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->setMaximumBlockCount(10000);

    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"));