As I understand it RTH only works when the aircraft is more than 20m from its take off point..  

This leads me to ponder the following...

If I take off from a river bank and fly over the water but am still within the 20m what happens if I lose connection? Does auto-RTH still work or will the aircraft descend into the water?

I realise a lost connection this close is unlikely, but it seems it's not unheard of.

I guess the simple questions are:
- Does auto-RTH work when closer than 20m from take off point?
- If I fly more than 20m and return to a point less than 20m away from take off point, will RTH (auto or manual) work?

I know I could probably test these somewhere safe, but I've been scouring a couple of places I'd like to fly and it just got me wondering.

Even a few metres from the riverbank into the river would be a problem for retrieval and I really don't fancy getting wet especially at this time if year.

(I've actually got some safe area flying planned first, so I might experiment a bit, but it would be good to know what more experienced pilots have seen happen.

+N.O.T.

I think youre correct, it would hover where it lost connection, I'm not 100% sure, i think it may back track some feet 1st though to try to reconnect before it will RTH or hover in place

HI,

Good question!

Failsafe RTH is different than an user initiated RTH.

Failsafe ; craft will fly backwards 50 meter on its original route, than a straightline RTH.
Manual selecting RTH, close to HP is not possible ; on the screen you get a message, only landing with your confirmation is possible.
Best to to test this out over a large free area, get to know this behaviour in all situations.

cheers
JJB

I guess the safest thing would be to always take off at least 20m from the water's edge.

In case that's not possible I think I'm going to do a bit 9f experimenting where it will be fine for the drone to force land itself without me having to go for a swim. (If you've seen my YouTube channel you'll know that I've tried sub-zero swimming, but I was properly prepared for that - chasing a drone into a winter river doesn't have the same appeal as ice diving a mountain lake!).

-N.O.T.

Test it over safe dry land. The manual is rather confusing, testing leave no ambiguity.

BWJ Posted at 12-10 13:24
https://www.youtube.com/watch?v=N3YrsmEdo3E&ab_channel=IdahoQuadcopter

Thanks,

I watched that a few weeks before finally buying my Mini 2 and it's a very informative video. I might give it another watch but I don't remember it going into a lot of detail regarding the 20m minimum.

I'd hate to be stood on a river bank watching my drone slowly descend into a cold, watery death - maybe I need to get myself a long butterfly net

My son experienced exactly this when flying over the sea. He’d launched close to the shore. Something happened and the drone descended slowly into the sea and sank. He was traumatised. Now he’s sure to launch well back from the water’s edge.

Amazing what one can find in the manual -

Mobilehomer Posted at 12-10 17:44
Amazing what one can find in the manual -

[view_image]

That doesn't quite answer my question, though, does it?

Situation:
- I launch from a riVerbank. My RTH point is only a couple of metres from the water's edge because the river path is the only level area from which to launch, and there are trees further from the oath 0reventing a hand launch.
- I am flying happily backwards and forwards along the river getting some nice video and photos.
- I am not flying much more than 50m in either direction along the river, and the river is about 10 metres wide.
- For some reason I lose connection with the aircraft. The aircraft at this point is about 10 metres from me, in the middle of the river.

What happens? I don't think the manual is clear on that.

Does the aircraft retrace the last 50m of it's flight path up and down the river attempting to regain signal? If so that would mean it flies further away from the controller...

If signal is not regained the aircraft will still likely be less than 20m from the home point (continues...)

No Original Thought Posted at 12-11 04:53
That doesn't quite answer my question, though, does it?

Situation:

(...continues) as I have not been flying very far.

As I am closer than 20m, does the aircraft initiate an emergency RTH? Again the manual is not clear - particularly that mention of the 20m limit again.

And if the RTH is off target a bit, I'm going to be stuck as I launched probably a bit too close to the water's edge.

All hypothetical, I'll be aiming to launch further from the edge, but knowing the behaviour of the drone beforehand would be useful.

Unfortunately it's not good flying weather this weekend so I can't go out and experiment on terra firma.

-N.O.T.

No Original Thought Posted at 12-11 04:57
(...continues) as I have not been flying very far.

As I am closer than 20m, does the aircraft initiate an emergency RTH? Again the manual is not clear - particularly that mention of the 20m limit again.

Hmm, I just read it again and maybe it does explain... It just. Doesn't seem very clear... I need to read again in a screen where I'm not scrolling to view the full line of text...

No Original Thought Posted at 12-11 05:01
Hmm, I just read it again and maybe it does explain... It just. Doesn't seem very clear... I need to read again in a screen where I'm not scrolling to view the full line of text...

hi,

just simulate on large free area....fly a 'river' pattern and switch off the RC
wait and see...

cheers
JJB

JJB* Posted at 12-11 07:38
hi,

just simulate on large free area....fly a 'river' pattern and switch off the RC

That's my plan... Just waiting for better flying weather. Pouring down right now and to study tomorrow

My apologies, after reading again, this time on my tablet screen where I could read it properly, I can see that the explanations of RTH in the manual are actually pretty comprehensive and pretty good. (Proof, if you need it, that not everything can be done on a 6" phone screen!)

I still think I'm going to experiment myself Inna wide open and dry location to make sure I understand properly before I head out over water, but thanks for the pointer back to the manual @Mobilehomer.

-N.O.T.

Experimentation, in a safe place, with the various RTH behaviours is a very good idea, I have been caught out several times with different models when they did not behave as I expected but, following such an event, a re read of the manual has always shown that the behaviour was correct and it was my expectations/understanding that were/was flawed.

Case in point, say for example you have the loss of connection response set to "hover" (if that is possible with your drone), what happens if you do nothing i.e. you yourself do not move to an area where you can re-establish the connection? Ditto what happens if the response is set to "land" and the drone rejects the landing site?

Today I finally managed to get out to test this situation in detail... the weather has been pretty unfavorable since my Mini 2 arrived so this was only my third outing.

I almost didn't go out as the wind was gusting pretty high at ground level, and I suspected it would be higher at height, but this turned out to be a blessing.

So, the test:

After usual checks I set RTH height to 20m so that I could keep a close eye on what the aircraft was doing (I was in a wide open field - my safe flying place).

I flew to about 6m height, 6m straight ahead. From here I flew left and right a few times so that I had covered around 100m distance, but never more than 20m away and returned to 6m away.

I noticed that the aircraft was really having to fight the wind and drifting towards me so I had to correct by flying away a bit again a few times.

(Continues...)

With the aircraft at 6m high and about 10m.in front and to the right - beyond my imaginary water line - I powered off the RC.

The Fly app correctly identified that the RC was no longer connected, and a few second later (probably the 11 seconds in the manual, but I was paying more attention to the aircraft rather than timing) the aircraft turned back towards the home point and I flew a straight line slowly back.

It did not ascend to the RTH height (presumably as closer than 20m to home.point) and did not fly at a high speed (presumably as it was close to the home point).

So, everything up to this point was as could be expected.

The aircraft, however, stopped about 2m short 9f the home point and began to descend. I had taken off from a landing pad, but the aircraft hovered about 2m from this over long grass.

At this point I turned the RC back on and it reconnected. The Fly app displayed a message that the aircraft could not land due to an unsuitable surface.

(Continues...)

I moved the landing pad to below the aircraft and landed manually without problems.

So, lessons learned.

1. If the aircraft is less than 20m away (as it is.likely to be when I fly my planned river flights) then the aircraft will NOT ascend in an emergency RTH and will not retrace it's flight to try to regain signal. It will instead perform a direct line RTH. If there are trees in the way this will be a problem!

2. Wind drift could mean that the accuracy of RTH could be a few metres off. If my take off point / RTH point is less than this distance from the water's edge I could be watching my aircraft descend into the river just out of reach.

So, choosing take off and RTH point very carefully is absolutely vital. I will need to ensure direct RTH at any height is possible AND that my RTH point is at least 3m or more from the water's edge. It will be a tricky balance.

I found the excercise very useful and enlightening, so I hope others will also find this info useful.

-N.O.T

I would suspect that 2) is a wrong conclusion and that the discrepancy is more likely to be due to inaccuracies of the GPS system. Did the homepoint reset after take off, I have the impression I have seen that happen occassionally with the likes of my Mini and Phantom 3 even when the drone had set a homepoint prior to take off.
I would also test the RTH when within 5m of the home point. I see nothing in the manual for this distance but with other drones there is an inner threshold, when inside that distance the drone simply lands where it is.

Sean-bumble-bee Posted at 12-31 11:36
I would suspect that 2) is a wrong conclusion and that the discrepancy is more likely to be due to inaccuracies of the GPS system. Did the homepoint reset after take off, I have the impression I have seen that happen occassionally with the likes of my Mini and Phantom 3 even when the drone had set a homepoint prior to take off.
I would also test the RTH when within 5m of the home point. I see nothig in the manual for this distance but with other drones there is an inner threshold, when inside that distance the drone simply lands where it is.

It's always been within a few inches of the take off point in the past.

I always hover a metre or so above the take off point to wait for the new home point to set and to check that the drone is stable and not mamlking any strange noises.

The drift distance that I was having to correct for was roughly the same as the RTH landing position was from the take off point.

Also, for these tests I did a compass and IMU calibration (as well as a humble calibration for a yaw drift test) before the first flight, and i had a good GPS lock throughout the flight (I don't have the exact numbers, but green and at least 14 sats).

But it could be just general inaccuracy rather than wind drift, and either way the same conclusion stands - I need to be a good few metres from the water's edge.

The less than 5m thing is definitely worth checking though... That could catch me out if I'm not careful.

-N.O.T.

No Original Thought Posted at 12-31 12:21
It's always been within a few inches of the take off point in the past.

I always hover a metre or so above the take off point to wait for the new home point to set and to check that the drone is stable and not mamlking any strange noises.

2. Wind drift could mean that the accuracy of RTH could be a few metres off. If my take off point / RTH point is less than this distance from the water's edge I could be watching my aircraft descend into the river just out of reach.

But it could be just general inaccuracy rather than wind drift, and either way the same conclusion stands - I need to be a good few metres from the water's edge.
The wind would have to be very strong to cause any drift - stronger than the drone can fly against.
Wind drift is not your issue.
Consumer GPS is not pinpoint accurate and will only put the drone within about 3 metres of the launch point.
Usually a little closer, and sometimes it could even be a little bit more.
That's just the variable inaccuracy of consumer GPS.

Also, for these tests I did a compass and IMU calibration (as well as a humble calibration for a yaw drift test) before the first flight,
None of that was necessary and it had no effect on what you hoped it might.

Labroides Posted at 12-31 13:14
2. Wind drift could mean that the accuracy of RTH could be a few metres off. If my take off point / RTH point is less than this distance from the water's edge I could be watching my aircraft descend into the river just out of reach.

But it could be just general inaccuracy rather than wind drift, and either way the same conclusion stands - I need to be a good few metres from the water's edge.

I'm aware that consumer GPS is not exactly accurate - though the old US military enforced reduction in accuracy was removed a good few years ago now - but every other time I have flown this drone it has been MUCH more accurate. Admittedly that's only about a dozen take offs and landings, but each was within my 60cm landing pad (actually a fire pit heat protection mat for the first few flights, but that's not relevent here).

Today the point where the drone attempted to land was a good 3m from where it took off.

And I disagree with the calibrations being unnecessary - when testing things you should always make sure any variables that can be controlled are controlled. It's about removing the unknowns. Therefore calibrating everything meant that those sensors could be better ruled out if any issues did occur. And I was less likely to receive warnings during the flight that may have affected the test.

-N.O.T.

My Mini 2 generally returns within 3 feet of launch point.

I had no issues returning to home when I did a flight from a river bank a few weeks ago but no idea what happens if the drone loses connection with the controller.

The only issue I had was when hovering over the water at ~20m above the surface, the Mini 2 would decrease in altitude but go up another metre or two and the opposite happened (increase in altitude). In the end I had to do some manual flying to try and keep it from doing both!

Mobilehomer Posted at 12-31 14:17
My Mini 2 generally returns within 3 feet of launch point.

Yup, today is the only time mine has been off by as much as it was.

I've also taken off and landed in this field more than anywhere else - as I say is my 'safe space' for flying as it's pretty rural, very few trees or other obstacles, but plenty of low level reference points for practicing manoeuvres.

It has excellent GPS reception due to how open the area is.

I could well be wrong, but I'm convinced that the strong wind played a part in it. When I did my eye height hover walkaroind inspection it was fighting the wind and drifting a couple of feet and then taking a good 10-15 seconds to slowly regain position over my landing pad (presably using visual sensors at this height, as well as GPS to do so).

No Original Thought Posted at 12-31 13:51
I'm aware that consumer GPS is not exactly accurate - though the old US military enforced reduction in accuracy was removed a good few years ago now - but every other time I have flown this drone it has been MUCH more accurate. Admittedly that's only about a dozen take offs and landings, but each was within my 60cm landing pad (actually a fire pit heat protection mat for the first few flights, but that's not relevent here).

Today the point where the drone attempted to land was a good 3m from where it took off.

but every other time I have flown this drone it has been MUCH more accurate. Admittedly that's only about a dozen take offs and landings, but each was within my 60cm landing pad

Today the point where the drone attempted to land was a good 3m from where it took off.
That's completely normal.
GPS inacuracy is variable and changes all the time.
Most of the time, it will be within 2 metres, but it can be >3 metres.
And I disagree with the calibrations being unnecessary - when testing things you should always make sure any variables that can be controlled are controlled. It's about removing the unknowns. Therefore calibrating everything meant that those sensors could be better ruled out if any issues did occur. And I was less likely to receive warnings during the flight that may have affected the test.
Saying that indicates that you don't know what those calibrations actually do and what they can affect.

If your drone was flying normally, you can't make it fly any "better" by recalibrating the IMU or compass.
If they were not properly calibrated, you'd already know it because the drone wouldn't fly properly.
IMU and compass calibration doesn't shift or get lost.

And, GPS is completely independent of any of those things and it's  the only thing that influences where the drone lands in RTH autoland.

Labroides Posted at 12-31 15:39
but every other time I have flown this drone it has been MUCH more accurate. Admittedly that's only about a dozen take offs and landings, but each was within my 60cm landing pad

Today the point where the drone attempted to land was a good 3m from where it took off.

You are missing the point about the calibrations - and I understand perfectly what they do.

A couple of points:
- The aircraft hadn't been flown for a couple of weeks.
- Calibration DOES drift. Probably not in a flight (though anything gyro based drifts significantly during turns and climbs - not relevant here, though). You have the option to calibrate these things precisely becausw they do drift.
- I had limited time today and had not flown before flying the test flight I intended. Calibrating was a precaution against getting part way through the flight and discovering that something wasn't behaving quite right.
- On my last outing I noticed that the aircraft was suffering from yaw drift (drifting left whenever yawing anti-clockwise). I wanted to eliminate anything like that if possible before this test.

(Continues...)

No Original Thought Posted at 12-31 15:52
You are missing the point about the calibrations - and I understand perfectly what they do.

A couple of points:

As for only GPS being used for RTH, I'll have to take your word for that. It may well be the case, but a lot of GPS based systems use a combination of GPS and inertial motion sensors to improve accuracy. As the Mini 2 has an IMU I expected it to use a combination of the two.

You have said yourself that consumer GPS is only so accurate. The Mini 2 seems to outperform what consumer GPS should be able to do alone so I assumed more was at play in the RTH process.

Maybe I've been lucky in the past, but others have also reported much better regular accuracy than a couple of metres.

No Original Thought Posted at 12-31 15:57
As for only GPS being used for RTH, I'll have to take your word for that. It may well be the case, but a lot of GPS based systems use a combination of GPS and inertial motion sensors to improve accuracy. As the Mini 2 has an IMU I expected it to use a combination of the two.

You have said yourself that consumer GPS is only so accurate. The Mini 2 seems to outperform what consumer GPS should be able to do alone so I assumed more was at play in the RTH process.

You are missing the point about the calibrations - and I understand perfectly what they do.

I didn't miss anything.
You have the wrong idea about the calibrations.
Neither would have the slightest effect on GPS guidance for RTH autolanding, and the drone wouldn't have flown properly if either was poorly calibrated and you'd have known.

As for only GPS being used for RTH, I'll have to take your word for that. It may well be the case, but a lot of GPS based systems use a combination of GPS and inertial motion sensors to improve accuracy. As the Mini 2 has an IMU I expected it to use a combination of the two.
The accelerometer data from the IMU is used for speed, but it's GPS alone for position.

You have said yourself that consumer GPS is only so accurate. The Mini 2 seems to outperform what consumer GPS should be able to do alone so I assumed more was at play in the RTH process.

Maybe I've been lucky in the past, but others have also reported much better regular accuracy than a couple of metres.
I've explained this already.
You cannot rely on consumer GPS to give you better than 3 metres accuracy (and sometimes even worse).
Must of the time it could be within a metre, but if you do 100 experiments, you'll find it's often also outside that.

Read this and you'll find more on the topic:
https://blog.oplopanax.ca/2014/03/measuring-gps-precision/

If you are concerned about a safe landing under RTH, launching from within a few metres of water, trees etc is unwise.

3m is a long way off, whilst i rarely use RTH let alone auto-landing since buying the Mini 2 as its not needed for me as opposed to the P4P with its precision landing of which i used a lot, i liked that function, anyway, when i did try out the auto take-off and landing, it was never more than few feet away from the take-off spot, but then i did use the helli pad so it probably distinguished that better than say grass or other blended ground.

As for what Labroides is saying, i am with him 100%. this calibrating of the compass lark is not needed and the mindset follows on from the earlier Phantom days (before my time). Even when the app says caution or warning (whatever it says), read it properly because that's not all it says, it mentions about moving the drone to another spot, as its been said before, the popup wording is poorly written and to be fair it should really say calibrate but i suppose it cannot be removed in case of a legitimate reason to do so, such as adding something to the drone, a speaker perhaps where the magnetic field is disrupted and will need to be calibrated for the inclusion of the speaker, that's just hyperthetical mind, i have no idea if even adding a speaker will require it but i suspect with the magnet it will do.

The reason DJI added the precision landing feature is because GPS is inherently sloppy (by 21st century standards). So it takes an image of the launch site and uses it to try to match on landing. Maybe 75% successful...for me anyway.

Labroides Posted at 12-31 16:48
You are missing the point about the calibrations - and I understand perfectly what they do.

I didn't miss anything.

"If you are concerned about a safe landing under RTH, launching from within a few metres of water, trees etc is unwise."

I admit to being unwise and do that a lot of the time ;-) So far, no problems.

Labroides Posted at 12-31 16:48
You are missing the point about the calibrations - and I understand perfectly what they do.

I didn't miss anything.

@Labroides,

You HAVE missed the point. Please stop talking to me like an idiot.

I DO NOT expect compass and IMU calibration to affect the function or accuracy of the GPS.

I calibrated these to ensure as much as possible that nothing else in the flight would be adversely affected by miscalibration.

I WOULD NOT have known the airaft was misbehaving due to any miscalibration as it was in the bag right up until it was flown for this flight. As far as I am aware the Mini 2 does not have a telepathy unit to tell users of its status while powered off and stored.

The calibration was precautionary to prevent any other discrepancies during a flight which I wanted to be warning free. Any warning would have meant the aircraft had been in a 'not normal' state at some point before the RTH was forced and I did not want that - I wanted as close to a controlled test environment as possible.

Bashy Posted at 12-31 20:02
3m is a long way off, whilst i rarely use RTH let alone auto-landing since buying the Mini 2 as its not needed for me as opposed to the P4P with its precision landing of which i used a lot, i liked that function, anyway, when i did try out the auto take-off and landing, it was never more than few feet away from the take-off spot, but then i did use the helli pad so it probably distinguished that better than say grass or other blended ground.

As for what Labroides is saying, i am with him 100%. this calibrating of the compass lark is not needed and the mindset follows on from the earlier Phantom days (before my time). Even when the app says caution or warning (whatever it says), read it properly because that's not all it says, it mentions about moving the drone to another spot, as its been said before, the popup wording is poorly written and to be fair it should really say calibrate but i suppose it cannot be removed in case of a legitimate reason to do so, such as adding something to the drone, a speaker perhaps where the magnetic field is disrupted and will need to be calibrated for the inclusion of the speaker, that's just hyperthetical mind, i have no idea if even adding a speaker will require it but i suspect with the magnet it will do.

Take off any landing for this test was from a StartRC orange and black helipad, but the aircraft did not turn to over the pad so the downward sensors would likely not have seen the pad.

I don't know the FoV of those downward sensors, though. The main camera would have seen the pad, but I suspect the downward vision system is likely a narrower FoV.

At 3m away horizontally and a height of around 5m would the pad have been visible and within the range that the software would recognise as valid?

It's odd that the RTH landings yesterday were all 9ff by comparable distances and in the same direction (into wind almost to the degree) when previously they had been far more accurate.

GaryDoug Posted at 12-31 20:13
"If you are concerned about a safe landing under RTH, launching from within a few metres of water, trees etc is unwise."

I admit to being unwise and do that a lot of the time ;-) So far, no problems.

It only matters if you have the drone coming back by itself.
If you never lose signal it's no problem at all.

GaryDoug Posted at 12-31 20:08
The reason DJI added the precision landing feature is because GPS is inherently sloppy (by 21st century standards). So it takes an image of the launch site and uses it to try to match on landing. Maybe 75% successful...for me anyway.

It was 100% successful for me within inches on the orange pad

No Original Thought Posted at 12-31 21:23
@Labroides,

You HAVE missed the point. Please stop talking to me like an idiot.

You HAVE missed the point. Please stop talking to me like an idiot.
I haven't missed anything, except that I assumed you might respond positively to factual information.
I calibrated these to ensure as much as possible that nothing else in the flight would be adversely affected by miscalibration.
And that was unnecessary.

I WOULD NOT have known the airaft was misbehaving due to any miscalibration as it was in the bag right up until it was flown for this flight. As far as I am aware the Mini 2 does not have a telepathy unit to tell users of its status while powered off and stored.
The calibration was precautionary to prevent any other discrepancies during a flight which I wanted to be warning free. Any warning would have meant the aircraft had been in a 'not normal' state at some point before the RTH was forced and I did not want that - I wanted as close to a controlled test environment as possible.
If you had flown it successfully in the past, it would have flown just as well then.
I haven't calibrated a thing on my #1 drone in 5 years of professional flight.
Calibration of the IMU and compass doesn't drift or get lost.
Understanding what the calibrations actually do makes your flying safer than just unnesessarily recalibrating things because you imagine it's a good idea.

No Original Thought Posted at 12-31 21:32
Take off any landing for this test was from a StartRC orange and black helipad, but the aircraft did not turn to over the pad so the downward sensors would likely not have seen the pad.

I don't know the FoV of those downward sensors, though. The main camera would have seen the pad, but I suspect the downward vision system is likely a narrower FoV.

Take off any landing for this test was from a StartRC orange and black helipad, but the aircraft did not turn to over the pad so the downward sensors would likely not have seen the pad.

At 3m away horizontally and a height of around 5m would the pad have  been visible and within the range that the software would recognise as  valid?
Do you realise that your Mini 2 doesn't have Precision Landing?
It's downward sensors just identify the terrain below the drone as suitable/not suitable for landing.
They have nothing to do with guidance to the launch point and the main camera isn't used.

It's odd that the RTH landings yesterday were all 9ff by comparable distances and in the same direction (into wind almost to the degree) when previously they had been far more accurate.
It's not odd at all and entirely in accordance with what I've been trying to get across to you about GPS guidance and RTH auto landing.
But that's the point that you just cannot get.

But unless you lose signal and have your launch point close to water or an obstacle, none of that matters anyway.
You can land your drone wherever you choose rather than relying on blind programming and fuzzy GPS (in)accuracy.

No Original Thought Posted at 12-31 21:23
@Labroides,

You HAVE missed the point. Please stop talking to me like an idiot.

Why was it at a height of only 5m, does RTH even work that low? never tried it to be fair, so a valid question.  When i tested the RTH and landing test on my mini 2, it was from a distance of 300m at a height of 50m, it was quite breezy too, around 25mph gusts, I had to cancel that landing when i knew it was going to miss the pad by a few feet, if i was to guess, on subsequent tests it was around a max of 5ft, certainly not 10ft but having said that, i only did about 3/4 tests, perhaps it could end up further away...  

The main concern is that you did a compass calibration when there is absolutely no reason to do so whatsoever unless you've added something to the drone?

The drone does NOT create a poor calibration stuck in its bag (unless i misunderstood what you're trying to say there, it didn't make a lot of sense if I'm honest), the drone self tests on power up, it checks for magnetic interference during this stage, once power up is complete you can stick the drone anywhere and take off, car roof etc, I'm not advising to do so mind. This is why, when you get the calibration error on screen, you should always switch the drone off, then move it away from any possible source of interference, then power it up again, this is one reason i always power my mini 2 up in the air at arms length, away from the body and controller/device, there's a knack to turning it on one handed BTW, if you get the error again after moving it and switching it back on, that only means that you are still near magnetic interference, keep trying the steps mentioned.

Calibrating the compass can in fact cause you more issues than not doing so by creating a poor calibration.

Advice: take it or leave it but i would advise you to do one final compass calibration, take it to a wide open grassy area, keep ac at arms length and perform the calibration, that way you know that you should have created the best possible calibration.

Whilst Labroides bedside manner isn't the greatest at times (he's no Dr, for sure lol) and shouting will only provoke him, ya don't want that ;), he does know his stuff, if I was you I would take heed but not to heart.

Now that you are somewhat wiser, perhaps it may prevent a future mishap, or, you can carry on as you are, i will be one of the 1st to say, "told ya so " though lol