When I try and fly with GPS mode it starts to fly off, out of control. It seems to fly normally in ATTI mode. I have calibrated the compass several times and have linked up with the software and saw no problems. I opened the unit and didn't see any damage to the GPS unit. I have crashed several times though! Anyone have any ideas, Thanks.

I would perform an advanced IMU cal.  If it gives you a message it is too hot, click okay and let it go.  Make sure it is level and not near metal. It is done when you see a green check mark.

nrgwise Posted at 2015-4-8 09:58
I would perform an advanced IMU cal.  If it gives you a message it is too hot, click okay and let it ...

I have tried that but I will try it again, thanks.

Calibrate the compassandmakesure youve given the Phantom plenty of time to fix firmly onto GPS. Is the LED indicator flashing only green?

Right - go outside where there is clear vision to the sky.

Turn the TX on first. Both switches in the UP position.
The connect the battery. Stand a few feet behind the phantom and let it sit for at least 30 seconds and perhaps a full minute - at some point it should do a bunch of flashing greens and then, after that, flash green slower. This means it has a GPS lock and is in GPS mode.

http://www.droneflyers.com/talk/ ... the-first-time.473/

droneflyers.com Posted at 2015-4-13 10:47
Right - go outside where there is clear vision to the sky.

Turn the TX on first. Both switches in t ...

I do that every time. If I am hovering steady in ATTI mode and switch to GPS mode it starts to moving around and fly off.

Something is wrong then......if the unit is under warranty you should send it back - if it's not under warranty you may want to take it apart and inspect all the connections to the GPS unit, etc.

If the IMU reports as being proper and the compass is calibrated - and if it flies normally in ATTI, then it probably needs professional service.

droneflyers.com Posted at 2015-4-15 05:11
Something is wrong then......if the unit is under warranty you should send it back - if it's not und ...

Thanks for the info. It's out of warranty for sure buy now.

I guess the next steps may be to decide:

1. Send it into one of the independent drone repair shops...
or
2. Look around for a new GPS unit for the bird and install it - you may be able to get a used one on eBay or from one of the drone repair places..
or
3. Part it out or sell on eBay with proper description of what ails it.

This could be a compass issue.  If it flies well in Attitude mode then the main controller unit with accelerometers and gyros is working OK.
If you are getting the indication that you have a GPS lock the GPS is probably working OK.  But if the compass is mounted wrong after a crash and leg replacement or if it has been affected by a magnetic field the GPS mode will not work properly

I've got a few suggestions based on my experience.

1) Look up the manual info on compass / IMU calibration and write down the acceptable value ranges for each section.

2) Look at the live output of the compass / IMU values and make sure they are within spec. NEXT, move and rotate the multirotor and check to make sure you see movement on all axis. Sometimes a particular axis will get "stuck" and not update. If that happens, common internet wisdom recommends giving the GPS puck a good firm tap to unstick the offending axis.

3) Recalibrate the compass and IMU four or five times in a row - do this way out in an open field without your phone or camera on. I've had this work a few times.

4) If none of these things work, or if the live Compass / IMU numbers are outside of the acceptable range despite multiple recalibrations and being in the right location, you may want to try degaussing your gps. Do a Google search and you should find it. I found that out after transporting my quad near my rear passenger-side car speaker.

Good luck!

you said you opened the phantom up did you use a magnetic screwdriver or get a magnet near the compass at all like launch off the back of your car were it was near the rear speakers if so take a magnet and circle the compass then recalibrate it....Good luck

As a newbie with a 1.1.1 I'm just wondering how you handled this?   Did you intitially take off in ATTI mode, try switching to GPS mode, then quickly back to ATTI to regain control?

Cessna172 Posted at 2015-7-14 02:00
As a newbie with a 1.1.1 I'm just wondering how you handled this?   Did you intitially take off in A ...

That is a method I have seen other pilots use.