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Losing GPS lock..

Discussion in 'Phantom 2 Discussion' started by river_rat_tx, Mar 10, 2014.

  1. river_rat_tx

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    So just about mid way thru my second flight with my p2 i lost my GPS lock and the green lights turned yellow while still in the air and my s1 still in GPS.. no harm done as it was close to the ground when the wind started to make it drift and i just set it down, turned it off and back on and let it lock on again and it stayed connected for the rest of my flight.

    What could have caused losing my gps lock?

    Im in a rural area, let it lock on initially and didn't start it up near any thing that may mess with the compass that I'm aware of. Any ideas?


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  2. OI Photography

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    Have you tested it on the bench since?

    Could be caused by a failure of the GPS module or its connections, might want to double-check the cables at least.
     
  3. river_rat_tx

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    is that the same as plugging it in to the assistant software? i did check the connection on the landing gear and it seemed fine


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  4. juche1777

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    Just a shot in the dark, were your TX batteries fully charged?
     
  5. river_rat_tx

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    yep popped some fresh ones in while the rechargeable ones from B&H were on the charger


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  6. OI Photography

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    I was just wondering if you'd powered it up again since that flight to see if it'll go in to GPS mode again.

    The cable from the compass on the leg ends up connecting to the GPS module inside the Phantom, mounted in the top of the shell. Another cable then goes from that board to the NAZA flight controller. A fault in that GPS board or its connection to the NAZA could cause the problem your seeing.

    You can also try re-calibrating your transmitter in the NAZA software at least, it's possible the output of the switch has wandered past the limits of the "fully-up" position.
     
  7. river_rat_tx

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    just took it for another flight, it locked on and didnt have any problem. I'll keep an eye on it thanks for the quick replies and the help

    Im immobilized right now (fresh out of ACL surgery) and dont have access to my computer but will soon and I'll let yall know how calibrations go


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  8. ianwood

    ianwood Taco Wrangler
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    Hard to tell but it could be that you had the minimum number of satellites at take off and one or more went out of LOS before others were acquired.
     
  9. river_rat_tx

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    that could be it! im pretty sure i got the yellow/green flashing sequence that means exactly 6 satellites and then started flashing slow green


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  10. river_rat_tx

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    I went for a fly earlier and may have pinpointed the issue. i let it lock on sitting about 10 feet away from me on a concrete pad no issue. when i went over just to make sure i was getting flashing green and it was until i picked it up. when i did that it went from flashing green to a yellow every third flash to more flashing yellows like it lost satellites. Could this be caused by my metal crutches?


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  11. ianwood

    ianwood Taco Wrangler
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    Concrete is bad if it is reinforced with steel rebar. It will throw off the compass. If that is not the case, it could be that the particular area you are in has a limited view of the sky and is therefore only getting the minimum satellites. When you pick it up you change the Phantom's view of the sky. To confirm this, find a location that is far away enough from high walls or tall trees so that the Phantom has a pretty unobstructed 360 degree view of the sky almost all the way to the horizon. A football field is a good option. Calibrate the compass just to be sure it's not part of the problem.

    The only other thing I can think of is the possibility of a loose connection between the GPS and the main board.
     
  12. mikeboruta

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    Another possibility is that the S1 switch on your transmitter isn't working correctly. I am in Naza mode and I just realized today that when my switch is in the fully up position I can apply slight pressure to it and it will switch to ATTI, even though I don't physically move the switch down to the middle position. I verified this by connecting my phantom to my computer and doing a transmitter calibration. Sending it back to DJI tomorrow. Here is a link to a thread which discusses this problem:
    http://www.phantompilots.com/viewtopic.php?f=7&t=4188&p=29296