Hello

Yesterday i did power the spark inside house just to download some photos from SD.

When i power up and placed it at the table i realised that the spark and the iphone dji go4 direction of the aircraft was not 100% correct mayby 15 degres to the left. Then i picked the spark and rotate it a few times and after it the compass direction  at djigo became exacttly perfect. (Did not calibrate)

Was it coincident? Should we make some kind of pre flight moves to get better compass feedback?

There are some rumors that in fact, spark has two compasses onboard (compass redundancy) but only readings from one of them is used by firmware and second compass is not used (rear motors parasit?! , low-pass filtering? Firmware limitation?) simple. Any measure to improve compass resistance to interferences is higly appreciated and enhances flight safety significantly.

Actually, it is related with the mobile device compass. Calibrate the mobile compass will be helpful.

DJI Susan Posted at 2017-9-9 01:12
Actually, it is related with the mobile device compass. Calibrate the mobile compass will be helpful.

hello.

I did another test today placed the spark in the table and the mobile (iphone6). At app it was showing the spark was 45 degrees to the left and it was at 0 degrees. I  rotated the spark 3 time and placed at same position the error between the app and the spark position continued. The i mode the phone 3 times and the error disappear.  Some apps prompt to make a compass calibration on startup the dji go does not. Can it make any impact at flying and the spark sunddenly have compass error?

ZukySpark Posted at 2017-9-9 02:09
hello.

I did another test today placed the spark in the table and the mobile (iphone6). At app it was showing the spark was 45 degrees to the left and it was at 0 degrees. I  rotated the spark 3 time and placed at same position the error between the app and the spark position continued. The i mode the phone 3 times and the error disappear.  Some apps prompt to make a compass calibration on startup the dji go does not. Can it make any impact at flying and the spark sunddenly have compass error?

Hi ZukySpark,

Yes compass issues can have a huge (and unwanted) impact on flight.  I do not fly if my device is reporting compass issues.  The most common cause for me is that I'm trying to launch from a location that has a lot of material which impacts compass functionality.  Top of a parking garage for example (rebar in the cement).  I also got errors when I tried to take off from a box which contained an old stereo and speakers.  I even get compass warnings when I turn on my spark on my work desk.

Based on your description, it sounds like you are trying to calibrate your compass indoors.  I recommend you step outside to a location which is pretty clear of manmade structures.  Even a small backyard is sufficient.

Assuming that you successfully calibrate your compass, henceforth it should rarely ever require recalibration.  If and when you get errors on startup, that means that you are starting your spark (and trying to launch) in an unsuitable location, not that the compass is bad or needs to be recalibrated.  The spark compass is extremely sensitive.  Even a minor amount of metal can have a big impact.

Best response to a compass error is to relocate your launch site.

DJI Susan Posted at 2017-9-9 01:12
Actually, it is related with the mobile device compass. Calibrate the mobile compass will be helpful.

How could the compass of the mobile device impact the Spark inflight? Never thought about that..

I wouldn't think the phones compass would matter for flight. I think most of my flights have been done with my phones compass calibration functionality disabled. iPhone by default has it turned off and only if you turn location services on does it also enable compass cal.  I haven't had any major problems with my drone in this state

I too didn't know/understand/believe that the phone compass had any part in the system.  DJI moderators:  what role does the phone's compass play?

Charles Adams Posted at 2017-9-9 07:37
I too didn't know/understand/believe that the phone compass had any part in the system.  DJI moderators:  what role does the phone's compass play?

I really want to know this as well. My ohone compass isnt the most accurate...

The smart phone is more of a monitor. It's more about your air craft's compass.

I didn't realise this either but the phone compass is used to determine the orientation your phone is heading. I think that is taken into account to display the heading in the compass window in the app(bottom left). If e.g. the phones compass is off by a couple of degrees and you use that to fly towards you, you might think it's coming straight at you while in reality it's not.

Does this type of "solid state" compass need some motion to get a "lock"?  I have had my iPhone compass tell me I needed to rotate the phone before it would give an accurate reading.

And yes many things can cause interference to anything that relies on a radio type signal.  My satellite radio (SirusXM) routinely just does not work in one spot outside of town that is about +/- 150 feet from this location.  There is a commercial printing factory near the spot.  Maybe it generates some sort of electrical signal that interferes with satellite radio which is fairly low power.

I am not an electrical engineer but "just saying".

And yes I do seem to have random compass problems but generally when I am not near where I last flew.  For me if the Spark is acting a bit "funky" (compass issues after calibration, video jitter, etc.)  I shut off the Spark, shut off the controller, and kill DJI Go on my iPhone and start over.  This process seems to be pretty reliable.  It takes a minute or so but I figure I get that time back by not looking for a fly away.

You can read about solid state compasses and gyroscopes on Wikipedia:  https://en.wikipedia.org/wiki/Compass

ZukySpark Posted at 2017-9-9 02:09
hello.

I did another test today placed the spark in the table and the mobile (iphone6). At app it was showing the spark was 45 degrees to the left and it was at 0 degrees. I  rotated the spark 3 time and placed at same position the error between the app and the spark position continued. The i mode the phone 3 times and the error disappear.  Some apps prompt to make a compass calibration on startup the dji go does not. Can it make any impact at flying and the spark sunddenly have compass error?

The angel will appear when the mobile compass and aircraft compass are not agreed. It is not related with normal flight directly. No worries. The tutorial video might be helpful to understand the Attitude Indicator.

A wee bit off topic, I was flying with friends yesterday. One guy's Spark was on the roof of his car and he was wondering why he had a compass error warning. I moved it to on the ground about 20 feet away and miraculously, the error went away - imagine that.

added this to my preflight schedule.  Calibrate my iphone and spark when one asks for a calibration.  Never thought of the iphone compass could cause flight issues.

Sparky_17 Posted at 2017-9-11 07:43
added this to my preflight schedule.  Calibrate my iphone and spark when one asks for a calibration.  Never thought of the iphone compass could cause flight issues.

I tried to find a means of calibrating the Verizon Galaxy S7 Edge compass, and it appears to be an option not directly available to the user.  I recall being prompted to calibrate the phone compass before, but I don't recall the circumstances.

I don't believe I have a need to calibrate it, but this conversation made me curious about the phone's compass.

Charles Adams Posted at 2017-9-11 07:52
I tried to find a means of calibrating the Verizon Galaxy S7 Edge compass, and it appears to be an option not directly available to the user.  I recall being prompted to calibrate the phone compass before, but I don't recall the circumstances.

I don't believe I have a need to calibrate it, but this conversation made me curious about the phone's compass.

Same here, curiously got the best of me .. lol  iphone has a cmpass app, which when opened will request calibration if needed; kind of like the Go4 app when you start up your spark.