Measure magnetic field along X, Y, and Z axes
Simulink Support Package for Android Devices / Sensors
The Magnetometer block reads the strength of the magnetic field around an Android™ device. The built-in magnetometer sensor on the Android device measures the magnetic field along the X, Y, and Z axes. The block outputs the magnetic field as a 1-by-3 vector in microtesla (μT).
This illustration shows the orientation of the X, Y, and Z axes for a typical Android mobile phone.
This illustration shows the orientation of the X, Y, and Z axes for a typical Android tablet.
During simulations without hardware, this block outputs zeros. For more information, see Block Produces Zeros or Does Nothing in Simulation (Simulink).
Port_1— Strength of magnetic field around Android device
The block outputs the strength of the magnetic field as a 1-by-3
vector. The elements of the vector represent the measurements of the
magnetic field in
μT along the X, Y, and Z axes of
the magnetometer sensor on the Android device.
Sample time— How often the block reads data
-1| any positive integer
Specify how often the block reads data from the magnetometer, measured in
seconds. When you specify this parameter as
Simulink® determines the best sample time for the block based on the
block context within the model.
This example shows how to read the strength of the magnetic field around an Android device.
This Simulink model includes a Magnetometer block and a Data Display block. The Magnetometer block reads the strength of the magnetic field from the built-in magnetometer sensor on your Android device. The block outputs the magnetic field as a 1-by-3 vector. The Data Display block accepts the vector and displays the values on your Android device.
To run the model:
Connect an Android device to your computer with a USB cable.
Install the Simulink Support Package for Android Devices as described in Install Support for Android Devices.
In the Modeling tab of the toolstrip, select Model Settings.
In the Configuration Parameters dialog box, select Hardware Implementation.
Set the Hardware board parameter to
Device. This selection automatically populates the parameters
in the Hardware board settings with the default values
From the Groups list under Target hardware resources, select Device options.
From the Device list, select your Android device. If your device is not listed, click Refresh.
If your device is not listed even after clicking the
Refresh button, ensure that you have enabled
the USB debugging option on your device. To enable
USB debugging, enter
androidhwsetup in the MATLAB® Command Window and follow the onscreen
Click Apply to save your changes. Click OK.
On the Simulink editor toolbar, click the Build Model button . The model is loaded and starts running on the device. The values from the mangnetometer are displayed on the device screen. Move your Android device and observe the change in the magnetic strength along all three axes.