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GPS and Home Point (Vision App)

Discussion in 'Phantom 2 Vision + Discussion' started by DrD, Oct 7, 2014.

  1. DrD

    DrD

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    Many times, when the sun is brightly shining, it is very difficult to see the Phantoms tell-tale light sequences. However, when the Android Vision app has determined that enough satellites are stable, the sat count indication switches from grey to blue. That indication means that six or greater satellites are present, and ready to fly. BUT ... does that indication ALSO mean that a home point has been established??

    LED indication for home point established occurs before the indication that suitable satellite count "ready to fly gps" is present on the aircraft, but will the *Vision app* switch from grey to blue IF a home point has NOT been established, and 6 or more sats are in view? In other words, does home point and sat count (BOTH) have to be in place before the indication on Vision changes from grey to blue?

    My experience so far is that once the Vision indication changed, it WAS completely ready to fly gps, with a home point recorded. I don't remember seeing that in print anywhere, though.

    Cany anyone confirm this?

    Thanks,

    -Dale-
     
  2. job2310

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    If you switch to ground station mode in the app you should see an indicator where the bird is sat showing that the home position has been recorded. I often check this before lifting off just to give myself more confidence that we're ready to fly.

    PS. I also installed a NAZA-M LED on my bird to make it easier to see what the LEDs are telling me, check that out as a solution.
     
  3. mmn

    mmn

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    There's that little pointy radar thingy down in the left corner of the app. That thing centers when you have a home lock at your position.
     
  4. DrD

    DrD

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    Thanks, guys! Useful answers.
     
  5. AnselA

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    When Phantom has got 6 or more satellite signals ("fix") AND when the motors are started the home point is recorded.
     
  6. pb7424

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    I don't think the motors have to be started to record the Home Point. This is from DJI info:

    Home Point: When the Phantom enters ’Ready to Fly’ from the ‘Ready to Fly status (non-GPS)’, the GPS coordinates will be recorded and set as the home point.
     
  7. Damon

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    This is seen as a correct statement for P2 guys using IOSD mini. The act of CSC starting motors sets the distance as 0 in display. Not real sure if this correct on vision or vision+.
     
  8. job2310

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    I suggest don't start the motors UNTIL you have home lock.
     
  9. AnselA

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    It's easy to test. Wait for ’Ready to Fly’ (at location A) and then move Phantom e.g. 20 m (to location B), start motors, fly 20 m "away" from the launch position B and initiate RTH. Did it land on A or B? Which firmware version you have?

    DJI documentation is "famous" of inaccuracy...
     
  10. pb7424

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    When I fly my P2V+, I see two sets of rapidly blinking green lights at startup. The first set is when it gets enough satellites for GPS mode and then shortly after you get the second set which means home point is recorded. These lights occur before starting the motors. You can verify the home point is established by looking at the distance reading on the Vision app.
    I have the latest version software.
     
  11. rrmccabe

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    Actually my understanding of this is first set is course lock and second set is GPS usually. At least in Naza-M mode.

    They can also come so close together that you cant tell which makes me wonder if you can tell which one is which or if one always comes first.

    That said I know for a fact I got a rapid green flash a couple days ago and never had more than 4 sats which I verified with the LOG. So I do know that your first set of flashing greens does not mean you have enough satellites.
     
  12. Damon

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    This is true. I've done the same test several months ago. Had both sets of rapid greens. Moved P2 by hand to new location leaving p2 still on. Upon CSC the distance registered 0 indicating home position was where motors are started.
     
  13. pb7424

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    Thanks for straightening me out on this :)
     
  14. AnselA

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    Home point recording is not a function of Vision app.

    The TRUE verification is to test where RTH lands, it does not need Vision app at all.
     
  15. Damon

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    I tested this again tonight and found out my last test was not totally correct. Tonight I let p2 grab c/l and h/l then walked it about 30 feet and started engines. Iosd showed 0 so I thought it was based on CSC, but I tested again but walked it out 22 meters from initial power up and c/l & h/l and then started motors and it stated 22 meters in distance on iosd.

    It appears if the initial h/l and motor start is over a certain distance it reverted to the original h/l.

    I think my testing has now confused the issue more
     
  16. pb7424

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    Going through the manual again to get clarification, Page 27 under "Failsafe Operation" states: "After successfully record the home point, rear LED flight indicators blink fast green."
     
  17. rrmccabe

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    Why we are talking about this does anybody know but the distance has before you can reset home lock. As an example I'm pretty sure that you cannot reset homewok 500 feet away. I tried it once by mistake and then came to my senses on what can happen lol
     
  18. Damon

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    I'll test that out for you tomorrow if you really want to know.
     
  19. rrmccabe

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    That would be great. I had my head up my .... and was about 1000 feet away and got thinking I did not raise my homelock elevation which I would need.

    So I did the switch flip and then thought crap if its does RTH it will go way out there. I wasn't in danger and had control so I got up about 400' and did a RTH and it came back to me. I have not retested but led me to believe there is a point you cant reset the RTH Be good to know for those that fly off moving boats.
     
  20. Mako79

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    Need to be careful on the rapid green flashes.
    The phantom records 2 types, home lock and course direction lock. They will both rapidly flash green and one can occur before the other depending on GPS strength.

    To be clear, you can set new home positions anywhere. A reset of home position is indicated by the distance changing to 0.0. In Naza mode in mid flight - left toggle, flick from top to mid x 5 (its tricky with firmware 3.06) and you will notice the distance changing to 0.0 - this will be the new home lock/return to home/POI.

    If you flick from position mid to lower x 5, this will change the direction of the phantom for course lock. Which ever way its facing fwd will be the new forward direction in course lock.