CAN Bus Manager

范例发送/接收 CAN Bus 帧。

范例发送/接收 CAN Bus 帧。传入帧根据其类型进行排序。提供调节 CAN Bus 连接参数的连接对话框。

Key Qt Serial Bus 类被用于此范例：

Creating a QCanBusDevice

实例化的 QCanBusDevice is required to perform any CAN communication.

The ConnectDialog allows to specify all the required parameters. After that the device is created using the provided plugin and interface names:

    QString errorString;
    m_canDevice.reset(QCanBus::instance()->createDevice(p.pluginName, p.deviceInterfaceName,
                                                        &errorString));
    connect(m_canDevice.get(), &QCanBusDevice::errorOccurred,
            this, &MainWindow::processErrors);
    connect(m_canDevice.get(), &QCanBusDevice::framesReceived,
            this, &MainWindow::processReceivedFrames);
    connect(m_canDevice.get(), &QCanBusDevice::framesWritten,
            this, &MainWindow::processFramesWritten);

The established connections allow to process incoming frames, control the sent frames and handle errors.

When the device is created, use QCanBusDevice::connectDevice () to start the communication.

Processing Incoming Frames

QCanBusDevice 发射 framesReceived () signal when new frames are available. The readFrame () method can be used to read a single QCanBusFrame while there are available frames . Once the frame is received, individual parameters such as frameId , timeStamp ，或 payload can be extracted from it:

    while (m_canDevice->framesAvailable()) {
        m_numberFramesReceived++;
        const QCanBusFrame frame = m_canDevice->readFrame();
        QString data;
        if (frame.frameType() == QCanBusFrame::ErrorFrame)
            data = m_canDevice->interpretErrorFrame(frame);
        else
            data = QString::fromLatin1(frame.payload().toHex(' ').toUpper());
        const QString time = QString::fromLatin1("%1.%2  ")
                .arg(frame.timeStamp().seconds(), 10, 10, ' '_L1)
                .arg(frame.timeStamp().microSeconds() / 100, 4, 10, '0'_L1);
        const QString flags = frameFlags(frame);
        const QString id = QString::number(frame.frameId(), 16).toUpper();
        const QString dlc = QString::number(frame.payload().size());
        m_model->appendFrame(QStringList({QString::number(m_numberFramesReceived),
                                          time, flags, id, dlc, data}));
    }

发送帧

To send custom data over the CAN bus, the user needs to provide at least a frameId 和 payload . Optionally other QCanBusFrame parameters can be configured:

    const uint frameId = m_ui->frameIdEdit->text().toUInt(nullptr, 16);
    QString data = m_ui->payloadEdit->text();
    m_ui->payloadEdit->setText(formatHexData(data));
    const QByteArray payload = QByteArray::fromHex(data.remove(u' ').toLatin1());
    QCanBusFrame frame = QCanBusFrame(frameId, payload);
    frame.setExtendedFrameFormat(m_ui->extendedFormatBox->isChecked());
    frame.setFlexibleDataRateFormat(m_ui->flexibleDataRateBox->isChecked());
    frame.setBitrateSwitch(m_ui->bitrateSwitchBox->isChecked());
    if (m_ui->errorFrame->isChecked())
        frame.setFrameType(QCanBusFrame::ErrorFrame);
    else if (m_ui->remoteFrame->isChecked())
        frame.setFrameType(QCanBusFrame::RemoteRequestFrame);

Once the frame is prepared, the QCanBusDevice::writeFrame () method can be used to send it:

    m_canDevice->writeFrame(frame);

运行范例

要运行范例从 Qt Creator ，打开 Welcome 模式，然后选择范例从 Examples 。更多信息，拜访构建和运行范例 .

范例工程 @ code.qt.io