.. highlight:: csharp

Magnetometer
============
A magnetometer measures magnetic field strength, typically of the Earth's magnetic field, using the Hall Effect.  The data from this sensor can be 
combined with the BMI160 data to provide 9 degrees of freedom for a :doc:`sensor_fusion` algorithm.  

A few select boards, namely the CPro and MetaMotion boards, have the 
`BMM150 <https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMM150-DS001-01.pdf>`_ geomagnetic sensor, represented by the 
`IMagnetometerBmm150 <http://mbientlab.com/docs/metawear/csharp/1/interfaceMbientLab_1_1MetaWear_1_1Sensor_1_1IMagnetometerBmm150.html>`_ interface.  

::

    using MbientLab.MetaWear.Sensor;

    IMagnetometerBmm150 magnetometer = metawear.GetModule<IMagnetometerBmm150>();

Configuration
-------------
Bosch provides 4 recommended configurations for the BMM150 chip that control the data rate, current, and noise.  

================ ==== =============== ===============================
Preset           ODR  Average Current Noise 
================ ==== =============== ===============================
LOW_POWER        10Hz 170µA           1.0µT (xy axis), 1.4µT (z axis)
REGULAR          10Hz 0.5mA           0.6µT
ENHANCED_REGULAR 10Hz 0.8mA           0.5µT
HIGH_ACCURACY    20Hz 4.9mA           0.3µT 
================ ==== =============== ===============================

::

    using MbientLab.MetaWear.Sensor.MagnetometerBmm150;

    // use the regular preset configuration
    magnetometer.Configure(Preset.Regular);

The ``Configure`` is overload to allow advanced useres the ability manually configure each of the sensor parameters.

Magnetic Field Data
-------------------
The BMM150 measures magnetic field strength in Tesla (T) and its data is represented by the 
`MagneticField <http://mbientlab.com/docs/metawear/csharp/1/classMbientLab_1_1MetaWear_1_1Data_1_1MagneticField.html>`_ class.  

::

    await magnetometer.MagneticField.AddRouteAsync(source => 
        source.Stream(data => Console.WriteLine(data.Value<MagneticField>().ToString()))
    );