package com.example.sensor01;

import java.util.List;

import android.hardware.Sensor;

import android.hardware.SensorEvent;

import android.hardware.SensorEventListener;

import android.hardware.SensorManager;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.widget.TextView;

public class MainActivity extends Activity implements SensorEventListener{

    private static final float NS2S = 1.0f / 1000000000.0f;

    private float timestamp;

    private SensorManager mSensorManager;

    private TextView textview;

    private float angle2 = 0,angle0 = 0,angle1 = 0;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        textview = (TextView) findViewById(R.id.content);

        mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);

        Sensor sensor  = mSensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE);

        mSensorManager.registerListener(this, sensor, SensorManager.SENSOR_DELAY_NORMAL);

    }

    @Override

    public void onAccuracyChanged(Sensor arg0, int arg1) {

        // TODO Auto-generated method stub

    }

    @Override

    public void onSensorChanged(SensorEvent event) {

        float[] values = new float[3];

        if(0 != timestamp){

            final float dT = (event.timestamp - timestamp) * NS2S;

            if (event.sensor.getType() == Sensor.TYPE_GYROSCOPE){

                //三个方向的角速度

                values = event.values;

            }

            //三个方向转过的弧度

            angle0 += values[0] * dT;

            angle1 += values[1] * dT;

            angle2 += values[2] * dT;

            //三个方向将弧度转换为角度，即 角度=弧度除以π再乘以180 弧度=角度乘以π后再除以180

            float anglex = (float) Math.toDegrees(angle0);//前后垂直翻转的角度（相对于初始位置，即第一次取值）

            float angley = (float) Math.toDegrees(angle1);//左右翻转的角度（相对于初始位置，即第一次取值）

            float anglez = (float) Math.toDegrees(angle2);//左右摇摆的角度（相对于初始位置，即第一次取值）

            textview.setText(String.valueOf(anglex) + "   "

            + String.valueOf(angley) + "  " + String.valueOf(anglez));

        }

        timestamp = event.timestamp;

    }

}