Welcome to PhantomPilots.com

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

Phantom not locking in satellites? Try this...

Discussion in 'General Discussion' started by ericty, Dec 9, 2013.

  1. ericty

    Joined:
    Oct 7, 2013
    Messages:
    163
    Likes Received:
    0
    Was having trouble getting the required 6+ satellites and home lock flashing green during the power up sequence. It would just flash yellow and red. I did the compass dance 3 times and the light would turn green, but it would just stay green...not flashing...just solid green. I was not comfortable with the situation so I did not even attempt to fly. Emailed my retailer and after the second email with still no change he suggested I do the following:

    1. Do a normal power cycle
    2. Hold my cel phone directly over the compass (in my case it is within the shell in the center) for 30 seconds or so.


    After about 30-40 seconds the red and yellow flashing changed to the red and green flashing. It worked!! Took it outside, did the compass dance and everything was normal. Pretty awesome I think.

    Disclaimer: although this worked for me, it may not for you, so don't hold me responsible if something goes awry in your situation ;)

    **Also note that my Phantom has the Naza v2 controller + GPS with the compass integrated into the GPS antenna under the shell. Consequently, there are two wires that protrude out of the front leg openings on my craft, as opposed to the standard compass that is fastened to the rear leg.
     
  2. phantomflyer

    Joined:
    Nov 18, 2013
    Messages:
    244
    Likes Received:
    0
    Location:
    New Hampshire
    Was having trouble getting the required 6+ satellites and home lock flashing green during the power up sequence. It would just flash yellow and red. I did the compass dance 3 times and the light would turn green, but it would just stay green...not flashing...just solid green.

    Something doesn't sound right about that at all, Sounds like user area from the start. If you had your switch on GPS mode it would flash green and red not yellow and red! Plus when you did your calibration "The Phantom Dance" if you look in the DJI Manual you'd have seen that a solid green means that it was ready for the vertical part of the dance! So either you skipped that part or you did it wrong like maybe upside down, I think you may have tried this cell phone idea while doing things the right way but contributing it to the cell phone idea!! Yellow and red may have meant it was in ATTi mode, I don't know this for sure but just taking a guess seeming how they tell you to keep cell phones away from unit!!!
     
  3. ElGuano

    Joined:
    Sep 4, 2013
    Messages:
    2,219
    Likes Received:
    4
    Yeah, I'm kind of scratching my head at this post too. I have no idea what the mechanism would be for something like this to work. Plus, on a Phantom the compass on the leg and not the shell, but that "which in my case is in the shell" comment throws me off--is this heavily modded?
     
  4. kenskid

    Joined:
    Aug 3, 2013
    Messages:
    146
    Likes Received:
    1
    WTH?

     
  5. Driffill

    Joined:
    Jun 14, 2013
    Messages:
    529
    Likes Received:
    3
    When I fire my phantom up, on my OSD data it tells me the number of GPS satellites in connection with the phantom . . . Funnily enough, not long after connecting the battery the OSD shows anywhere from 3 to 11 satellites, however, once the phantom has warmed up and compass dance etc is complete, I still get a red flash or two after the "GPS Mode" indicator? Even with 10 plus sats showing on the OSD!
     
  6. phantomflyer

    Joined:
    Nov 18, 2013
    Messages:
    244
    Likes Received:
    0
    Location:
    New Hampshire
    2. Hold my cell phone directly over the compass (in my case it is within the shell in the center) for 30 seconds or so.

    I think he's assuming that the compass is located in the shell because the wire from what we know as the compass runs to the GPS unit located at the inside top of the Phantom! Hopefully he didn't shove the actual compass inside of the unit because then he'll really have problems getting it to work right, lol or is he even talking about a Phantom in the first place?
     
  7. ericty

    Joined:
    Oct 7, 2013
    Messages:
    163
    Likes Received:
    0
    Nope. Absolutely not. I've had the Phantom for a few months with more than a few flights, and I know the procedure for compass calibration. Lights were flashing red and yellow, did the horizontal calibration, light turned solid green. Did the vertical calibration, light stayed green.

    As I said, it may not work for you but it did the trick for me...and it's not something I came up with so someone much more experienced with these things suggested it, I tried it and it solved the issues I had.
     
  8. ericty

    Joined:
    Oct 7, 2013
    Messages:
    163
    Likes Received:
    0
    Phantomflyer - you are correct. I did assume the compass was located in the inside top of the Phantom based on what my vendor told me. I have two Phantoms. My first one has the compass attached to the leg. The second one, which I bought from another vendor, had no compass attached to the leg. When I inquired what the difference was he gave the following explanation:



    So yes, as a newbie I took the suggestion of my vendor and did the cel phone trick and it solved my issues.
     
  9. ericty

    Joined:
    Oct 7, 2013
    Messages:
    163
    Likes Received:
    0
    I am at a loss to explain it as well. I'm sure many of you are seasoned RC enthusiasts with lots of knowledge on the workings of these crafts. I concede to your wisdom. I just thought I'd share something that helped me solve a particular issue. I can't explain how it worked, but it did for me. So if it can help someone else then cool.

    My vendor did say that I could also try using a magnet, much like Colin Guinn does in his tutorial about fixing a whacked out compass. Maybe the cellphone method is similar?
     
  10. ElGuano

    Joined:
    Sep 4, 2013
    Messages:
    2,219
    Likes Received:
    4
    Eric,

    Have you hooked up your Phantom to the Assistant and viewed your compass settings in the IMU calibration screen? If you're getting compass errors that can be affected by a cell phone, it's likely they're already quite out of whack and on the very edge of the recommended compass raw and mod values.

    Also, there's a reason DJI puts the compass on the leg of the Phantom rather than use the combo GPS/compass puck that comes with a standalone NAZA--there's no GPS stalk on the Phantom to elevate the unit, and the compass is too close to the electronics. In fact, that may be what is causing your compass calibration error to begin with. I've heard of no vendors that take this route with the Phantom, and it's something DJI certainly doesn't do. Interesting fact pattern nonetheless.
     
  11. ericty

    Joined:
    Oct 7, 2013
    Messages:
    163
    Likes Received:
    0
    Hi El Guano,
    Yes, I've hooked up the Phantom to the Naza and even done the full advanced IMU calibration. All the parameters are spot on. FYI - my initial problems (not getting any GPS confirmation) started after I updated the Naza assistant software and then followed the instructions ("for Phantom owners") to download and install the 'Default settings" for the Phantom. Things went crazy, I think because my radio is the Futaba 8FG rather than the OEM radio. Anyway, the radio would not talk to the Naza software at all - none of the sticks responded on the software when I moved them. I really thought I was screwed. I then hit the 'Reset to default' button in the Advanced menu and then the radio started working. However, the next day when I was preparing to fly that's when I could not get the GPS to lock. A day later and about 6 emails to my vendor, that's when the cel phone trick was suggested. Like I said, I don't know how it worked, but it did. I've taken it up three times so far and it seems to be working fine (knock on wood).
     
  12. deluge2

    Joined:
    Jun 19, 2013
    Messages:
    117
    Likes Received:
    2
    Well had to read the whole thread to fully understand the situation here. As you noted in your initial post, this may or may not work for others. Since this method was suggested, apparently, by you dealer, it might be interesting to ask what the known or presumed mechanism is by which this works. Is it indeed analagous to using a magnet directly on the compass unit when calibration is not possible (ie Colin Guinn's video)? If so, what is the source of the magnetic field? Also, you might want to edit your initial post to make clear that this worked in a 'non-standard' Phantom configuration as regards the location of the compass module. If this works via influencing the compass module, then it would need to be done differently of 99.999% of Phantom users since the compasses are on the leg.

    Steve

     
  13. ericty

    Joined:
    Oct 7, 2013
    Messages:
    163
    Likes Received:
    0
    I sent an inquiry to my retailer to elaborate on this.

    Good suggestion. Done! Thanks Steve
     
  14. LeoS

    Joined:
    Nov 25, 2013
    Messages:
    747
    Likes Received:
    1
    I think the IMU may just take longer to initialize after being reset to default.

    The dealer suggesting a smartphone on top of phantom is probably to verify that position can actually get the necessary gps signal. The phantom actually getting signal after that exercise is unrelated except for the extra time you've allowed it to have from doing the smartphone exercise.

    Come on guys, be scientific! Let's not regress to superstitions and weird sciences now...
     
  15. ericty

    Joined:
    Oct 7, 2013
    Messages:
    163
    Likes Received:
    0
    Here's what my dealer's response was to my inquiry about this whole thing:
     
  16. ElGuano

    Joined:
    Sep 4, 2013
    Messages:
    2,219
    Likes Received:
    4
    To be honest, that doesn't really make any sense to me at all. Why would a cell phone trick the compass in that way. And the dealer's description doesn't jibe with what you described in your first post, kind of the opposite, actually.

    I don't know everything about the NAZA or compass (heck, I hardly know ANYTHING about both), but this whole thing just sends up red flags all over the place. I'm very curious to find out more.
     
  17. ElGuano

    Joined:
    Sep 4, 2013
    Messages:
    2,219
    Likes Received:
    4
    Great idea. Let's get methodical.

    I hooked up my Phantom to Assistant and took a screenshot of the compass settings:

    [​IMG]

    Next, I held my cell phone (iPhone 5s) directly to the compass. It varied a little bit, not really noticeably, until I held the very top of the phone (the edge with the power button) to the compass. Then the values went crazy:
    [​IMG]

    Check out the mod value. What you don't see in this picture is the little warning sign and pop-up that shows up in the bottom right corner warning me of a "compass calibration error." So, OP's story checks out! Right? Hmm, not so fast. I turned the cell phone OFF (no electromagnetic interference). And held it up to the compass again:

    [​IMG]

    Huh, waddayaknow. Same effect. New hypothesis: we're not really dealing with the cell phone here at all. The compass is reacting to the magnets in the speaker at the top of the phone. So I tried holding the bottom of the phone where the speakerphone and mic are (more magnets). Mod flies up to 6-7000.

    So I think that's it. Technically, the dealer's not wrong. The cell phone is both an item that cleverly has the components needed to interact with the magnet that everyone has with them at all times even in the field, and also a red herring since it has nothing to do with the EMF of the phone and only the ferrous parts of the speaker/mic. You could probably do the same thing with a piece of steel. As to whether it "throws the NAZA into fault," or just kind of randomly changes values until it might at some point randomly start working, I don't know. The calibration itself is supposed to serve that purpose.

    Thoughts?
     
  18. ericty

    Joined:
    Oct 7, 2013
    Messages:
    163
    Likes Received:
    0
    Bravo El Guano! That certainly makes sense. In defense of my retailer, he did say "or you can use a magnet". Not everyone carries a magnet around, but a cel phone with built in speakers?? That was a terrific scientific approach. I shall remove the original post lest it create additional confusion.

    Thanks for tolerating me and this post!! Peace everyone!
     
  19. ElGuano

    Joined:
    Sep 4, 2013
    Messages:
    2,219
    Likes Received:
    4
    No need to remove the post, I don't think you posted any misinformation, and we're all here to learn. The journey is half of it.
     
  20. LeoS

    Joined:
    Nov 25, 2013
    Messages:
    747
    Likes Received:
    1
    @ElGuano: *standing ovation*
    I didn't expect the speakers magnet on smartphones would be that strong!