周期性任务（消息通过蓝牙发送）

Question

在我的移动机器人项目，该项目有2个伺服电机在两个平面旋转的相机，我想通过旋转来控制他们在我的Android应用程序的智能手机（通过读数偏航/俯仰/从智能手机的加速度计滚动）。

为此，我必须通过蓝牙向Arduino发送关于这三个角度的数据。因此，例如，样本数据分组的样子：

“Y：100，P：20，R：45” 其中[Y-偏航，P-间距，R辊。 >bl.sendData("A:"+String.format("%.0f",azimut) + ",P:" + String.format("%.0f",pitch) + ",R:" + String.format("%.0f",roll) + ".");

欲被在每200ms发送环状此消息（当我在此活动林） - - >（现在它是负责发送该命令/消息的Arduino

代码每次点击按钮“发送”：D时发送）。

我还必须提到的是，除了这个消息Arduino的应用程序发送另一个消息，当我触摸虚拟摇杆在这同样的活动来控制我的移动机器人的方向，我希望这是同时发送邮件）

之间没有冲突

那我该如何得到它？一些示例代码？

这是从Android Studio中的代码（这个活动）：

package com.samplecompass; 
import android.app.Activity; 
import android.bluetooth.BluetoothAdapter; 
import android.content.Context; 
import android.content.Intent; 
import android.graphics.Canvas; 
import android.graphics.Paint; 
import android.graphics.Paint.Style; 
import android.hardware.Sensor; 
import android.hardware.SensorEvent; 
import android.hardware.SensorEventListener; 
import android.hardware.SensorManager; 
import android.os.Bundle; 
import android.os.Handler; 
import android.util.Log; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 
import android.widget.Toast; 

public class MainActivity extends Activity implements SensorEventListener { 
    private cBluetooth bl = null; 
    private String address = "00:11:35:94:61:19"; 
    private StringBuilder sb = new StringBuilder(); 
    private Button send; 


    Float azimutF; 
    Float pitchF; 
    Float pitchMax=0.0f; 
    Float azimut; // View to draw a compass 
    Float pitch; 
    Float roll; 
    int zgoda=0; 
    int zgodaa=1; 
    int znak=1; 
    private TextView mPitch; 





    private SensorManager mSensorManager; 
    Sensor accelerometer; 
    Sensor magnetometer; 

    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     bl = new cBluetooth(this, mHandler); 
     bl.checkBTState(); 
     mPitch = (TextView) findViewById(R.id.Pitch); 
     send = (Button) findViewById(R.id.send); 

     mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE); 
     accelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER); 
     magnetometer = mSensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD); 


     send.setOnClickListener(new View.OnClickListener() { 

      @Override 
      public void onClick(View view) { 
       zgodaa=0; 
       //bl.sendData("Hello"); 
      } 
     }); 
    } 

    private final Handler mHandler = new Handler() { 
     public void handleMessage(android.os.Message msg) { 
      switch (msg.what) { 
       case cBluetooth.BL_NOT_AVAILABLE: 
        Log.d(cBluetooth.TAG, "Bluetooth is not available. Exit"); 
        Toast.makeText(getBaseContext(), "Bluetooth is not available", Toast.LENGTH_SHORT).show(); 
        finish(); 
        break; 
       case cBluetooth.BL_INCORRECT_ADDRESS: 
        Log.d(cBluetooth.TAG, "Incorrect MAC address"); 
        Toast.makeText(getBaseContext(), "Incorrect Bluetooth address", Toast.LENGTH_SHORT).show(); 
        break; 
       case cBluetooth.BL_REQUEST_ENABLE: 
        Log.d(cBluetooth.TAG, "Request Bluetooth Enable"); 
        BluetoothAdapter.getDefaultAdapter(); 
        Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); 
        startActivityForResult(enableBtIntent, 1); 
        break; 
       case cBluetooth.BL_SOCKET_FAILED: 
        Toast.makeText(getBaseContext(), "Socket failed", Toast.LENGTH_SHORT).show(); 
        finish(); 
        break; 
       case cBluetooth.RECIEVE_MESSAGE:             // if message is recieved 
        byte[] readBuf = (byte[]) msg.obj; 
        String strIncom = new String(readBuf, 0, msg.arg1);     // create string from bytes array 
        sb.append(strIncom);            // append string 
        int endOfLineIndex = sb.indexOf("\r\n");       // determine the end-of-line 
        if (endOfLineIndex > 0) {           // if end-of-line, 
         String sbprint = sb.substring(0, endOfLineIndex);    // extract string 
         sb.delete(0, sb.length());          // and clear 
         //txtArduino.setText("Data from Arduino: " + sbprint);   // update TextView 

        } 
        break; 
      } 
     }; 
    }; 

    protected void onResume() { 
     super.onResume(); 
     bl.BT_Connect(address); 
     //bl.sendData("Hello World"); 
     mSensorManager.registerListener(this, accelerometer, SensorManager.SENSOR_DELAY_UI); 
     mSensorManager.registerListener(this, magnetometer, SensorManager.SENSOR_DELAY_UI); 
    } 

    protected void onPause() { 
     super.onPause(); 
     bl.BT_onPause(); 
     mSensorManager.unregisterListener(this); 
    } 

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

    float[] mGravity; 
    float[] mGeomagnetic; 

    public void onSensorChanged(SensorEvent event) { 
     if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER) 
      mGravity = event.values; 
     if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD) 
      mGeomagnetic = event.values; 

     if (mGravity != null && mGeomagnetic != null) { 
      float R[] = new float[9]; 
      float I[] = new float[9]; 
      boolean success = SensorManager.getRotationMatrix(R, I, mGravity, mGeomagnetic); 
      if (success) { 
       float orientation[] = new float[3]; 
       SensorManager.getOrientation(R, orientation); 
       if(zgoda==0) { 
        azimutF = -orientation[0] * 360/(2 * 3.14159f) - 90; 
        pitchF = orientation[1]*360/(2*3.14159f); 
       } 
       zgoda=1; 
       azimut = -orientation[0]*360/(2*3.14159f) - azimutF; // orientation contains: azimut, pitch and roll 
       pitch = -1*(orientation[1]*360/(2*3.14159f)); 
       if(pitchMax<pitch){ pitchMax=pitch;} 

       /**if (Math.round(pitch) == 0) { 
        if(znak==1) znak=-1; 
        else if(znak==-1) znak=1; 
       }**/ 
       roll = -orientation[2]*360/(2*3.14159f); 
       mPitch.setText(String.valueOf("Azimut: " + String.format("%.0f",azimut)) + String.valueOf("Znak:" + pitchMax) + String.valueOf("Pitch:" + String.format("%.0f",pitch)) + String.valueOf("Roll:" + String.format("%.0f",roll))); 
       if(zgodaa== 0) {bl.sendData("A:"+String.format("%.0f",azimut) + ",P:" + String.format("%.0f",pitch) + ",R:" + String.format("%.0f",roll) + ".");} 
       zgodaa=1; 
      } 
     } 

    } 
} 

Answer 1

@jdv谢谢大家的帮助，现在我知道如何做到这一点 - >

public class MainActivity extends Activity implements SensorEventListener { 

    private Handler handler 
    ... 

    protected void onCreate(Bundle savedInstanceState) { 
    handler = new Handler();  
    ... 
    } 

    Runnable mStatusChecker = new Runnable() { 
     @Override 
     public void run() { 
      try { 
       bl.sendData("A:"+i+String.format("%.0f",azimut) + ",P:" + String.format("%.0f",pitch) + ",R:" + String.format("%.0f",roll) + ".");; //this function can change value of mInterval. 
      } finally { 
       // 100% guarantee that this always happens, even if 
       // your update method throws an exception 
       handler.postDelayed(mStatusChecker, 1000); 
      } 


     } 
    }; 

    void startRepeatingTask() { 
     mStatusChecker.run(); 
    } 

    void stopRepeatingTask() { 
     mHandler.removeCallbacks(mStatusChecker); 
    } 

    private final Handler mHandler = new Handler() { 
     public void handleMessage(android.os.Message msg) { 
      switch (msg.what) { 
       case cBluetooth.BL_OK: 
        startRepeatingTask(); 
        Toast.makeText(getBaseContext(), "BL_OK", 
        Toast.LENGTH_SHORT).show(); 
        break; 
           } 
       } 
} 

因此，我调用函数当蓝牙连接时，因为在其他情况下弹出错误。

但现在我有一个问题，我不希望创建新的话题，所以你可以告诉我哪个功能调用，当我把我的智能手机home键和后退按钮？

onResume在这两种情况下或万一HOME另一个功能？