevenQX

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    What is the reset BTU for?

    As far as i know is to reset the BTU unit on phantom 2, useless in phantom 2 vision plus...
     
  19. BlackHawk388

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    I have no idea why resetting BTU (Bluetooth Unit) worked in my particular situation. I had changed to NAZA-M mode and couldn't get the advanced calibration to complete. It kept hanging at roughly 90% complete. Wouldn't complete no matter what I tried. So since Reset BTU is right there, I just thought what the hell, I'll give it a try.

    For some reason, it worked. I've been flying stably in NAZA-M ever since.

    If I had to guess, resetting the BTU forces the bird into needing an advanced calibration. Perhaps it resets the compass in the process which allowed me to finish.
     
  20. StevenQX

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    Anyway to see if it's perfectly calibrated it need to stay still in ATTI mode with no wind, not in gps mode