MagFieldMonitor.java

package com.bestpnd.MagneticFieldMeter;

import android.app.Activity;
import android.os.Bundle;
import android.hardware.*;
import android.widget.TextView;
import java.lang.Float;

public class MagFieldMonitor extends Activity
{
	static SensorEventListener sensorEL;
	static SensorManager sensorM;
	static Sensor sensor;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

	  sensorM = (SensorManager)this.getSystemService(this.SENSOR_SERVICE);

	  sensorEL = new SensorEventListener() {
				
				public void onAccuracyChanged(Sensor sensor, int accuracy) {

				}
				
				public void onSensorChanged(SensorEvent event) {
					TextView x_field = (TextView) findViewById(R.id.widget40);
					TextView y_field = (TextView) findViewById(R.id.widget41);
					TextView z_field = (TextView) findViewById(R.id.widget42);

					x_field.setText(Float.toString(event.values[0]));
					y_field.setText(Float.toString(event.values[1]));
					z_field.setText(Float.toString(event.values[2]));
				}
	  		 };
	  sensor = sensorM.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
	  sensorM.registerListener(sensorEL, sensor, SensorManager.SENSOR_DELAY_NORMAL); // <---- offending line?
    }
}