When the nose of my quad points south,  the Planner (or copertGCS) say North.  - all directions are good, but wrong.

The APM2 is mounted so that the SD card is in front left corner. - and GPS up, of course, do please don't ask that :)

it flies well, - but needless to say is useless to position hold, RTH.

how is this even possible ? - I recalibrated Compass, and also flew with learning on - does not help - the directions are good, but rotated 180degrees.

Firmware 2.5.4.

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Sounds like a defective compass. I'd contact the store customer service for a RMA: help@3drobotics.com

ok, calibrations are very random, after doing several calibrations, I hit one that is pretty useful, will try to use learning to fine tune it.

And now I lost it at sea ! (with a 3DR frame and Bluetooth adapter)

Yep, after a few minutes or reliable hovering, and position hold , it started to drift away, living on an island, it did not took very long time to get well over water. after a while, It increased forward pitch to a point where I were unable to level it off by holding max "back" on the stick, PH and RTL also failed to level it, and it hit the water some 100 meters from shore.

I do not know what went wrong, or why it happened, because that was way out of BT range.

Complete loss, 3DR, new APM2 , BT module battery ETC is on the bottom of the sea. - wish I could learn something from it.

Andke: very sorry to hear that! We're you able to get logs from at least the beginning of the flight when it started to drift away?

Hi, this - in "quadcopter" folder is unfortunately all I have, did not had chance to look at it, or see if Quadcopter logged more, see attachment


now I checked the files, they are useless. no tlog data. does not seem like "Copter GCS" is recording it.

Andre, sorry to hear about the loss of your quad!
I had a similar experience yesterday that concerns me. I am still in the setup phase (newbie) and my plane (using Ardu plane) was pointing south but the planner was showing north. Exactly the same scenario you described. I powered of and went back to the manual to confirm correct installation. When I powered it back up it was correct again. Very strange. Maybe some of the APM gurus have some thoughts on this issue?

We think there's a startup bug with the mag on APM 2, which we're tracking down now. If you press the reset button after you plug in your battery each time, it should be fine. We'll push a fix with the next code rev.

oh cr@p - I just realised  what must have gone wrong by looking at my last config file, + rethinking the events.

My config file is nothing much to speak of, default values on everything, as it was a standard 3DR frame.

I have long experience with autpilots, both MK, OpenPilot, RVOSD and APM1 (and now - catastrophic experience with APM2)

Important info 1:  I've seen on earlier flights that "idle" position of roll/pitch stick (mode2) could "move" - and require bigger input if I flew manually and held pitch/roll over time to fight wind - no I did not use autolearn, but leveled the 3DR properly before.

Important Info2 : I "recalibrated" crazy number of times, and "by luck" struck "north-south-east-west" that was good.  - most calibrations were mostly random - only APM2 USB powered, no other magnetic fields/power nearby by battery power (carefully verified that).

Then - most likely my doom - I enabled Compass_Autolearn


>3 minutes into flight:

I took off and it held position nice, I tested RTL and PH.  and it somewhat circled

- I went back to Stabilized control, and held it in place with a little climb while fiddeling with my Galaxy note (CopterGCS) to see that was going on(telemetry) (checked AHI screen and gyro/accelerometer curves, did not see anything crazy) while doing so, I held it in place using right stick (mode2) contantly applying input to counter wind.

after ~20sec: I switched back to PH - the 3DR took off directly away from me ! (just like before - with inverted compass)

I switched to RTL, and back, it kept flying away from me at good speed. I hoped for it to circle (bad compass) or stop. Maybe 6-8sec leter,  200 meters away I switched to stabilized.  

Now it did not want to level off !! (I could still see its orientation because of powerful LED's.)

I tried to apply full input in the opposite direction. - no luck.

I yaw'ed it's pitched side back to home, to get it back over land, (knowing that would obscure the sight of LED strips.)

By now my maximum stick input was not enough to counter it's will to roll/, I lost altitude too fast. The last meters above water, I released stick and applied full throttle. in some soft of hope that it would level off and climb - nope - at "full speed" - more forward than climb, it hit water.

So this is a combination of two disastrous errors.

-Bad compass, that moved it far away instead of "home" or "hold"

-some bizzare error that makes the APM2 translate it's attitude - or stick input differently after a while of a constant stick input. (like when you fight wind while hovering in stabilise mode)

3DR, brand new APM2, BT module, battery , Li-Po low-voltage beeper, and Graupner GR16 receiever. R.I.P.

Wish a had a good video of the splash.

great - I hope that it's rusted remains will wash up on shore after storm in the fall, then I'll post a picture of me pushing reset  :)

"you bastards - you killed Kenny !"  (is it too later to name it that ?)

Andke, two days ago my quad with apm2, 2.5.4 software ver flight away. After take off I switched to PH and wait a few minutes. The wind about 10-15 km/h. Returning to stabilize the quad was not horizontal but I could comeback. After landing take off again the trim was correct.

Again switched to PH and moved the stick to fly. After one or two minutes I could not return to horizontal position and switch on RTL. The quad didn't comeback still being tilted about 45 degrees. Again switch to stabilize but run out of the swing bar. Finally the quad flight away with remaining run time of battery above 20 mins. Pity it was fully carbon without any compromises.

For sure compass direction was correct and well calibrated. Unfortunately on that day I removed xbee and minim osd and have no any record and to find the quad is slightly impossible. Within this weekend I will try the second quad but 2.5.5 ver.

It seems that we have the same symptoms excluding problem with compass direction.

@Jacekheli: Very sorry to hear that. We did try to alert everyone to upgrade to 2.5.5 (which resolves the issue with the accel scaling in some boards, which may have been what you encountered), but perhaps you missed the announcement at the time. If you PM me, I can arrange for you to get a replacement APM 2 board at a developer's discount. 

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