Home > Electronic Compass > Application Notes > Test for Android devices with an onboard electric compass

Test for Android devices with an onboard electric compass


1. What is an electric compass test?

 You can conduct a test to determine whether the electric compass mounted in an Android device is working normally or not.


2. Test app “AMI 2D Plot”

 Download the test app for electric compasses onboard Android devices, AMI2DPlot, at the below link.

 ・AMI2DPlot.apk (download)

 Once downloaded, you must install using the user app install process since this app is not on Google Play.


 Below is a brief description of its use

The functionality includes a 2D plot (can be switched between XY, XZ, and YZ) and logging.

When you select “Start,” the sensor begins operating.


In this state, in a location with good magnetic fields, plot 8 points or otherwise rotate the device in 2 directions, one revolution vertically and then one revolution horizontally, and it will automatically calibrate.


If the color of the plot traced by the magnetic field ends up red, it has not calibrated because it was not accurate enough. Rotate the device again until the plot turns green.


The display of the graph can be controlled by tapping the screen. If you tap inside the gauge of the circle drawn on the screen, the circle gauge will get smaller. If you tap immediately outside the circle gauge, it will get larger.


If you perform a single touch and drag, the range of the displayed graph will move.

If you perform a dual touch and drag, you can shrink the graph's scale.


The log is saved on the Android device in a file named “/data/data/us.aichisteel/files/filename”.

If the log checkbox is checked, it will log from the time the start button that is to the upper right of the file name is pressed until the stop button is pressed.

※ In creating this app, we used Android graph creation middleware http://www.achartengine.org .