GPS No Lock and Magnetic Declination

Discussion in 'MōVI M5' started by sandeep nandy, Nov 18, 2015.

  1. sandeep nandy

    sandeep nandy Member

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    Hi,

    I kept my M5 for 10 min outdoor and GPS Lock is still greyed out as shown in my Mac. My iPhone can detect excellent number of GPS. What could be the possible reason?

    Issue 2: When enabled Compass in heading assist and the magnetic declination set at 0 and then at 11 (officer, Victoria, Australia) - it sits in few degree left angle from centre after boot up. What could be the reason?
     
  2. Mateusz Hajdziony

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    I am having similar issues on the M10 but the other way round! Most of the time when I connect to the Movi with the Android I am getting 0 satellites and the GPS Lock is greyed out. Connecting to the Macbook will show the correct number of satellites. The funny thing is - without rebooting the Movi, I can connect with smartphone, get 0 satellites and grey GPS Lock, then connect with laptop and see the correct number of satellites and GPS Lock as OK, then reconnect with smartphone and everything is working fine (until reboot). Strange thing...

    As to the Movi not having the correct heading - you can trim it using the Pan Trim setting. Remember that sometimes the pan axis will drift (over time) if the Movi sits on the stand, but once you grab it and actually use it - the pan axis will go back to normal.
     
  3. Steve Maller

    Steve Maller UAV Grief Counselor

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    Is your MōVI on a copter? If so, something on the copter might be causing interference or blocking enough of the sky to prevent the MōVI from getting a proper GPS lock. Does it show any satellites? Do you have the improved antenna on the MōVI? I found that this upgrade improves the MōVI's performance considerably.
     
  4. Mateusz Hajdziony

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    For me it happens even if the Movi is on the stand, in open field, no interference.
     
  5. sandeep nandy

    sandeep nandy Member

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    I just had the Movi for less then 48 hours .. but i have been tuning my multiple lens, test and save the initial settings for each lens handheld. Not once, indoor or outdoor in my backyard there is any sign of GPS. The Freefly configurator in Mac shows GPS no lock, zero sats.
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Sandeep: It's *just* feasible that there's radio frequency in the area that's causing the problem -- if you have a smart phone, or a GPS unit that can get a 3D lock on the GPS, then I think it's time to open up a support ticket by sending email to support@freeflysystems.com.

    Andy.
     
  7. sandeep nandy

    sandeep nandy Member

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    update: GPS worked out in handheld mode today - 6 sats found. Is there any documentation which says about the min. number of sats required for the gimbal to avoid horizon drift?
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Sandeep: I don't recall seeing any documentation that specifies the minimum of satellites required. Did you get a GPS OK status? I believe that indicates a 3D lock.

    Andy.
     
  9. sandeep nandy

    sandeep nandy Member

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    Yes, GPS Ok, Lock on, Sats =6.
     
  10. Mateusz Hajdziony

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    6 sats is not that much when it comes to accurate positioning needed in multicopters. I would assume that it is the case with gimbals too, since you need immediate and accurate feedback about the horizontal speed of the system to avoid drift. That being said, you will always get some kind of drift, even with 10+ GPS sats, without feeding the gimbal data from your flight controller. At least initially when doing an aggressive maneuver your horizon should drift a bit and then settle back to normal. Still, it's better with GPS that it is without - I have previously used Alexmos based gimbal without GPS and the horizon drift was really bad and rendered huge percentage of footage unusable.

    If you are talking about handheld use - you shouldn't see any drift because the acceleration forces are not strong enough, unless you're using it handleld in a real size heli or fast car.
     
  11. sandeep nandy

    sandeep nandy Member

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    I seen Gremsy is working on canbus cable, actually released a week or two ago which communicates with DJI A2 flight controller to avoid horizon drift.

    https://www.gremsy.com/canlink
     
  12. Mateusz Hajdziony

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    I've seen that too! They must have spent a lot of time to reverse engineer the CAN signal from the A2. Would love to have a Gremsy gimbal and do a side-by-side comparison with the Movi.
     
  13. sandeep nandy

    sandeep nandy Member

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    A quick test : still little wobbly and drift at aggressive yaw:
     
  14. Bryan Edmonds

    Bryan Edmonds Chief MōVI Whisperer

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    To help the MōVI maintain horizon during quick acceleration on a multi-rotor (or shooting out of the side of a vehicle), try changing the Heading Assist to GPS. You will find this setting in the Freefly App, under the Expert section.

    More satellites are definitely better, as mentioned above, but changing this setting will put more importance on the acceleration readings from GPS.
     
  15. sandeep nandy

    sandeep nandy Member

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    DJI S1000+ and MOVI M5 Stability Test with Pana GH4+Oly 12mm = All looks good :)
     
  16. Mateusz Hajdziony

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    Looks better now but your footage is still shaky. That's exactly the same kind of shakiness that I cannot get rid of from my footage with M10. :(
     
  17. sandeep nandy

    sandeep nandy Member

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    The lens is too light. I am not adding weight or putting the 12-35mm lens. Will tune it more today using the software .
     

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