Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Non gps mode moments + log

Discussion in 'Pro/Adv Discussion' started by t2adze, Jan 22, 2016.

  1. t2adze

    Joined:
    Jan 3, 2016
    Messages:
    560
    Likes Received:
    39
  2. Oso

    Oso

    Joined:
    May 19, 2015
    Messages:
    2,535
    Likes Received:
    1,480
    Location:
    Sacramento CA
    I have seen this same issue posted several times in the last 12 days or so. Lots of unusual GPS issues all of a sudden.

    15 GPS satellites, but GPS repeatedly drops | DJI Phantom Forum

    Note - please dont say its the KP index!

    I've brought this GPS issue up in several threads now but it hasn't gotten any traction so maybe its nothing.
     
    #2 Oso, Jan 22, 2016
    Last edited: Jan 22, 2016
    Trackman1 likes this.
  3. Frankc

    Joined:
    Jan 6, 2016
    Messages:
    655
    Likes Received:
    137
    Location:
    Malvern, Worcestershire, England
    Like phone signals some areas have poor GPS reception. My home area is one of them. At one time I got 1 sat connection but that was years ago. Now I have 5 sometimes. But if I go a couple of miles away to my flying area I can get 15+. Go figure. You would think as the Sats are above us pointing down it would not be a problem but I guess your flying into a non or poor coverage area. I would be your still getting GPS but with fewer Sats. I would worry if everywhere you flew you had the low signal but if its only in that one spot Id just avoid it.
     
  4. With The Birds

    Joined:
    Jan 4, 2016
    Messages:
    2,608
    Likes Received:
    742
    Location:
    Australia
    1600 feet up, id be more worried about helicopters than GPS dropping out... Healthy drones suggests controller mode change to ATTI, i wonder how accurate some of these logs are.
     
  5. Trackman1

    Joined:
    Jan 1, 2016
    Messages:
    838
    Likes Received:
    212
    Location:
    Ontario, Canada
    I have been noticing issues with the sats too. This seems to be the time people hit RTH and it's where did my birdy go.
    OP kept his head and flew home.

    I notice he had 10-15 sats at all times. One would think that would be enough. My car and motorcycle gps never complains of lost sat. unless I am in a tunnel.
     
  6. Helijoc

    Joined:
    Nov 28, 2015
    Messages:
    186
    Likes Received:
    61
    I had mine slip into ATTI on one flight. Suspected it was the presence of a metal fence I was standing to close to with my controller and a bad compass calibration because of the same. I am thinking if the compass cannot coordinate its position with the flight controller GPS will error even if you have sufficient satellites.
     
  7. Frankc

    Joined:
    Jan 6, 2016
    Messages:
    655
    Likes Received:
    137
    Location:
    Malvern, Worcestershire, England
    Whats ATTI?

    I wonder if anyone has done a 'both sticks back and in' to switch the drone off in an emergency to drop fast then tried to restart on the way down? Its a thought isn't it? And no I do not want to try it myself :)
     
  8. Helijoc

    Joined:
    Nov 28, 2015
    Messages:
    186
    Likes Received:
    61
    ATTI is basically manual flight mode. It will only hold altitude using the barometer. It is the middle setting on the controller toggle switch. It will not hold position and drift with the wind and lack braking.
     
    Frankc likes this.
  9. Frankc

    Joined:
    Jan 6, 2016
    Messages:
    655
    Likes Received:
    137
    Location:
    Malvern, Worcestershire, England
    Ohhhh I see. I reckon thats what happened to my drone yesterday. The RC went from Green to red warning of weak signal. Promptly went sideways into a bramble bush. Spent the last day fixing the RC to get it back to normal flight. Had to re-link etc.
     
  10. Helijoc

    Joined:
    Nov 28, 2015
    Messages:
    186
    Likes Received:
    61
    You should go to an open area and put the quad in ATTI and practice flying in ATTI. Is a useful skill to have.
     
  11. Draco

    Joined:
    Dec 19, 2015
    Messages:
    36
    Likes Received:
    2
    Location:
    Debary, FL
    My drone has been going in and out of attic the last few times I have gone flying. The first time I thought it was something I did by accident, but it happened a few more times. Glad to know I am not the only having this issue.
     
  12. nix240z

    Joined:
    Jan 8, 2016
    Messages:
    137
    Likes Received:
    40
    Mine did it yesterday on the 3rd flight of the day. This was the first time ever and reported a compass error, never did lose control and after about 10 seconds returned tp GPS mode and landed safely. I am running a new flytrex live 3g and not sure if this caused the problem.
     
  13. Helijoc

    Joined:
    Nov 28, 2015
    Messages:
    186
    Likes Received:
    61
    Perhaps someone here can give a good explanation of how the flight controller, GPS, and compass interact. I don't think that people are losing satellites after having 15+. Without movement the GPS does not know heading unless the compass communicates such. I really think this has to do with a compass error. Perhaps when you are moving the heading between the compass and the GPS do not agree and it defaults to ATTI.
     
  14. alokbhargava

    Joined:
    Sep 28, 2015
    Messages:
    5,142
    Likes Received:
    1,658
    Location:
    San Francisco, CA
    I had noticed switching forth and back to GPS mode only after switching to App version 2.5. Never saw it before. I call it a Geo Bug.
     
  15. Helijoc

    Joined:
    Nov 28, 2015
    Messages:
    186
    Likes Received:
    61
    You know you may be right. My Go app auto updated. Don't have my device handy but will try and determine if the update was before my first experience.
     
  16. Trackman1

    Joined:
    Jan 1, 2016
    Messages:
    838
    Likes Received:
    212
    Location:
    Ontario, Canada
    I think you pretty much nailed it when you say gps does not know direction when not moving. But I think the compass also gives it orientation. When moving the gps knows it's going north. But it may not know it is traveling sideways to the north. The compass would tell it if the front is pointed north, in the direction of travel. At least that's the way I figure it.
     
  17. John Locke

    Joined:
    Jun 26, 2015
    Messages:
    2,956
    Likes Received:
    1,108
    Location:
    Yorba Linda, CA
    Couple weeks ago on my third flight my compass flaked out. Same location all three flights. Had to bring it back in ATTI and recalibrate the compass. Really strange behavior.
     
  18. bighi

    Joined:
    Oct 15, 2014
    Messages:
    454
    Likes Received:
    150
    Location:
    Gibraltar/Austria/Italy
    I get this quite often. Some days it never goes to yellow, others vey often. But I'm in a valley between massive mountains.
     
  19. Helijoc

    Joined:
    Nov 28, 2015
    Messages:
    186
    Likes Received:
    61
    So we are dealing with magnetic orientation as opposed to a direction of travel the GPS reads. Would make sense that in the programming would default to ATTI when the compass is off as relying on GPS the aircraft could be facing any direction
     
  20. WetDog

    Joined:
    Oct 18, 2015
    Messages:
    1,491
    Likes Received:
    640
    Check out ianwood's post on compass calibration. He talks about what the compass actually is and how it works. Thinking it is a typical compass isn't quite right. It is really a 3D magnetic field discriminator.