Minimal Compass

Support

Minimal Compass for Android

Most compass problems are calibration problems, and they are fixable in about ten seconds. Start here — and if none of this helps, email me directly and I will answer.

The heading looks wrong

A phone magnetometer measures the magnetic field around it, and it will faithfully report the field of whatever is nearest — which is often not the Earth.

• Calibrate. Hold the phone and trace a figure of eight in the air a few times, rotating your wrist as you go. The confidence label under the heading should climb within a few seconds.
• Step away from metal and magnets. Car dashboards, desks with steel frames, laptops, speakers, wireless chargers and magnetic phone cases and mounts all bend the reading badly. A magnetic case is the single most common cause, and no app can correct for it.
• Check what the app is telling you. If it shows UNRELIABLE or NO SENSOR SIGNAL, it has already detected the problem and is warning you rather than guessing.

What is the difference between MAG and TRUE?

MAG is magnetic north — where the needle points. TRUE is geographic north — where the pole actually is. The gap between them is called declination and can be more than ten degrees depending on where you are.

Tap the MAG label to switch. The first tap asks for approximate location permission, because the correction depends on where you are standing; the app takes one coarse fix, works out the correction angle, and keeps only that angle. Your position is never stored or sent anywhere — see the privacy policy.

The tag never changes to TRUE

Either location permission is off, or no position fix arrived. Check Android Settings → Apps → Minimal Compass → Permissions → Location, and make sure location services are switched on system-wide. Indoors, a first fix can take longer than the app is willing to wait; step near a window and try again.

AR mode

Raise the phone towards vertical and the compass hands over to a camera view with the cardinal directions floating over the scene. Lower it and the flat rose returns.

• It opens when I don't want it to. Turn off automatic switching in the settings dialog; you can still open AR deliberately.
• The screen is black. Another app is probably holding the camera — close it and reopen AR.
• The camera permission screen won't accept my tap. After two refusals Android blocks further prompts from inside the app. The button changes to Open Settings, which takes you to the place where it can still be granted.

The bubble level

Swipe left from the compass. Lay the phone on the surface you are checking; the bubble centres when it is flat. For a vertical surface, hold the phone flat against it.

The home screen widget

Long-press an empty area of the home screen, choose Widgets, find Minimal Compass and drag it into place. The tile is a shortcut, not a live readout — a widget cannot hold the magnetometer open, so any heading it displayed would be a stale guess taken while the phone was face-down in a pocket. Showing nothing is more honest than showing that.

Daylight mode

The settings dialog has a Daylight switch: a maximum-contrast white screen for reading the compass in direct sun. It is separate from your system light and dark theme, which the app otherwise follows.

Which devices are supported

Android 7.0 (API 24) and later, on phones that have a magnetometer. Devices without one cannot run a compass at all and are filtered out on Google Play. AR mode additionally needs a rear camera; everything else works without one.

Reporting a bug

Email is the fastest route. Useful details:

• Phone model and Android version.
• What you expected and what happened instead.
• Whether the confidence label was showing anything at the time.
• Whether it happens every time or occasionally.

Crash reports arrive automatically and anonymously, so a crash is usually already visible to me — but they carry no note of what you were trying to do, and that context is often what makes one fixable.