优化串口模块

app/src/main/java/cn/minbb/serial/activities/MainActivity.java

@@ -81,7 +81,7 @@ public class MainActivity extends AppCompatActivity {
     public void onClick(View view) {
         switch (view.getId()) {
             case R.id.open_serial_port:
-                if (serialPortManager.openSerialPort()) {
+                if (serialPortManager.openDefaultSerialPort()) {
                     Toast.makeText(getApplicationContext(), "串口打开成功", Toast.LENGTH_SHORT).show();
                     openSerial.setEnabled(false);
                     closeSerial.setEnabled(true);