一、准备工作

1.首先GY-39模块：GY-39技术参数

二、GY-39数据处理

1.数据解析

//根据通讯协议进行数据解析
int ClassGY39::parseSerialData(QByteArray qbaSerialData)

{

    unsigned char *cData = (unsigned char *)qbaSerialData.data();

    int nIllumi = (cData[4] << 24) + (cData[5] << 16) + (cData[6] << 8) + cData[7];

    float fTemp = ((qbaSerialData[13] << 8) + cData[14]) / 100.0;

    float fPre = ((cData[15] << 24) + (cData[16] << 16) + (cData[17] << 8) + cData[18]) / 100.0 / 1000.0;

    int nHum = ((cData[19] << 8) + cData[20]) / 100.0;

    int nAlti = (qbaSerialData[21] << 8) + cData[22];

    int flag = 0;

    flag += setIllumination(nIllumi);

    flag += setTemperature(fTemp);

    flag += setPressure(fPre);

    flag += setHumidity(nHum);

    flag += setAltitude(nAlti);

    return flag;

}

2.数据完整性校验

int ClassGY39::verifySerialData(QByteArray qbaSerialData)

{ 
   unsigned int nSum = 0;
    //校验光照强度数据包
    foreach (char cTmp, qbaSerialData.left(8)) //累加求和
    {
        nSum += cTmp;
    }
    //判断求和结果和校验位是否相同
    if ((nSum % 256) != (unsigned char)qbaSerialData.at(8))
    { 
       return -1; //不相同返回-1
    }
    //校验温度湿度数据包 
   nSum = 0;
    foreach (char cTmp, qbaSerialData.right(15).left(14))
    {   
     nSum += cTmp;   
 }  
  if ((nSum % 256) != (unsigned char)qbaSerialData.at(23))    
{    
    return -2; //不相同返回-2    
} 
   return 0;
}

3.数据处理

int ClassGY39::readSerialData(QSerialPort *serialPort)

{

    QByteArray qbaWeatherData = serialPort->readAll();

    if (qbaWeatherData.length() % 24 != 0 || qbaWeatherData.length() == 0) //检查数据长度

    {

        return -1; //数据长度不正确

    }

    qbaWeatherData = qbaWeatherData.right(24); //取最后一组数据

    if (verifySerialData(qbaWeatherData) != 0)

    {

        return -2; //数据校验错误

    }

    if (parseSerialData(qbaWeatherData) != 0)

    {

        return -3; //数据解析错误

    }

    return 0;

}