diff --git a/app/src/main/java/me/f1reking/android_serialport/MainActivity.java b/app/src/main/java/me/f1reking/android_serialport/MainActivity.java
index 5c13fdb..2d4ef3c 100644
--- a/app/src/main/java/me/f1reking/android_serialport/MainActivity.java
+++ b/app/src/main/java/me/f1reking/android_serialport/MainActivity.java
@@ -73,7 +73,13 @@ public void onClick(View view) {
 
     private void open() {
         if (mSerialPortHelper == null) {
-            mSerialPortHelper = new SerialPortHelper.Builder("/dev/ttyUSB0", BAUDRATE.getBaudrate(BAUDRATE.B115200)).setStopBits(STOPB.getStopBit(STOPB.B2)).setDataBits(DATAB.getDataBit(DATAB.CS8)).setParity(PARITY.getParity(PARITY.NONE)).setFlowCon(FLOWCON.getFlowCon(FLOWCON.NONE)).build();
+            mSerialPortHelper = new SerialPortHelper();
+            mSerialPortHelper.setPort("/dev/ttyUSB0");
+            mSerialPortHelper.setBaudRate(BAUDRATE.getBaudrate(BAUDRATE.B115200));
+            mSerialPortHelper.setStopBits(STOPB.getStopBit(STOPB.B2));
+            mSerialPortHelper.setDataBits(DATAB.getDataBit(DATAB.CS8));
+            mSerialPortHelper.setParity(PARITY.getParity(PARITY.NONE));
+            mSerialPortHelper.setFlowCon(FLOWCON.getFlowCon(FLOWCON.NONE));
         }
         mSerialPortHelper.setIOpenSerialPortListener(new IOpenSerialPortListener() {
             @Override
diff --git a/serialportlib/src/main/java/me/f1reking/serialportlib/SerialPortHelper.java b/serialportlib/src/main/java/me/f1reking/serialportlib/SerialPortHelper.java
index fcbff9e..dc8dadf 100644
--- a/serialportlib/src/main/java/me/f1reking/serialportlib/SerialPortHelper.java
+++ b/serialportlib/src/main/java/me/f1reking/serialportlib/SerialPortHelper.java
@@ -57,13 +57,14 @@ public class SerialPortHelper {
     private SerialPortReceivedThread mSerialPortReceivedThread;
     private SerialPortFinder mSerialPortFinder;
 
-    private String mPort = "/dev/ttyUSB0"; //串口设置默认值
+    private static String mPort = "/dev/ttyUSB0"; //串口设置默认值
     private static int mBaudRate = 115200; //波特率默认值
     private static int mStopBits = 2; //停止位默认值
     private static int mDataBits = 8; //数据位默认值
     private static int mParity = 0; //校验位默认值
     private static int mFlowCon = 0; //流控默认值
     private static int mFlags = 0;
+    private boolean isOpen = false; //是否打开串口标志
 
     /**
      * 获得所有串口设备的地址
@@ -103,10 +104,94 @@ public boolean open() {
      */
     public void close() {
         closeSerialPort();
+        isOpen = false;
+    }
+
+    public boolean setPort(String port) {
+        if (isOpen) {
+            return false;
+        }
+        mPort = port;
+        return true;
+    }
+
+    public String getPort() {
+        return mPort;
+    }
+
+    public boolean setBaudRate(int baudRate) {
+        if (isOpen) {
+            return false;
+        }
+        mBaudRate = baudRate;
+        return true;
+    }
+
+    public int getBaudRate() {
+        return mBaudRate;
+    }
+
+    public boolean setDataBits(int dataBits) {
+        if (isOpen) {
+            return false;
+        }
+        mDataBits = dataBits;
+        return true;
+    }
+
+    public int getDataBits() {
+        return mDataBits;
+    }
+
+    public boolean setStopBits(int stopBits) {
+        if (isOpen) {
+            return false;
+        }
+        mStopBits = stopBits;
+        return true;
+    }
+
+    public int getStopBits() {
+        return mStopBits;
+    }
+
+    public boolean setParity(int parity) {
+        if (isOpen) {
+            return false;
+        }
+        mParity = parity;
+        return true;
+    }
+
+    public int getParity() {
+        return mParity;
+    }
+
+    public boolean setFlowCon(int flowCon) {
+        if (isOpen) {
+            return false;
+        }
+        mFlowCon = flowCon;
+        return true;
+    }
+
+    public int getFlowCon() {
+        return mFlowCon;
+    }
+
+    public boolean setFlags(int flags) {
+        if (isOpen) {
+            return false;
+        }
+        mFlags = flags;
+        return true;
+    }
+
+    public int getFlags() {
+        return mFlags;
     }
 
     public static class Builder {
-        private String mPort = "/dev/ttyUSB0"; //串口设置默认值
 
         public Builder(String port, int baudRate) {
             mPort = port;
@@ -225,6 +310,7 @@ private boolean openSerialPort(File device, int baudRate, int stopBits, int data
                 if (null != mIOpenSerialPortListener) {
                     mIOpenSerialPortListener.onFail(device, IOpenSerialPortListener.Status.NO_READ_WRITE_PERMISSION);
                 }
+                isOpen = false;
                 return false;
             }
         }
@@ -239,6 +325,7 @@ private boolean openSerialPort(File device, int baudRate, int stopBits, int data
             }
             startSendThread();
             startReceivedThread();
+            isOpen = true;
             return true;
         } catch (Exception e) {
             e.printStackTrace();
@@ -246,6 +333,7 @@ private boolean openSerialPort(File device, int baudRate, int stopBits, int data
                 mIOpenSerialPortListener.onFail(device, IOpenSerialPortListener.Status.OPEN_FAIL);
             }
         }
+        isOpen = false;
         return false;
     }