Welcome to PhantomPilots.com

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

RTH Issue, Distance Issue, and more...

Discussion in 'Pro/Adv Discussion' started by mxx408, Aug 9, 2016.

  1. mxx408

    Joined:
    Jul 25, 2016
    Messages:
    19
    Likes Received:
    8
    Hello Everyone!

    So today I had three problems with my P3P at Baylands Park in Sunnyvale.

    1) Return to home did not function. I lost signal completely at about 1700 feet away. My P3P was supposed to come home to the successfully recorded home point after three seconds of being disconnected to the RC. However, I waited for like 3 minutes, and the drone just hovered in place ( I had just taken off a couple minutes earlier, so battery was not an issue). Then, it finally occurred to me to press the RTH button on the RC, and voila, it returned. However, I am still not sure why it did not come home initially. Also, how does the remote control send the RTH signal to the P3P if its not even connected?

    2) I am not getting enough distance. My P3P is getting choppy video signal at 1500 feet, and then a complete loss of both video and RC signal at 1700 feet. How can I be losing both connections at barely more than a quarter mile? Perhaps a range booster is in order? Its just so hard to believe I'm not getting anywhere NEAR the 3.1 mile transmission distance. Could that area of the bay have an extremely excessive amount of radio interference? Maybe my P3P is faulty? I hope not, as I soon want to start challenging for a spot on the distance chart.

    3) The DJI Go App is turning off my Samsung Galaxy s6. Whenever I turn off the DJI Go App, my phone turns off and restarts automatically, which is very annoying. I had to keep restarting the DJI Go App because I had a lot of trouble getting my RC to connect to my P3P (why, I don't know. It's never happened before today). I have an iPad Air 2 on the way, though, so hopefully it wont happen with that device.

    All in all, it was a pretty frustrating day at the park. It was real chilly for a summer's day, too.

    I look forward to and thank you for your replies!
     
    Pharm likes this.
  2. fastfed

    Joined:
    Jul 5, 2016
    Messages:
    544
    Likes Received:
    161
    My best guess's, RTH is done through the aircraft, its stored in the aircraft, you should be able to turn off the controller and if no connection is made at a period of time, the craft itself will initiate the RTH, but, if you are connected even for a split second my experience it will not RTH, each reconnect resets the time.
    Next time, go out 500 feet or so, decent altitude over bare land and turn off the remote, the drone should RTH.

    I looked up the baylands park, did you fly over that bay? the water area? its extremely congested from what google maps show, make sure you bring altitude up a little for each time you drop signal, a bar goes down, craft goes up, it's what I do.
    If you're looking for that challenge, then yes you will need to invest into a nice panel and go boosted, then find the most deserted area with flat ground and no to little interference. These distant records you will see all the flight paths, its over the sticks lol.

    As for your GS6, I've learned the hard way, make sure when you plug in the phone, you select midi device as the usb type, not transferring files. and make sure the phone holder isn't pressing up against the power/volume buttons :)
     
  3. FantomFlier

    Joined:
    Mar 21, 2016
    Messages:
    230
    Likes Received:
    76
    What options have you set for RTH? Ensure that it is indeed return to home, and not 'hover'.
     
  4. Flipsonic

    Joined:
    Jun 8, 2016
    Messages:
    321
    Likes Received:
    74
    Location:
    San Francisco Bay Area
    1) Do you have RTH set on RC signal loss? You'll find that in advanced settings. You might have it currently set to hover. The RC does not tell the AC to come home on signal loss. The AC will automatically do what it is programmed to do during signal loss.
    2) Do you have the latest FW on the AC and RC? That may be causing the short range. I have a P3P and can go over 2 miles on flat surface with windsurfers on. Haven't tried to push it beyond that. I'm sure it would go farther. Key is, you have to have good LOS.
    3) Not sure why your phone keeps resetting. Maybe reinstall DJI GO will fix it. When you get your iPad Air 2 you should be golden. I have it and never failed me with either DJI GO or Litchi.

    Btw I live in the East Bay so looks that you are not so far from me.
     
  5. Vertigo

    Joined:
    Jun 12, 2016
    Messages:
    499
    Likes Received:
    148
    Since the RTH button worked, you did not lose control signal, you only lost video. The phantom will not RTH automatically as long as you have control (except when battery is low and you have smart RTH or whatever its called enabled).

    So many factors influence range, the most important ones being the environment (lots of wifi's or cell towers,..?), your altitude (higher means better range), antenna orientation, .. and not to forget, if you have the EU version, you will not get the range you see from the US version, as the transmit power is lower.

    Thats weird, thats all I can say :/
     
    cfd701 and Oso like this.
  6. Mark The Droner

    Joined:
    Aug 26, 2015
    Messages:
    3,960
    Likes Received:
    1,156
    Location:
    Brookeville, MD, USA
    Your first and second problem are the same problem. When you "lost signal completely", you didn't really lose signal completely, you only thought you did because your telemetry disconnected so your app was reporting the last info it had - which was old info and bad info. The truth is, the control signal was still reaching the aircraft. It had either disconnected and reconnected, or was becoming intermittent.

    One thing to think about when at your range limit is polarity. If you're moving full throttle, the aircraft will tilt and the polarity may not be perfectly aligned (or the wavelength may be compromised), but when you lose signal, the aircraft hovers and returns to perfect horizontal (and antennas return to perfect vertical), and then it may suddenly find itself perfectly aligned which allows the signal to reconnect.
     
  7. Ken0392

    Joined:
    Aug 9, 2016
    Messages:
    4
    Likes Received:
    1
    I had something similar happen to me, it is a scary moment. I hope you figure it out. I had a Phantom Standard and when this happened to me lost signal,video and when trying to RTH it gave a little message on my screen saying "RTH FAILED" I was only in the area of 1000 feet in distance from home point and my altitude was like 300 feet.. Somehow I managed to regain some signal and flew her back and the first thing the next morning I took her back to Best Buy and upgraded to the P3P and all I can say is...... WOW what a great decision on the upgrade on my end... Hope it works out for you... Mine was a hardware issue
     
  8. sonof40

    Joined:
    Oct 22, 2015
    Messages:
    515
    Likes Received:
    82
    Location:
    San Ramon, CA
    mmx408 and Flipsonic, we should get together sometime. I'm in East Bay too. (San Ramon)
     
  9. Oso

    Oso

    Joined:
    May 19, 2015
    Messages:
    2,521
    Likes Received:
    1,474
    Location:
    Sacramento CA
    As @Vertigo noted, you likely did not lose control signal which is almost certainly why RTH did not self initiate. I say that because we see this exact question asked many times, so chances are it's the same in your case.

    The FPV (video) signal and the control signal are separate from each other. Full control is still possible (within range) even if you've completely lost your video signal. You can in fact turn off your mobile device and still have a strong control signal. This concept is very commonly misunderstood with newer pilots. I think it's because the messages in the app are confusing at first.

    What we have noted here on the forum many times is to check the far left LED on the RC. If it is green, you still have control even if you have no FPV or even if you have no mobile device at all. Your AC will be sitting out there somewhere waiting for you. It has no reason to RTH. If the LED is red however, you've lost your control signal and the AC should then self initiate a RTH based on the settings you have programmed in advance. I hope that makes sense!

    Good luck sir!
     
    #9 Oso, Aug 9, 2016
    Last edited: Aug 9, 2016
    matti, m0j0 and sonof40 like this.
  10. Oso

    Oso

    Joined:
    May 19, 2015
    Messages:
    2,521
    Likes Received:
    1,474
    Location:
    Sacramento CA
    I was just in San Ramon last Saturday. I used to live there just off of Alcosta Blvd. It's a very nice city, even if nearby Dublin has become a sprawling metropolis. Cheers sir!
     
    sonof40 likes this.
  11. Flipsonic

    Joined:
    Jun 8, 2016
    Messages:
    321
    Likes Received:
    74
    Location:
    San Francisco Bay Area
    I work at Bishop Ranch 15 in SR and live in Antioch. Sounds like a "meet"...one day.
     
  12. Dronason

    Joined:
    Aug 9, 2015
    Messages:
    498
    Likes Received:
    82
    Location:
    Switzerland
    There is not 2 types of P3 / remote control. It is the location of the drone that define the transmittal power. See last post CE or FCC Phantom 3 advanced
     
  13. m0j0

    Joined:
    Dec 26, 2015
    Messages:
    1,532
    Likes Received:
    529
    It did not return home because you had control. As stated earlier the video signal and transmitter signal are not the same. You know you have lost all control of the bird when the light on the TX goes from green to red.

    Don't take this as an insult but do you have the antennas oriented properly? The tips should be pointing up with the flat side of the ant aimed at the bird. The further away you get the more important it is to properly aim the TX signal.
     
  14. Vertigo

    Joined:
    Jun 12, 2016
    Messages:
    499
    Likes Received:
    148
    Is that so? The control link is bidirectional, you send flight instructions and you receive telemetry data. Note this is not FPV video data, lets completely ignore FPV here which is a separate signal. Among this telemetry data is the control link strength as seen by the Phantom, which is the only way to know if and how well it is receiving you. If the phantom cant "hear" your controller anymore, it will still send telemetry data back that includes this loss of signal. So as long as your controller can still receive that, it would know where the phantom is, how high/fast etc, but it would also know the phantom is not hearing you and correctly state a loss of control. Your LED would go red. In this case, which is the usual case, you can track the phantom's location etc for as long as the telemetry link works, but you cant control it and the Phantom will automatically RTH, until the control link is reestablished.

    But the other way is also possible; if your controller is no longer receiving any telemetry data (including signal strength data) from the phantom, it wont know where it is, but it also wont know for sure if the Phantom is still receiving or not. It will have to assume its no longer the case, your LED will go red, but it doesnt necessarily mean the phantom is no longer hearing your control signals. You just have no way of knowing it (except if you can see the phantom LEDs which I believe will show this) because you lost the RSSI telemetry data. Usually this will happen only after the Phantom stops hearing your control signal, see below, but it doesnt have to be like that. IOW, the app or controller LED might give you the false impression the Phantom lost the control signal, when in reality, you only lost telemetry.

    The interesting question now is, when does the Phantom RTH, when it loses the control signal (red led), or also when only the controller loses the telemetry signal (red led)? Theoretically, the controller could also send its telemetry signal strength back to the phantom, so the phantom might know when you lose the telemetry link (and you receive a 'signal lost' message and red LED), even if it still hears you and so you still have control; it could ignore your control commands and initiate RTH when that happens, but this would make little sense and if the OP indeed had a 'signal lost' indication, this strongly suggests this is not the case. A signal lost indication should therefore be interpreted as a telemetry lost indication, and while it may be rare, you may still have control at that point, and thus the Phantom may not RTH by itself unless you tell it to (or turn off your radio, so the Phantom no longer receives the control signal).

    BTW, on my taranis radio I have 2 signal strength indicators for this precise reason. One for telemetry (from the plane to my radio), one for control (the signal strength my plane's receiver measures, and relays back via telemetry). The telemetry link tends to be a bit a stronger for a variety of reasons (lower bandwidth link, transmitter, which really is the receiver, further removed from ground etc), so a loss of telemetry usually means trouble and tends to happen after losing control, but it is possible to lose telemetry without losing control. And then there is no way for my radio to know it still has control. This is especially true if you have a local source of interference near your radio, which will hamper its reception (telemetry), but have no impact on its transmission and be too far to have any influence on the receiver in your plane.
     
    #14 Vertigo, Aug 10, 2016
    Last edited: Aug 10, 2016
  15. Meta4

    Meta4 Moderator
    Staff Member

    Joined:
    Jan 8, 2014
    Messages:
    7,714
    Likes Received:
    3,436
    The manual is pretty clear ... 3 seconds after losing the control signal.
    [​IMG]
     
  16. Vertigo

    Joined:
    Jun 12, 2016
    Messages:
    499
    Likes Received:
    148
    The manual doesnt differentiate between the telemetry downlink or the control uplink, neither does the single RSSI indicator on the app or the controller LED. So no, the manual is clear as mud in this regard. Reread my post carefully.
     
  17. Meta4

    Meta4 Moderator
    Staff Member

    Joined:
    Jan 8, 2014
    Messages:
    7,714
    Likes Received:
    3,436
    I can't see any ambiguity in the words if the remote controller signal is lost.
    It seems perfectly clear.
     
  18. Vertigo

    Joined:
    Jun 12, 2016
    Messages:
    499
    Likes Received:
    148
    Then tell me what happens when the phantom receives your control signal but you dont receive telemetry from the phantom?
     
  19. Meta4

    Meta4 Moderator
    Staff Member

    Joined:
    Jan 8, 2014
    Messages:
    7,714
    Likes Received:
    3,436
    You seemed to know in post #5 above.
     
  20. Vertigo

    Joined:
    Jun 12, 2016
    Messages:
    499
    Likes Received:
    148
    I actually deduced from post #1 what happens. Its obvious the controller will indicate a loss of signal, since it cant know anything else. Its far from obvious what the phantom would do in this scenario and I dont see it anywhere in the manual. Or did I miss somewhere where they explain a "control link lost" indication may in some cases actually mean the control link isnt lost and it wont initiate RTH by itself?
     
    #20 Vertigo, Aug 10, 2016
    Last edited: Aug 10, 2016