Biggest culprit of ~~interference~~

So I just had 2 wrecks in a row from what could only be described and cronic interference... one messed up an APM board and damaged other parts. It is ok, but I think it happened when the failsafe kicked in on a low throttle input... anyway I had spare parts so things back together. The problem is the GPS or the board is getting tons on interference from something. When I tried to put it into Loiter mode it looked like it was a shooting star. Luckily I flipped it back in time. I have not run compass mot as of yet.

This is the sixth Arducopter rid I have setup from scratch. It flies beautifully in stabalize but anything else it goes crazy.

Anyway, I am not running anything all that different than my other quad, infact, the GPS is the same one   (6M ublox). It works fine and dandy in the mission planner.

Anyway, it seems that ever since I put the Power Module  -or- the telementry things have started going batty.

I installed a FPV setup nearby the APM (a 600mW immersionRc, hooked to telemetry, hooked to a 3 channel video switcher), but removed it for the test which resulted in the second wreck. I *thought* it was the video stuff but now I am stumped.

I added some pics of this rig, what I am wondering is what is Biggest culprit of ~~interference~~ and what is the best way to deal with it, eg. Video transmission, GPS, AMP etc..?

Thanks in advance!

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • One of the sometimes forgotten interfering signals into a GPS is the RC telemetry capable receives used by many pilots now. FrSky, JR or Hitec telemetry etc. The RX antennas are also transmitting, but this is easily forgotten. I found I could not fit the receiver whisker antennas within 100mm of the GPS on my copter or the number of satellites locked dropped to one or two. Although these are on 2.4Ghz and should be out-of-band, the RF power at close range can swamp the sensitive front end of the GPS receiver desensitising it regardless.

    I hang the RX antennas below the main frame now rather than having them above or level with the APM and GPS.

    Might help.



  • Hi Mark, +1 for RX/TX problems. I went through a few crashes recently with loiter issues and also failsafe activating for unknown reason and did the following

    1. I upgraded my NEO 6M with the latest settings for 3DR. see this helped with quicker GPS locking and some more stability 

    2.Reduced Loiter PID (GPS glitches can cause sudden and aggressive position changes while in loiter mode.  You may wish to reduce the Loiter PID P to 0.5 (from 1.0) to reduce aggressiveness. this helped that I could catch the copter if loiter went stupid

    3.Replaced my Turnigy 9XV2 TX/RX with the FRSKY system and have not crashed since. however I do manually check loiter a few times before I fly.

    Good luck hope this helps a little bit.

  • Here is the Log:

    I am not to savvy with the log stuff and I need to read up on it. Shyam, got a tutorial on this one yet?

    Now on to another problem as I bought this cheap gps from It uses of old port on the APM (the gps port on the side) and it never seems to get a lock. Even after an hour of having it outside. Man, this is just a huge bummer.

    Those are the logs. The one on the 16th is the day is just dropped out of the sky like I have never seen. My girlfriend has it on video I think. Will upload.

    2013-11-18 23-48 2.log

    2013-11-16 18-51 168.log

  • Ah sorry about that. Here are the pics.


    I am thinking that the USB cable (I use this to plug into and program the APM... Maybe I should be using the wireless but wouldnt that create even more interference?

    3692883137?profile=originalI did find what seems to be a bigger problem. The faithful Ublox 6M watch sized battery just broke off. Perhaps that is the problem here.  I should mention that this is an attempt to copy an exact setup I have already running with a gimbal (not yet on this setup). In fact when I had the flyaway it was just the with this simple APM + receiver and gps. The cam was no on. Notice that little mini usb cable to make it more conveinient to plug stuff in. I know this aint the prettiest setup, but I go 'function of fashion' every time and this simple crash helmet consisting of the top of a plastic juice bottle saved works like a champ.  

  • Boy does this sound familiar. I posted the same issues about a week ago. Using the same hardware I have used successfully for about 8 months - APM 2.5, Ublox gps, 3DR telemetry and sonar. 3 crashes since updating to 3+ firmware, last one destroyed my quad. I have since rebuilt on a HK frame and it flies GREAT in stab, but switch to loiter and it looks like a missle climbing. I thought I might have a bad GPS connection, but have not been able to verify. I have replaced my GPS and disabled my sonar. I think I will also disable the telemetry module. This will get it down to the most basic essentials. If it still behave the same I'm going to start questioning software.

    If you look you will find a number of similar posts in the past couple of months.

    Hope we find a solution.


  • Bet you that it is the telemetry unit, had the same problems 

    You need to make sue that the GPS and the telemetry modules are separated by as far as possible

    Good Luck 

  • Moderator


    First, sorry to hear you're having so much trouble. Second you mentioned you added pictures of your setup? I don't see any pictures...

    Since you have telemetry, can you post a tlog from a flight where it's acting like a "Shooting Star"?


    Nathaniel ~KD2DEY

This reply was deleted.