diff --git a/main_window.cpp b/main_window.cpp
index ad4cba5..33d6669 100755
--- a/main_window.cpp
+++ b/main_window.cpp
@@ -11,6 +11,9 @@
 #include<QMessageBox>
 #include <cstdint>
 #include <QLineSeries>
+#include <QChart>
+#include <QChartView>
+#include <QWidget>
 
 static bool check_exist(QString str) {
     for (auto &port: QSerialPortInfo::availablePorts()) {
@@ -20,25 +23,67 @@ static bool check_exist(QString str) {
     return false;
 }
 
+void main_window::config_enable(bool ena) {
+    portsComboBox->setEnabled(ena);
+    stopbitsComboBox->setEnabled(ena);
+    baudLineEdit->setEnabled(ena);
+    dataBitsComboBox->setEnabled(ena);
+    tmpFilenameEdit->setEnabled(ena);
+    portUpdBtn->setEnabled(ena);
+    if (ena) {
+        portOpenBtn->setText("open"), is_open = false;
+        if (receivefile.isOpen())
+            receivefile.close();
+    }
+    else {
+        portOpenBtn->setText("close"), is_open = true;
+        auto filename = tmpFilenameEdit->text();
+        receivefile.setFileName(filename);
+        receivefile.open(QIODevice::Append);
+    }
+
+}
+
 void main_window::setUiComponent() {
     this->ui = new Ui::MainWindow;
     ui->setupUi(this);
     portsComboBox = ui->portsComboBox;
-    hexTextEdit = ui->hexTextEdit;
+    stopbitsComboBox = ui->stopbitsComboBox;
+    baudLineEdit = ui->baudLineEdit;
+    dataBitsComboBox = ui->dataBitsComboBox;
     tmpFilenameEdit = ui->tmpFilenameEdit;
+
+    hexTextEdit = ui->hexTextEdit;
+    asciiTextEdit = ui->asciiTextEdit;
     portOpenBtn = ui->portOpenBtn;
-    portsComboBox = ui->portsComboBox;
     portUpdBtn = ui->portUpdBtn;
     statusbar = ui->statusbar;
-    stopbitsComboBox = ui->stopbitsComboBox;
-    asciiTextEdit = ui->asciiTextEdit;
     QObject::connect(portOpenBtn, SIGNAL(clicked()), this, SLOT(open_port()));
     QObject::connect(portUpdBtn, SIGNAL(clicked()), this, SLOT(update_ui_port()));
 }
 
+void main_window::port_error_handler(QSerialPort::SerialPortError err) {
+    switch (err) {
+        case QSerialPort::NoError:
+            break;
+        case QSerialPort::DeviceNotFoundError:
+        case QSerialPort::PermissionError:
+        case QSerialPort::OpenError:
+        case QSerialPort::WriteError:
+        case QSerialPort::ReadError:
+        case QSerialPort::ResourceError:
+        case QSerialPort::UnsupportedOperationError:
+        case QSerialPort::UnknownError:
+        case QSerialPort::TimeoutError:
+        case QSerialPort::NotOpenError:
+            this->config_enable(true);
+    }
+}
+
 main_window::main_window(QWidget *parent) : QMainWindow(parent) {
     setUiComponent();
     QObject::connect(&port, SIGNAL(readyRead()), this, SLOT(read_data()));
+    QObject::connect(&port, &QSerialPort::errorOccurred, this, &main_window::port_error_handler);
     QFont font("Courier");
     hexTextEdit->setFont(font);
     QSerialPortInfo info;
@@ -67,19 +112,11 @@ void main_window::update_ui_port() {
 }
 
 void main_window::open_port() {
-    if (is_open) {
+    if (port.isOpen()) {
         port.close();
-        QFile file;
-        auto filename = tmpFilenameEdit->text();
-        file.setFileName(filename);
-        file.open(QIODevice::Append);
-        auto val = hexTextEdit->toPlainText();
-        hexTextEdit->clear();
-        file.write(val.toUtf8());
-        file.close();
-        is_open = false;
-        portOpenBtn->setText("open");
-        return;
+        config_enable(true);
+        statusbar->showMessage("close port success");
+        return ;
     }
     if (portsComboBox->count() == 0) { return; }
     auto cur_port = portsComboBox->currentText();
@@ -90,23 +127,21 @@ void main_window::open_port() {
     else if (stopbits == QString("1.5")) port.setStopBits(QSerialPort::OneAndHalfStop);
     else if (stopbits == QString("2")) port.setStopBits(QSerialPort::TwoStop);
     else {
-        QMessageBox box;
-        box.setText("wrong stopbits settings");
-        box.exec();
+        box.setText("wrong stopbits settings"), box.exec();
         return;
     }
-
     // TODO: read info from config
     port.setBaudRate(115200);
     port.setDataBits(QSerialPort::Data8);
     port.setParity(QSerialPort::NoParity);
     port.setFlowControl(QSerialPort::NoFlowControl);
     if (port.open(QIODevice::ReadWrite)) {
-        is_open = true;
-        portOpenBtn->setText("close");
+
+        config_enable(false);
         statusbar->showMessage("open port success");
-    } else
-        is_open = false;
+    } else {
+        config_enable(true);
+    }
 
 }
 
@@ -124,23 +159,14 @@ void main_window::read_data() {
     QString new_text = QString(data.toHex(' ').toUpper()) + " ";
     hexTextEdit->moveCursor(QTextCursor::End);
     hexTextEdit->insertPlainText(new_text);
-    if (cnt > 1e3) {
-        QFile file;
-        auto filename = tmpFilenameEdit->text();
-        file.setFileName(filename);
-        file.open(QIODevice::Append);
-        auto val = hexTextEdit->toPlainText();
+    auto val = hexTextEdit->toPlainText();
+    receivefile.write(val.toUtf8());
+    if (hexTextEdit->toPlainText().length() > 1e3){
         hexTextEdit->clear();
         asciiTextEdit->clear();
-        file.write(val.toUtf8());
-        file.close();
-        cnt = 0;
     }
 }
 
-#include <QChart>
-#include <QChartView>
-#include <QWidget>
 
 void main_window::update_chart() {
     // TODO: memory leakage
diff --git a/main_window.h b/main_window.h
index 5b5e5b5..9073319 100755
--- a/main_window.h
+++ b/main_window.h
@@ -7,7 +7,9 @@
 
 #include "ui_main.h"
 #include <QSerialPort>
+#include <QFile>
 #include <QThread>
+#include <QMessageBox>
 
 class main_window : public QMainWindow {
 Q_OBJECT
@@ -20,6 +22,7 @@ private:
     Ui::MainWindow *ui;
     bool is_open = false;
     QSerialPort port;
+    QFile receivefile;
 
     QWidget *centralwidget;
     QHBoxLayout *horizontalLayout;
@@ -43,6 +46,8 @@ private:
     QMenuBar *menubar;
     QStatusBar *statusbar;
 
+    QMessageBox box;
+
 private:
     void setUiComponent();
 
@@ -56,6 +61,10 @@ public slots:
 
     void update_chart();
 
+
+    void port_error_handler(QSerialPort::SerialPortError err);
+
+    void config_enable(bool ena);
 };