QObject::connect(&tbPortList,

                     SELECT<int>::OVERLOAD_OF(&QComboBox::activated),

                     this, &PortControl::onTbPortListActivated);

    QObject::connect(ui->cbPortList,

                     SELECT<const QString&>::OVERLOAD_OF(&QComboBox::activated),

                     this, &PortControl::selectPort);

    // setup buttons

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

                     this, &PortControl::loadPortList);

    ui->pbOpenPort->setDefaultAction(&openAction);