numberFormatButtons.addButton(ui->rbFloat,  NumberFormat_float);

    numberFormatButtons.addButton(ui->rbASCII,  NumberFormat_ASCII);

    QObject::connect(&numberFormatButtons, SIGNAL(buttonToggled(int, bool)),

                     this, SLOT(onNumberFormatButtonToggled(int, bool)));

    // init port signals

    QObject::connect(&(this->serialPort), SIGNAL(error(QSerialPort::SerialPortError)),

                     this, SLOT(onPortError(QSerialPort::SerialPortError)));

    // set limits for axis limit boxes

    ui->spYmin->setRange((-1) * std::numeric_limits<double>::max(),

                         std::numeric_limits<double>::max());

    ui->spYmax->setRange((-1) * std::numeric_limits<double>::max(),

                         std::numeric_limits<double>::max());

    // init data arrays and plot

    numOfSamples = ui->spNumOfSamples->value();

    numOfChannels = 1;

    dataX.resize(numOfSamples);

    for (int i = 0; i < dataX.size(); i++)

    {

        dataX[i] = i;

    }

    // init channel data and curve list

    for (unsigned int i = 0; i < numOfChannels; i++)

    {

        channelsData.append(DataArray(numOfSamples, 0.0));

        curves.append(new QwtPlotCurve());

        curves[i]->setSamples(dataX, channelsData[i]);

        curves[i]->setPen(makeColor(i));

        curves[i]->attach(ui->plot);

    }

    // init number format

    if (numberFormatButtons.checkedId() >= 0)

    {

        selectNumberFormat((NumberFormat) numberFormatButtons.checkedId());

    }

    else

    {

        selectNumberFormat(NumberFormat_uint8);

    }

    // init text view

    ui->ptTextView->setEnabled(ui->cbEnableTextView->isChecked());

    // TODO: does this work in binary mode? (no new lines)

    ui->ptTextView->setMaximumBlockCount(10000);

    QObject::connect(ui->cbEnableTextView, &QCheckBox::toggled,

                     ui->ptTextView, &QWidget::setEnabled);

    QObject::connect(ui->pbClearTextView, &QPushButton::clicked,

                     ui->ptTextView, &QPlainTextEdit::clear);

    // Init sps (sample per second) counter

    sampleCount = 0;

    spsLabel.setText("0sps");

    spsLabel.setToolTip("samples per second (total of all channels)");

    ui->statusBar->addPermanentWidget(&spsLabel);

    spsTimer.start(SPS_UPDATE_TIMEOUT * 1000);

    QObject::connect(&spsTimer, &QTimer::timeout,

                     this, &MainWindow::spsTimerTimeout);

    // Init demo mode

    demoCount = 0;

    demoTimer.setInterval(100);

    QObject::connect(&demoTimer, &QTimer::timeout,

                     this, &MainWindow::demoTimerTimeout);

    QObject::connect(ui->actionDemoMode, &QAction::toggled,

                     this, &MainWindow::enableDemo);

    {   // init demo indicator

        QwtText demoText(" DEMO RUNNING ");  // looks better with spaces

        demoText.setColor(QColor("white"));

        demoText.setBackgroundBrush(Qt::darkRed);

        demoText.setBorderRadius(4);

        demoText.setRenderFlags(Qt::AlignLeft | Qt::AlignTop);

        demoIndicator.setText(demoText);

        demoIndicator.hide();

        demoIndicator.attach(ui->plot);

    }

}

MainWindow::~MainWindow()

{

    for (auto curve : curves)

    {

        delete curve;

    }

    if (serialPort.isOpen())

    {

        serialPort.close();

    }

    delete ui;

}

void MainWindow::setupAboutDialog()

{

    Ui_AboutDialog uiAboutDialog;

    uiAboutDialog.setupUi(&aboutDialog);

            readSample = &MainWindow::readSampleAs<qint16>;

            break;

        case NumberFormat_uint32:

            sampleSize = 4;

            readSample = &MainWindow::readSampleAs<quint32>;

            break;

        case NumberFormat_int32:

            sampleSize = 4;

            readSample = &MainWindow::readSampleAs<qint32>;

            break;

        case NumberFormat_float:

            sampleSize = 4;

            readSample = &MainWindow::readSampleAs<float>;

            break;

        case NumberFormat_ASCII:

            sampleSize = 0;    // these two members should not be used

            readSample = NULL; // in this mode

            break;

    }

    if (numberFormat == NumberFormat_ASCII)

    {

        QObject::disconnect(&(this->serialPort), &QSerialPort::readyRead, 0, 0);

        QObject::connect(&(this->serialPort), &QSerialPort::readyRead,

                         this, &MainWindow::onDataReadyASCII);

        portControl.enableSkipByte();

    }

    else

    {

        QObject::disconnect(&(this->serialPort), &QSerialPort::readyRead, 0, 0);

        QObject::connect(&(this->serialPort), &QSerialPort::readyRead,

                         this, &MainWindow::onDataReady);

        portControl.enableSkipByte(false);

    }

}

template<typename T> double MainWindow::readSampleAs()

{

    T data;

    this->serialPort.read((char*) &data, sizeof(data));

    // print data in hex format

    if (ui->cbEnableTextView->isChecked())

    {

        QTextCursor cursor(ui->ptTextView->document());

        cursor.movePosition(QTextCursor::End);

        QByteArray ba((char*) &data, sizeof(data));

        cursor.insertText(ba.toHex() + " ");

    }

    if (ui->rbLittleE->isChecked())

    {

        data = qFromLittleEndian(data);

    }

    else

    {

        data = qFromBigEndian(data);

    }

    return double(data);

}

bool MainWindow::isDemoRunning()

{

    return ui->actionDemoMode->isChecked();

}

void MainWindow::spsTimerTimeout()

{

    spsLabel.setText(QString::number(sampleCount/SPS_UPDATE_TIMEOUT) + "sps");

    sampleCount = 0;

}

void MainWindow::demoTimerTimeout()

{

    demoCount++;

    if (demoCount > 100) demoCount = 0;

    if (!ui->actionPause->isChecked())

    {

        for (unsigned int ci = 0; ci < numOfChannels; ci++)

        {

            DataArray data(1);

            data.replace(0, (ci + 1)*demoCount);

            addChannelData(ci, data);

        }

    }

}

void MainWindow::enableDemo(bool enabled)

{

    if (enabled)

    {

        if (!serialPort.isOpen())

        {

            demoTimer.start();