diff --git a/main_window.cpp b/main_window.cpp
index f7497d0..1531c86 100755
--- a/main_window.cpp
+++ b/main_window.cpp
@@ -18,6 +18,9 @@ static bool check_exist(QString str) {
     return false;
 }
 
+QTextStream receivefileStream;
+
+
 void main_window::config_enable(bool ena) {
     portsComboBox->setEnabled(ena);
     stopbitsComboBox->setEnabled(ena);
@@ -29,11 +32,18 @@ void main_window::config_enable(bool ena) {
         portOpenBtn->setText("open"), is_open = false;
         if (receivefile.isOpen())
             receivefile.close();
+        if (rawDataFile.isOpen())
+            rawDataFile.close();
     } else {
         portOpenBtn->setText("close"), is_open = true;
         auto filename = tmpFilenameEdit->text();
         receivefile.setFileName(filename);
         receivefile.open(QIODevice::Append);
+        receivefileStream.setDevice(&receivefile);
+        rawDataFile.setFileName(filename + "raw");
+        rawDataFile.open(QIODevice::Append);
+
+
     }
 
 }
@@ -174,61 +184,78 @@ void main_window::open_port() {
 }
 
 
-static uint64_t rest = 0;
 static int cnt = 0;
-static long long line_cnt = 0;
-QByteArray zero_finder;
-int zero_pos = -1;
-int buf_cnt = 0;
-int receive_cnt = 0;
+QByteArray first_frame;
+bool first = true;
+
 
 void main_window::read_data() {
-    auto data = port.readAll();
+    static int receive_num_cnt = 0;
+    static int receive_byte_cnt = 0;
     static int val = 0;
-    if (zero_pos == -1) {
-        if (zero_finder.size() < 10)
-            zero_finder += data;
-        if (zero_finder.size() < 10) {
+    auto data = port.readAll();
+    if (first) {
+        if (data.length() < 10) {
+            first_frame += data;
             return;
         }
+        while (first_frame[0] != 0) {
+            first_frame.remove(0, 1);
+        }
         int zero_cnt = 0;
-        for (int i = 0; i < 4; i++) {
-            if (zero_finder[i] == 0) {
-                zero_cnt++;
-                zero_pos = i;
+        do {
+            zero_cnt = 0;
+            while (first_frame[0] != 0) {
+                first_frame.remove(0, 1);
             }
-        }
-        for (int i = 4; i < zero_finder.size(); i++) {
-            if (zero_cnt == 1) {
-                break;
+
+            for (int i = 0; i < 4; i++) {
+                zero_cnt += first_frame[i] == 0 ? 1 : 0;
             }
-            if (zero_finder[i - 4] == 0)
-                zero_cnt--;
-            if (zero_finder[i] == 0) {
-                zero_cnt++;
-                zero_pos = i;
-            }
-        }
-
-        for (int i = zero_pos+1; i < zero_finder.size(); i++) {
-
-
-        }
+            first_frame.remove(0, 1);
+        } while (zero_cnt != 0);
+        data = first_frame;
+        first = false;
+    }
+    rawDataFile.write(data);
+    for (int i = 0; i < data.size(); i++) {
+        if (receive_byte_cnt % 4 == 0) {
+            if (data[i] != 0) {
+                // TODO: raise error
+                return;
+            }
+            receive_num_cnt++;
+            int real_number = val;
+            if (real_number & 0x800000) {
+                // negtive number
+                real_number = -(~real_number & 0x7fffff + 1);
+            }
+            receivefileStream << real_number << " ";
+            double scaled = (double) real_number / (double) (0x7fffff) * 2.5;
+            lineChart.data->append((double) receive_byte_cnt / 1000.0, scaled);
+            while (lineChart.data->count() > 5000) {
+                // data more than 5000 second, remove first data
+                lineChart.data->remove(0);
+            }
+            val = 0;
+            continue;
+        }
+        val <<= 8;
+        val |= data[i];
+        receive_byte_cnt++;
     }
-
-
-    asciiTextEdit->append(QString(data));
-    cnt += data.size();
     QString new_text = QString(data.toHex(' ').toUpper()) + " ";
     hexTextEdit->moveCursor(QTextCursor::End);
     hexTextEdit->insertPlainText(new_text);
-    auto val = hexTextEdit->toPlainText();
-    receivefile.write(val.toUtf8());
-    if (hexTextEdit->toPlainText().length() > 1e3) {
-        hexTextEdit->clear();
-        asciiTextEdit->clear();
+    auto tmp = hexTextEdit->toPlainText();
+    if (tmp.length() > 1e3) {
+        hexTextEdit->setPlainText(tmp.last((int) 1e3));
+        hexTextEdit->moveCursor(QTextCursor::End);
+    }
+    tmp = asciiTextEdit->toPlainText();
+    if (tmp.length() > 1e3) {
+        asciiTextEdit->setPlainText(tmp.last(int(1e3)));
+        asciiTextEdit->moveCursor(QTextCursor::End);
     }
-    lineChart.data->append(0, 0.5);
-    lineChart.data->append(0.5, 1);
 }
 
diff --git a/main_window.h b/main_window.h
index 5a0b462..b4b7923 100755
--- a/main_window.h
+++ b/main_window.h
@@ -39,6 +39,7 @@ private:
     bool is_open = false;
     QSerialPort port;
     QFile receivefile;
+    QFile rawDataFile;
 
     QWidget *centralwidget;
     QHBoxLayout *horizontalLayout;
@@ -64,8 +65,6 @@ private:
     QChartView *plotChartView;
 
     QMessageBox box;
-//    QChart* chart;
-//    QLineSeries* linedata;
     GLineChart lineChart;
 
 private: