给我写个qt串口 mewtocol协议

好的，下面是一个基于Qt串口库的Mewtocol通信协议的示例代码：

#include <QSerialPort>
#include <QSerialPortInfo>

class MewtocolProtocol : public QObject
{
    Q_OBJECT

public:
    explicit MewtocolProtocol(QObject *parent = nullptr);

    bool connect(QString portName, qint32 baudRate);
    void disconnect();

    void sendCommand(quint8 cmd, const QByteArray &data = QByteArray());

signals:
    void dataReceived(quint8 cmd, const QByteArray &data);

private slots:
    void onReadyRead();

private:
    QSerialPort m_serialPort;
    QByteArray m_rxBuffer;
};

MewtocolProtocol::MewtocolProtocol(QObject *parent) : QObject(parent)
{
    connect(&m_serialPort, &QSerialPort::readyRead, this, &MewtocolProtocol::onReadyRead);
}

bool MewtocolProtocol::connect(QString portName, qint32 baudRate)
{
    m_serialPort.setPortName(portName);
    m_serialPort.setBaudRate(baudRate);
    m_serialPort.setDataBits(QSerialPort::Data8);
    m_serialPort.setParity(QSerialPort::NoParity);
    m_serialPort.setStopBits(QSerialPort::OneStop);
    m_serialPort.setFlowControl(QSerialPort::NoFlowControl);

    if (!m_serialPort.open(QIODevice::ReadWrite)) {
        qDebug() << "Failed to open serial port:" << m_serialPort.errorString();
        return false;
    }

    return true;
}

void MewtocolProtocol::disconnect()
{
    m_serialPort.close();
}

void MewtocolProtocol::sendCommand(quint8 cmd, const QByteArray &data)
{
    QByteArray txData;
    txData.append(cmd);
    txData.append(data);
    m_serialPort.write(txData);
}

void MewtocolProtocol::onReadyRead()
{
    m_rxBuffer.append(m_serialPort.readAll());

    while (m_rxBuffer.size() >= 2) {
        // Check if the received data starts with the command byte
        if (m_rxBuffer.at(0) != COMMAND_BYTE) {
            m_rxBuffer.remove(0, 1);
            continue;
        }

        // Get the data length byte
        quint8 dataLen = static_cast<quint8>(m_rxBuffer.at(1));

        // Wait until the full packet is received
        if (m_rxBuffer.size() < 2 + dataLen) {
            break;
        }

        // Extract the command and data bytes
        quint8 cmd = static_cast<quint8>(m_rxBuffer.at(0));
        QByteArray data = m_rxBuffer.mid(2, dataLen);

        // Emit the dataReceived signal
        emit dataReceived(cmd, data);

        // Remove the received packet from the buffer
        m_rxBuffer.remove(0, 2 + dataLen);
    }
}

这是一个基本的Mewtocol通信协议的实现，它使用Qt的串口库与外部设备进行通信。您需要根据实际情况进行修改，例如更改串口的参数，添加数据校验等。