Online Help > Compass

Orientation & Compass

The compass feature uses the magnetic sensor of your device (if available) to give you orientation information.

To turn on the compass, you can either:

  • Long-press the “Compass” menu button ;
  • Click on the sub-menu toggle .

The “Compass” menu button color lets you know the current state:

  • When the icon is white, the “Compass” is turned off. Long-press the button to turn it on;
  • When the icon is green, the “Compass” is turned on. Long-press the button to turn it off.


The compass menu

Click on the “Compass menu button to display the compass menu, composed of the following items:

  • The “Compass button opens the compass details window;
  • The “Compass toggle lets you turn on or off the compass feature easily;
  • The “Display compass check-box controls either or not to display a compass on the map;
  • The “Rotate the map check-box controls either or not to rotate the map based on the compass north to match the real direction you are looking at;
  • The “Current heading check-box controls either or not to display an information box on the map with your current heading.

You can un-check both “Display compass” and “Rotate the map” check-boxes to display a small current heading arrow .


The compass view

The “compass view” gives you the following information:

  • The true (geographic) north direction, pointed by the red arrow .
  • The precise heading arrow , when this one is between -20° and +20°, including mils graduation;
  • A pitch and roll level , helping you to keep the device flat;
  • The magnetic declination at your current location , which is the difference between the magnetic north and the geographic (map) north. The application uses either the last known location of your device if any, or the screen center location. This value is computed each time you activate the compass;
  • The direction to the target, if a location is set as target.

The compass settings

By default, the compass has a moving rose and graduations (the “Topochaix” style). You can change it to a moving needle and still graduations :

  • Click on the “Settings icon to open the settings dialog;
  • Click on the style list and select “Standard”;
  • Click on “OK to validate.


Problems with the compass

Compass won't turn on
compass-error-sensor.jpg If you can't turn on the compass, it means that your device doesn't have a built-in magnetic sensor, which is required to get the direction of the north. Recent versions of the application display this message when this case occurs:
Note that you can still use the map rotation using the GPS (if available), from the Positioning menu.

Compass gives incorrect direction
When using the application compass (just like with mechanical compass), be sure to handle your device in the horizontal position, the screen facing the sky.
If you still get a wrong direction, it usually means that the magnetic sensor needs to be calibrated. This is fast and easy:

  • Turn on the compass;
  • Rotate your device in the air in all directions;
  • Done!


Wrong magnetic declination
If calibrating the compass doesn't help, or if you see a strange constant offset in the direction, check the magnetic declination . As explained above, the application needs to know your approximate current location to compute a valid magnetic declination. Most of the time you just need to be sure that the map points your current location to fix your problem.
If you still believe the computed declination is incorrect or already applied by your device, you can turn off this computation as explained in the settings sections.

Inverted poles
On some devices, when changing the screen orientation of 180° (jumping to the opposite screen orientation, ie landscape right to landscape left without the intermediate portrait orientation), the compass direction is inverted. Be sure to always select the portrait orientation, even temporarily.

Sensor issues
In addition to the magnetic sensor, your device may use other sensors to compute a precise and noiseless north direction. Some sensors may not work or may not be as reliable as expected on some devices and some may be wrongly reported as available. In some cases, changing the default orientation computation method may provide a better accuracy.

To do so:

  • Tap on the Settings icon to open the settings dialog;
  • Tap on More ;
  • Tap on the currently used Sensor and choose another one;
  • Tap on Ok .

The list of available sensors depends on the device and system version, but usually contains:

  • ROTATION_VECTOR which uses the magnetometer, the accelerometer and the gyroscope sensors. When available, it usually provides the more precise value;
  • MAGNETIC_FIELD which uses the magnetometer and the accelerometer sensors;
  • ORIENTATION which uses a device-dependent internal computation.