Renamed Release button to motors off

Added flow control

mainwindow.cpp

@@ -259,6 +259,8 @@ void MainWindow::serialconnect()
                 break;
             }
 
+            printer.setFlowControl(QSerialPort::HardwareControl);
+
             ui->connectBtn->setText("Disconnect");
             ui->sendBtn->setDisabled(false);
             //ui->pauseBtn->setDisabled(false);

mainwindow.ui

@@ -193,7 +193,7 @@
        <item row="3" column="3" colspan="4">
         <widget class="QPushButton" name="releasebtn">
          <property name="text">
-          <string>Release</string>
+          <string>Motors off</string>
          </property>
         </widget>
        </item>