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R/C signal lost mid flight (no error on screen)

Discussion in 'Phantom 2 Vision + Discussion' started by justin00, Oct 12, 2014.

  1. justin00

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    so was flying today at the nornal park.. no power lines or anything that could cause interferance..
    flew 20 minutes till battery #1 was empty, then let it cool down for 15 minutes then put the second battery in..

    10 minutes into the flight it was about 25 metres away horizontally with altitude of about 150ft and sudden I lost all controls.. couldn't move or do anything.. It was in GPS (naza) mode with 11 satellites lock on, home position locked in... The FPV/tele data was still working.. There was no error on the screen indicating R/C lost. Then it started flying away pretty slowly from me INTO the wind (not a strong window) and I changed to ATTI mode and nothing changed, didn't even flash yellow (to signify a diff mode), changed back to GPS anyways...maybe 10 seconds after that it said "coming home" and worked brilliantly in that regard..I hand landed it as soon as it within reach.

    Anyways some info.. had it about 3-4 weeks.. maybe 25-30 flights... 3 weeks ago I did the aluminum tape GPS shielding mod which fixed that up nicely.
    About 10 days ago I installed a flat panel 11dbi 5.8ghz antenna for the R/C controller and correct pigtail. Had heaps of flights since that was installed and all working perfectly.
    Now I no the flat panel antenna's are direction and I have the panel, with the flat panel part pointing up the air, also at close-farish range it actually seems to work at 360 degree's, so they aren't completly directional..but anyways as this happened it was pointing at the Phamton.. but yeah at this close range I could of had my back to it and it would of been fine but anyways.. The only thing I have done recently is.. on the Camera and range extender I put this in /etc/init.d/networking so it sets the txpower to 17dbm "iw phy phy0 set txpower fixed 1700" but this is for the 2.4ghz FPV network.. Its just the only thing I've done differently so thought I would mention. BTW though... I have been using the app to boost the range to 17dbm for past 2-3 weeks anyways.. it is just last night I added the commands manually so I would not need to load up the app anymore (except when I use data logging... which I stupidly didn't have turned on for this flight as I was not doing anything except.. just laps round the park)

    Also as I said I was able to use a full battery and half of the second battery before this happened. Oh yeah I put in new (good brand, non rechargable) batteries in the R/C about a week ago.. however no sign of no battery power issues.

    Oh yeah once I grabbed it the engines shut off straight away and like I said there was 9-10 minutes left.. the control inputs were still not working.. I couldn't move the camera left/right.
    When I got home I turned the Phantom, RC and extender back on and all is working perfectly again.

    I semi-violently shook the R/C controller to confirm the pigtail or something did not come loose (I hot-glued the UFL connector on anyways when I installed) and everything was working fine after the shake..

    If I didn't have 6+ satellite there is no doubt it would of flew off into the distance.... Now i'm not saying this is a fly away, cause it wasn't.. The phantom did what it was supposed to when this happens I guess..

    Some questions I have though :)

    1. if it was R/C signal lost issue, why did it not report it on the screen as I have seen it do before when I do fly waay out of range ? As I said this was close by.
    2. What else can I check / do ??
    I did not do a compass calib before flying today as I always fly at this park.. 90% of my flights have been at this park so I don't redo compass often, and it did lock on to GPS and fly back to home position perfectly.
    3. How do I get over this mentally lol.... Like How am I going to trust this thing now ??
    4. I could call up the hobby shop I got it from but they would say "bring it in" and they would test it and see it is working perfectly....

    On rare occasion I have flown with 4-5 sats but never going higher than 50ft because I was to scared... but this just confirms it, and confirms what everyone here... DO NOT FLY WITH LESS THAN 6+ SATS... Even 6-7 might be asking for trouble if it is cycling between 5,6,7 etc etc.. Luckily I had a firm 11.

    Also luckily home point was in the middle of the park anyway from any tree's, but also just confirms home point needs to be like this...

    I know I could of shut off the R/C controller.. I was actually to scared to do this initially, I would of eventually; however the failsafe initiated by its self luckily...
    To be honest it seems to me like as far as the Phantom was concerned.. the R/C controller was off...

    Thanks... still pretty freaked out and pissed off this occured..... Kinda funny I was saying in a thread yesterday to some one worried about this... 'ah stuff happens'

    :(

    Hoping to hear some recommendations and miracle cures :) ?
     
  2. justin00

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    Reading through people fly-away and near fly away stories... everything seems pretty similar... in most cases there does not seem to be R/C lost error message pop up... you seem to just lose connectivity...

    Kinda devastated.. loved going to the park to fly.. and $1800 kinda alot of money to pay... You guys all know that as you paid similar amounts I'm sure in your own currencies.

    I could call up the place I got it from and demand an RMA... but how do I know it won't happen to the next one... It is not like was a bad batch of these produced...

    And yeah I am being a lil dramatic, it didn't fly away.. it did what it was supposed to do.... minus the hole losing R/C connection thing.

    If it was interference I just don't understand how it has never happened there before... and its the middle of a park...

    :(
     
  3. singapore_phantom

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    As it happens, I encountered similar aberrant behavior a while ago. Was flying at my regular spot, 12 sats, plenty battery power, all-clear. Suddenly, at just under 100 m, the first time I had ever reached that altitude, my GS cell display said "Signal Lost". Simultaneously, I noticed that my TX controls were being ignored by my Phantom. The loss of control lasted all of 2 seconds, but it freaked me out, because it was unexpected and inexplicable. You're right, it undermines your confidence a little, but at the same time, it's not big enough of an issue to be able to conclude anything, let alone do anything.

    Needless to say, I packed everything in that day and did a thorough test on the entire copter back home to see if anything wasn't quite right. Couldn't find anything untoward. I also replaced my (still full) TX batteries with brand news one just to be sure.

    Anyway, long story short, it happened again a few days later. This time at barely a few meters altitude. Again it lasted a few seconds. And this time, I was in the video and you can see that I'm pressing the right stick right hard. But the copter remained stationary. It then snapped out of it. But i took it home all the same.

    That was a few days ago. Since then, I flew a few sorties, all without incident.

    I'm still double-checking everything before going of on sorties now. Better safe than sorry eh.
     
  4. justin00

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    Yours actually said rc lost thought qhoch was diff to mine

    Running any of the same 'mods' as me at all? Booster app (doubt its this..but who knows.. perhaps something overheating)? Panel antenna?


    Have there been cases of it literally flying away with full sats and not returning to home? (or attempting to..maybe ran out of battery on the way)

    Mine scares me as it didnt say rc lost... but thinking back I guess it could of said it quickly and maybe I missed it..was focused on Phantom.

    I work for a large Telco... so tomorrow I'm going to a) ask the experts what can interfer with 5.8ghz and b) find out exactly where the cell towers are or any other telco equipment... If I recall correctly some commercial microwave??/wireless data comms runs on 5.8ghz..

    Might also go back to park tonight... im happy my shake test has proven the phantom ,controller and antenna have nothing loose... best way to get over fear is get back on the saddle... but ya wont do anything long/crazy...not that i ever do fir fear of this happening... :/
     
  5. flyNfrank

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    I have only seen this from those that have modified their controller for a aftermarket antenna. Anyone that has modified their controller knows after scraping white glue there could be connections issues at some point.
     
  6. timtown

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    Although I'm not an comm expert, if one looks at to whom the FCC has licensed 5.9Ghz, it would appear that the U.S. Government is the largest user, suggesting possible momentary interference. Unfortunately, frequencies in the band used by DJI are becoming more popular. Now then, the 3.06 firmware attempts to understand bogus communications over ~10sec of time. Then if requirements are met, it will implement RTH as a safeguard if you have activated Receiver Advanced Protection Function in the Assistant software. I'm a bit hazy over the 10sec time span as I've heard 20sec as well. Had DJI used digital communications, they could use a protocol to discern between interference and legitimate TX comm and avoid this vulnerability .

    For those interested, there is a spectrum analyzer on the market that will give you a picture of what is going on in the field. Reference: http://files.metageek.net/marketing/Wi- ... medium.pdf . A comm specialist sent this to me; I sense it is low cost.
     
  7. justin00

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    I was 10000% careful wen removing glue.. like a surgeon :p
    Or do you mean the glue was acting as a shielding. When i put new ufl connector on it clicked in nicely and I did have heaps of sucessfull flifhts nefore this. Also my shake test im hoping confirms nothing is loose? Put hot glue over ufl aswell.


    Speaking of FCC... im in Australia so should be om CE but use FCC due to range... can this cause a problem.. agsin had heaps of flights in exact same spot with FCC and new antenna.

    i also opened up the panel antenna and confirmed nothing lose. Ita just 2 copper looking plates anyways with bit of wire in the middle.

    called up hobby shop and they said just recsli compass.. but hmm..ill certainly try that but dunno if cause.
    anyways gonna ask my telco buddies at work what can interfer with 5m8ghz range.

    Thanks :)