CAN 总线管理器

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：

• QCanBusDevice
• QCanBusFrame

创建 QCanBusDevice

实例化的 QCanBusDevice 被要求履行任何 CAN 通信。

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.

处理传入帧

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 欢迎 模式，然后选择范例从 范例 。更多信息，拜访 构建和运行范例 .

范例工程 @ code.qt.io

内容

• 创建 QCanBusDevice

• 处理传入帧

• 发送帧

• 运行范例