aduino传数据分段问题

Question

最近写一个计步器，安卓上的蓝牙代码都写好了，但是遇到一个问题就是蓝牙数据分段，一句话就是一次接收到的数据不完整，然后我就想自己定义一个数据包，可是加速度模块产生的三轴数据有可能是正数或者负数，比如一组三轴数据可能为{-1.56，0.98，-1.23} 或者{1.22，0.56,-10.23},我现在就想请教各位前辈，怎么自己组织数据包，让后把数据用Serial.wirte()字节流的方式发送到手机端，在手机端对数据进行解析？

 SoftwareSerial BTserial(2,3);//模拟串口 2-tx  3-rx
unsigned char Re_buf[11],counter=0;
unsigned char sign=0;
float a[3],w[3],angle[3],T;//分别是加速度，角速度，角度，温度
float res ;
byte accelBuffer[5]; 
void setup() {
  Serial.begin(9600);//每隔50ms就从mpu6050模块读取一帧数据（加速度，角速度，角度，温度）
  BTserial.begin(9600);
  initBuffer();
}

void loop() { 
  translate();

}

void serialEvent() {//当串口缓冲区有数据时，才运行此函数。当启用该事件时，其实是在两次loop（）循环之间检测串口缓冲区中是否有数据，如果有则调用此函数。
  while (Serial.available()) {

    //char inChar = (char)Serial.read(); Serial.print(inChar); //输出原始数据Output Original Data, use this code 

    Re_buf[counter]=(unsigned char)Serial.read();
    if(counter==0 && Re_buf[0]!=0x55) return;      //第 0 号数据不是帧头，跳过�              
    counter++;       
    if(counter==11)             ///接收到 11 个数据�
    {    
       counter=0;  //重新赋值，准备下一帧数据的接收
       sign=1;
    }

  }
}
void translate() {
  if(sign)
  { 
     sign=0;
     if(Re_buf[0]==0x55)      //包头�
     {  
        switch(Re_buf [1])
        {
            case 0x51:
                  a[0] = (short(Re_buf [3]<<8| Re_buf [2]))/32768.0*16;
                  a[1] = (short(Re_buf [5]<<8| Re_buf [4]))/32768.0*16;
                  a[2] = (short(Re_buf [7]<<8| Re_buf [6]))/32768.0*16;
                  T = (short(Re_buf [9]<<8| Re_buf [8]))/340.0+36.25;
                  break;
            case 0x52:
                  w[0] = (short(Re_buf [3]<<8| Re_buf [2]))/32768.0*2000;
                  w[1] = (short(Re_buf [5]<<8| Re_buf [4]))/32768.0*2000;
                  w[2] = (short(Re_buf [7]<<8| Re_buf [6]))/32768.0*2000;
                  T = (short(Re_buf [9]<<8| Re_buf [8]))/340.0+36.25;
                  break;
            case 0x53:
                  angle[0] = (short(Re_buf [3]<<8| Re_buf [2]))/32768.0*180;
                  angle[1] = (short(Re_buf [5]<<8| Re_buf [4]))/32768.0*180;
                  angle[2] = (short(Re_buf [7]<<8| Re_buf [6]))/32768.0*180;
                  T = (short(Re_buf [9]<<8| Re_buf [8]))/340.0+36.25;

                 res = sqrt(sq(a[0]) + sq(a[1]) + sq(a[1]));
                 //BTserial.print(res);
                 //Serial.println(res);

                 initBuffer();
                 for (int j =1;j < 4;j++) {
                  accelBuffer[j] = (char)a[j-1];
                  //Serial.println(a[j-1]);
                  }
                  for (int j =0;j < 5;j++) {
                  //Serial.println(accelBuffer[j]);
                  }
                  //Serial.write((char*)accelBuffer);
                 BTserial.write((char *)accelBuffer);
                  break;
          } 
       }
    } 
}

void initBuffer() {
  for (int i=0;i < 5;i++ ) {
    accelBuffer[i] = 50                           ;
  }
  accelBuffer[0] = 0xfe;
  accelBuffer[4] = 0xff;
}

上面是我写的代码，但是感觉有问题，昨天才接触这个，好多问题都想不明白。请前辈们指教！

Answer 1

http://blog.csdn.net/kingda008/article/details/9668419