Question

我正在开发一个项目，我从串口接收数据。数据正在从Arduino Mega ADK生成和发送。 arduino数据以字符“S”，“N”，“P”开头，用于标识数据包的开头。接下来是18个字节的数据，存储在9个quint16变量中。接下来是3个字节存储在quint8值中，接着是20个字节存储在4个int32值中。

我在将数据作为字符串发送时有这个工作，但我似乎无法找到一种方法来使数据作为单独的字节发送，并将它们重建为它们的值。

从我的阅读中，Arduino是小端，所以我按照以下方式在接收端构造值：

解析数据的函数在这里：

void MainWindow::NoseAviByte()
{
//Get data from nose cone avi bay
readNoseConeAvi();

//Look for SNP packet header
int curCount = 0;
int maxCount = dataBytes.size();


//Loop through array of bytes
while(curCount < maxCount)
{

    //If packet header is found, parse data vals
    if(((dataBytes.at(curCount) == 'S') && (dataBytes.at(curCount + 1) == 'N') && (dataBytes.at(curCount + 2) == 'P')) && (curCount + 62) < maxCount)
    {
        //All incoming values should be in little endian order
        curCount += 3;
        /***Start Low-g MEMS MPU-9250***/
        quint16 accX = 0;
        quint16 accY = 0;
        quint16 accZ = 0;
        quint16 gyroX = 0;
        quint16 gyroY = 0;
        quint16 gyroZ = 0;
        quint16 magX = 0;
        quint16 magY = 0;
        quint16 magZ = 0;
        /***End Low-g MEMS MPU-9250***/

        /***Start High-g ACC***/
        quint8 accHX = 0;
        quint8 accHY = 0;
        quint8 accHZ = 0;
        /***End High-g ACC***/

        /***Start Hgh precision Alt***/
        quint32 highPresAlt = 0;
        /***End Hgh precision Alt***/

         /***Start GPS***/
        quint32 gpsLat = 0;
        quint32 gpsLong = 0;
        quint32 gpsAlt = 0;
        quint32 gpsTime = 0;

        accX = (dataBytes.at(curCount) + (dataBytes.at(curCount + 1) << 8));
        curCount += 2;
        accY = (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8));
        curCount += 2;
        accZ = (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8));
        curCount += 2;
        gyroX = (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8));
        curCount += 2;
        gyroY = (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8));
        curCount += 2;
        gyroZ = (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8));
        curCount += 2;
        magX = (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8));
        curCount += 2;
        magY = (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8));
        curCount += 2;
        magZ = (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8));
        curCount += 2;

        accHX = dataBytes.at(curCount);
        curCount += 1;
        accHY = dataBytes.at(curCount);
        curCount += 1;
        accHZ = dataBytes.at(curCount);
        curCount += 1;

        highPresAlt = (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8) | (dataBytes.at(curCount + 2) << 16 ) | (dataBytes.at(curCount + 3) << 24));
        curCount += 4;

        gpsLat =  (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8) | (dataBytes.at(curCount + 2) << 16 ) | (dataBytes.at(curCount + 3) << 24));
        curCount += 4;
        gpsLong =  (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8) | (dataBytes.at(curCount + 2) << 16 ) | (dataBytes.at(curCount + 3) << 24));
        curCount += 4;
        gpsAlt =  (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8) | (dataBytes.at(curCount + 2) << 16 ) | (dataBytes.at(curCount + 3) << 24));
        curCount += 4;
        gpsTime =  (dataBytes.at(curCount) | (dataBytes.at(curCount + 1) << 8) | (dataBytes.at(curCount + 2) << 16 ) | (dataBytes.at(curCount + 3) << 24));
        curCount += 4;
    }
    else
    {
        curCount++;
    }
}

}

填充QByteArray的函数是：

void MainWindow::readNoseConeAvi()
{
QByteArray noseData = serial->readAll();
QDataStream stream(noseData);
dataBytes = noseData;
inDataStream = &stream;

qDebug() << "Reading data bytes from telemetry source: ";
}

我开始制作电子表格来跟踪任何不良值，并立即发现问题。看来我在重新组装32位值时做错了，但无法弄清楚原因。这是输出：

Answer 1

问题是，QByteArray::at()返回的char可能会消极。在将char添加到quint8之前，先将其转换为quint32 myValue = quint8(dataBytes.at(curCount)) | quint8(dataBytes.at(curCount+1)) << 8 | quint8(dataBytes.at(curCount+2)) << 16 | quint8(dataBytes.at(curCount+3)) << 24;。

quint32

这意味着您的所有转化都可能出错，而不仅仅是quint8。请务必在其他转化中指定Tools>Refresh类型。

我建议你创建转换功能，这样你就不必一遍又一遍地写出来。

错误重新组合字节以生成quint32值

1 个答案: