HMC5883L is a surface-mount, multi-chip module designed for low-field magnetic sensing with a digital interface for applications such as lowcost compassing and magnetometry.
I2cConnectionSettings settings = new I2cConnectionSettings(1, Hmc5883l.DefaultI2cAddress);
I2cDevice device = I2cDevice.Create(settings);
using (Hmc5883l sensor = new Hmc5883l(device))
{
// read direction vector
Vector3 directionVector = sensor.DirectionVector;
// read heading
double heading = sensor.Heading;
// read status
Status status = sensor.DeviceStatus;
}
https://cdn.datasheetspdf.com/pdf-down/H/M/C/HMC5883L-Honeywell.pdf