Android计步功能的实现代码

public class MainActivity extends AppCompatActivity implements StepCallBack{
 .........
 @Override
 public void Step(int stepNum) {
  // 计步回调
  stepText.setText("步数:" + stepNum);
 }

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);  
  setContentView(R.layout.activity_main);
  stepText = (TextView) findViewById(R.id.step_text);

  // 开启计步监听, 分为加速度传感器、或计步传感器
  stepSensor = new StepSensorPedometer(this, this);
  if (!stepSensor.registerStep()) {
   Toast.makeText(this, "计步传传感器不可用！", Toast.LENGTH_SHORT).show();
   stepSensor = new StepSensorAcceleration(this, this);
   if (!stepSensor.registerStep()) {
    Toast.makeText(this, "加速度传感器不可用！", Toast.LENGTH_SHORT).show();
   }
  }
 }
 .......
 }

/**
 * 计步传感器抽象类, 子类分为加速度传感器、或计步传感器
 */
public abstract class StepSensorBase implements SensorEventListener {
 private Context context;
 public StepCallBack stepCallBack;
 public SensorManager sensorManager;
 public static int CURRENT_SETP = 0;
 public boolean isAvailable = false;

 public StepSensorBase(Context context, StepCallBack stepCallBack) {
  this.context = context;
  this.stepCallBack = stepCallBack;
 }

 /**
  * 开启计步
  */
 public boolean registerStep() {
  if (sensorManager != null) {
   sensorManager.unregisterListener(this);
   sensorManager = null;
  }
  sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
  registerStepListener();
  return isAvailable;
 }

 /**
  * 注册计步监听器
  */
 protected abstract void registerStepListener();

 /**
  * 注销计步监听器
  */
 public abstract void unregisterStep();
}

/**
 * 计步传感器
 */
public class StepSensorPedometer extends StepSensorBase {
 private final String TAG = "StepSensorPedometer";
 private int lastStep = -1;
 private int liveStep = 0;
 private int increment = 0;
 private int sensorMode = 0; // 计步传感器类型

 public StepSensorPedometer(Context context, StepCallBack stepCallBack) {
  super(context, stepCallBack);
 }

 @Override
 protected void registerStepListener() {
  Sensor detectorSensor = sensorManager.getDefaultSensor(Sensor.TYPE_STEP_DETECTOR);
  Sensor countSensor = sensorManager.getDefaultSensor(Sensor.TYPE_STEP_COUNTER);
  if (sensorManager.registerListener(this, detectorSensor, SensorManager.SENSOR_DELAY_UI)) {
   isAvailable = true;
   sensorMode = 0;
   Log.i(TAG, "计步传感器Detector可用！");
  } else if (sensorManager.registerListener(this, countSensor, SensorManager.SENSOR_DELAY_UI)) {
   isAvailable = true;
   sensorMode = 1;
   Log.i(TAG, "计步传感器Counter可用！");
  } else {
   isAvailable = false;
   Log.i(TAG, "计步传感器不可用！");
  }
 }

 @Override
 public void unregisterStep() {
  sensorManager.unregisterListener(this);
 }

 @Override
 public void onSensorChanged(SensorEvent event) {
  liveStep = (int) event.values[0];
  if (sensorMode == 0) {
   StepSensorBase.CURRENT_SETP += liveStep;
  } else if (sensorMode == 1) {
   StepSensorBase.CURRENT_SETP = liveStep;
  }
  stepCallBack.Step(StepSensorBase.CURRENT_SETP);
 }

 @Override
 public void onAccuracyChanged(Sensor sensor, int accuracy) {
 }
}

public class StepSensorAcceleration extends StepSensorBase {
 private final String TAG = "StepSensorAcceleration";
 //存放三轴数据
 final int valueNum = 5;
 //用于存放计算阈值的波峰波谷差值
 float[] tempValue = new float[valueNum];
 int tempCount = 0;
 //是否上升的标志位
 boolean isDirectionUp = false;
 //持续上升次数
 int continueUpCount = 0;
 //上一点的持续上升的次数，为了记录波峰的上升次数
 int continueUpFormerCount = 0;
 //上一点的状态，上升还是下降
 boolean lastStatus = false;
 //波峰值
 float peakOfWave = 0;
 //波谷值
 float valleyOfWave = 0;
 //此次波峰的时间
 long timeOfThisPeak = 0;
 //上次波峰的时间
 long timeOfLastPeak = 0;
 //当前的时间
 long timeOfNow = 0;
 //当前传感器的值
 float gravityNew = 0;
 //上次传感器的值
 float gravityOld = 0;
 //动态阈值需要动态的数据，这个值用于这些动态数据的阈值
 final float initialValue = (float) 1.7;
 //初始阈值
 float ThreadValue = (float) 2.0;

 //初始范围
 float minValue = 11f;
 float maxValue = 19.6f;

 /**
  * 0-准备计时 1-计时中 2-正常计步中
  */
 private int CountTimeState = 0;
 public static int TEMP_STEP = 0;
 private int lastStep = -1;
 //用x、y、z轴三个维度算出的平均值
 public static float average = 0;
 private Timer timer;
 // 倒计时3.5秒，3.5秒内不会显示计步，用于屏蔽细微波动
 private long duration = 3500;
 private TimeCount time;

 public StepSensorAcceleration(Context context, StepCallBack stepCallBack) {
  super(context, stepCallBack);
 }

 @Override
 protected void registerStepListener() {
  // 注册加速度传感器
  isAvailable = sensorManager.registerListener(this,
    sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER),
    SensorManager.SENSOR_DELAY_UI);
  if (isAvailable) {
   Log.i(TAG, "加速度传感器可用！");
  } else {
   Log.i(TAG, "加速度传感器不可用！");
  }
 }

 @Override
 public void unregisterStep() {
  sensorManager.unregisterListener(this);
 }

 public void onAccuracyChanged(Sensor arg0, int arg1) {
 }

 public void onSensorChanged(SensorEvent event) {
  Sensor sensor = event.sensor;
  synchronized (this) {
   if (sensor.getType() == Sensor.TYPE_ACCELEROMETER) {
    calc_step(event);
   }
  }
 }

 synchronized private void calc_step(SensorEvent event) {
  average = (float) Math.sqrt(Math.pow(event.values[0], 2)
    + Math.pow(event.values[1], 2) + Math.pow(event.values[2], 2));
  detectorNewStep(average);
 }

 /*
  * 检测步子，并开始计步
  * 1.传入sersor中的数据
  * 2.如果检测到了波峰，并且符合时间差以及阈值的条件，则判定为1步
  * 3.符合时间差条件，波峰波谷差值大于initialValue，则将该差值纳入阈值的计算中
  * */
 public void detectorNewStep(float values) {
  if (gravityOld == 0) {
   gravityOld = values;
  } else {
   if (DetectorPeak(values, gravityOld)) {
    timeOfLastPeak = timeOfThisPeak;
    timeOfNow = System.currentTimeMillis();

    if (timeOfNow - timeOfLastPeak >= 200
      && (peakOfWave - valleyOfWave >= ThreadValue) && (timeOfNow - timeOfLastPeak) <= 2000) {
     timeOfThisPeak = timeOfNow;
     //更新界面的处理，不涉及到算法
     preStep();
    }
    if (timeOfNow - timeOfLastPeak >= 200
      && (peakOfWave - valleyOfWave >= initialValue)) {
     timeOfThisPeak = timeOfNow;
     ThreadValue = Peak_Valley_Thread(peakOfWave - valleyOfWave);
    }
   }
  }
  gravityOld = values;
 }

 private void preStep() {
//  if (CountTimeState == 0) {
//   // 开启计时器
//   time = new TimeCount(duration, 700);
//   time.start();
//   CountTimeState = 1;
//   Log.v(TAG, "开启计时器");
//  } else if (CountTimeState == 1) {
//   TEMP_STEP++;
//   Log.v(TAG, "计步中 TEMP_STEP:" + TEMP_STEP);
//  } else if (CountTimeState == 2) {
  CURRENT_SETP++;
//   if (stepCallBack != null) {
  stepCallBack.Step(CURRENT_SETP);
//   }
//  }

 }


 /*
  * 检测波峰
  * 以下四个条件判断为波峰：
  * 1.目前点为下降的趋势：isDirectionUp为false
  * 2.之前的点为上升的趋势：lastStatus为true
  * 3.到波峰为止，持续上升大于等于2次
  * 4.波峰值大于1.2g,小于2g
  * 记录波谷值
  * 1.观察波形图，可以发现在出现步子的地方，波谷的下一个就是波峰，有比较明显的特征以及差值
  * 2.所以要记录每次的波谷值，为了和下次的波峰做对比
  * */
 public boolean DetectorPeak(float newValue, float oldValue) {
  lastStatus = isDirectionUp;
  if (newValue >= oldValue) {
   isDirectionUp = true;
   continueUpCount++;
  } else {
   continueUpFormerCount = continueUpCount;
   continueUpCount = 0;
   isDirectionUp = false;
  }

//  Log.v(TAG, "oldValue:" + oldValue);
  if (!isDirectionUp && lastStatus
    && (continueUpFormerCount >= 2 && (oldValue >= minValue && oldValue < maxValue))) {
   peakOfWave = oldValue;
   return true;
  } else if (!lastStatus && isDirectionUp) {
   valleyOfWave = oldValue;
   return false;
  } else {
   return false;
  }
 }

 /*
  * 阈值的计算
  * 1.通过波峰波谷的差值计算阈值
  * 2.记录4个值，存入tempValue[]数组中
  * 3.在将数组传入函数averageValue中计算阈值
  * */
 public float Peak_Valley_Thread(float value) {
  float tempThread = ThreadValue;
  if (tempCount < valueNum) {
   tempValue[tempCount] = value;
   tempCount++;
  } else {
   tempThread = averageValue(tempValue, valueNum);
   for (int i = 1; i < valueNum; i++) {
    tempValue[i - 1] = tempValue[i];
   }
   tempValue[valueNum - 1] = value;
  }
  return tempThread;

 }

 /*
  * 梯度化阈值
  * 1.计算数组的均值
  * 2.通过均值将阈值梯度化在一个范围里
  * */
 public float averageValue(float value[], int n) {
  float ave = 0;
  for (int i = 0; i < n; i++) {
   ave += value[i];
  }
  ave = ave / valueNum;
  if (ave >= 8) {
//   Log.v(TAG, "超过8");
   ave = (float) 4.3;
  } else if (ave >= 7 && ave < 8) {
//   Log.v(TAG, "7-8");
   ave = (float) 3.3;
  } else if (ave >= 4 && ave < 7) {
//   Log.v(TAG, "4-7");
   ave = (float) 2.3;
  } else if (ave >= 3 && ave < 4) {
//   Log.v(TAG, "3-4");
   ave = (float) 2.0;
  } else {
//   Log.v(TAG, "else");
   ave = (float) 1.7;
  }
  return ave;
 }

 class TimeCount extends CountDownTimer {
  public TimeCount(long millisInFuture, long countDownInterval) {
   super(millisInFuture, countDownInterval);
  }

  @Override
  public void onFinish() {
   // 如果计时器正常结束，则开始计步
   time.cancel();
   CURRENT_SETP += TEMP_STEP;
   lastStep = -1;
   Log.v(TAG, "计时正常结束");

   timer = new Timer(true);
   TimerTask task = new TimerTask() {
    public void run() {
     if (lastStep == CURRENT_SETP) {
      timer.cancel();
      CountTimeState = 0;
      lastStep = -1;
      TEMP_STEP = 0;
      Log.v(TAG, "停止计步：" + CURRENT_SETP);
     } else {
      lastStep = CURRENT_SETP;
     }
    }
   };
   timer.schedule(task, 0, 2000);
   CountTimeState = 2;
  }

  @Override
  public void onTick(long millisUntilFinished) {
   if (lastStep == TEMP_STEP) {
    Log.v(TAG, "onTick 计时停止:" + TEMP_STEP);
    time.cancel();
    CountTimeState = 0;
    lastStep = -1;
    TEMP_STEP = 0;
   } else {
    lastStep = TEMP_STEP;
   }
  }
 }
}