EVERY TIME is start the DJI Go 4 app on my Iphone SE and then hit "Enter Device", I immediately get the option page with the Calibrate Compass box highlighted.
I have calibrated many time, but it makes no difference, it still comes up every time...  I fly mostly at home so may be there is some local interferance?  BUT on the other hand, I have taken it well away from home, way out in a field with nothing around but empty space, and I still get the same result.

Sometimes I just ignore it and fly anyway, other time I dutifully calibrate.... usually if I move elsewhere.

Is this normal, or is my app or spark acting up.... or maybe I'm in the magnetic twilight zone.  Help me obie wan kanobi, you're my only hope.

change your phone

Hi, sir. Please ensure that you fly in a place without interference, including high voltage line, factories, metallic material things. Please try to change an environment and see if the sign gone. Keep us updated, thanks.

Your screen shot shows the Calibrate button but it doesn’t say you need to calibrate. Note right of the calibrate button it said: Normal. I think everyone get this screen and that everything is fine. However, on the top of your screen there is an Overal Status warning. What does it show when you press it?

S.J Posted at 2017-12-11 21:48
change your phone

It is a brand new Iphone SE with the latest A9 processor and 32 gigs.

I get the same thing sometimes, but it doesn't seem to be a warning just another weird thing the app does.  It worried me too, but several flights later, no problem.  (iPhone 6s with IOS 11.2)

To check your compass before flight, click the 3 dots on the top right, touch the first icon (quadcopter X) go to Advanced Settings, Sensors, then at the top select Compass.  This shows you the current status.  It never hurts to calibrate the IMU and compass once in a while even when it doesn't ask you to.  I always do a quick shake down flight to make sure it's acting normal before I start flying higher or further away.  Good luck!

That doesn’t mean calibrate, it’s just a short Cut to calibration. Do not calibrate!!!!