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How Does SkySafari Acquire Compass Data From A Phone's Solid-State Sensor?

Using Compass on iPhone 8+. First, move away from any nearby metal object which will be causing interference; light pole, car, overhead power lines,, protective cover on device, ect.
Question 1, When the device compass is tracking wrong (more than ten degrees), is it necessary to close Skysafari (SS) and reopen SS after calibating the compass? Or just turn off SS compass, calibrate, then re-activate SS compass.
As I understand, when you turn on SS compass, then SS retrieves data from phone’s solid-state sensor (compass).
Question 2, what is mechanism by which SS conpass gets signal, does SS have time intervals and keep interacting with phones solid-state sensor? Or one-and-done?

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    Bill Tschumy

    These digital compasses are wild and mysterious things.  Sometimes I will have the compass acting up and I will start the compass in another app just to see if that is misbehaving as well.  Often this will start making the compass in SS work as well.  The conversation is true as well, that a misbehaving compass in the other app is sometime fixed by starting it in SS.

    #1. No, it should not be necessary to restart SkySafari after calibrating the compass.  I generally calibrate while the compass is on in SS.  I will turn it on using the toolbar button and then rotate the device over along all 3 axes.  Be careful not to touch the screen while doing so as this will turn the compass off.

    #2. This is really a pretty technical question but the simple answer is we ask the compass hardware for its current readings after every refresh of the screen (generally 30-60 times a second).

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