diff --git a/.vscode/settings.json b/.vscode/settings.json
index ab5f439..a853f5b 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,5 +1,6 @@
 {
     "files.associations": {
-        "serial.h": "c"
+        "serial.h": "c",
+        "steering_gear.h": "c"
     }
 }
\ No newline at end of file
diff --git a/app/a.exe b/app/a.exe
index fcc6dcb..5b570f6 100644
Binary files a/app/a.exe and b/app/a.exe differ
diff --git a/app/main.c b/app/main.c
index 5aef6bb..24505cd 100644
--- a/app/main.c
+++ b/app/main.c
@@ -3,25 +3,11 @@
 #include <windows.h>
 
 #include "serial.h"
+#include "steering_gear.h"
 
-int serial_com_id;
+PORT serial_port;
+int  serial_com_id;
 
-int serial_test() {
-  PORT COM1;
-  char buff[1024] = {0};
-  int  rcv_len    = 0;
-
-  printf("Start open com%d\n", serial_com_id);
-  COM1 = serial_init(serial_com_id, 115200, 8, 1, 0);
-
-  while (1) {
-    Serial_SendData(COM1, "hello finny", 12);
-    memset(buff, 0, 1024);
-    rcv_len = Serial_ReciveData(COM1, buff, 1024);
-    printf("rcv:%s\n", buff);
-    Sleep(1);
-  }
-}
 int main(int argc, char *argv[]) {
   /* 参数判断 */
   if (argc != 2) {
@@ -32,14 +18,17 @@ int main(int argc, char *argv[]) {
 
   /* 字符串转int类型 */
   serial_com_id = atoi(argv[1]);
-  if (serial_com_id == 0) {/*  */
+  if (serial_com_id == 0) { /*  */
     /* 转换错误 */
     printf("The serial port id is incorrect\n");
     return -2;
   }
 
-  serial_test();
+  serial_port = serial_init(serial_com_id, 115200, 8, 1, 0);
+
   while (1) {
+    Serial_SendData(serial_port, "hello finny", 12);
+    Sleep(1000);
   }
 
   return 0;
diff --git a/app/serial.c b/app/serial.c
index 485c39b..5cf4096 100644
--- a/app/serial.c
+++ b/app/serial.c
@@ -3,6 +3,34 @@
 #include <stdio.h>
 #include <windows.h>
 
+/***
+ * 用于串口初始化时设置停止位
+ * stopbits只有三种选择
+ * 1.停止位为1
+ * 2.停止位为1.5
+ * 3.停止位为2
+ * 如果输入错误停止位则返回-1
+ */
+static int switch_get_stopbits(int stopbits) {
+  int real_stopbits;
+  switch (stopbits) {
+    case 1:
+      real_stopbits = ONESTOPBIT;
+      break;
+    case 2:
+      real_stopbits = ONE5STOPBITS;
+      break;
+    case 3:
+      real_stopbits = TWOSTOPBITS;
+      break;
+
+    default:
+      real_stopbits = -1;
+      break;
+  }
+  return real_stopbits;
+}
+
 PORT OpenPort(int idx) {
   HANDLE hComm;
   TCHAR  comname[100];
@@ -166,8 +194,10 @@ PORT serial_init(int idx, int rate, int databits, int stopbits, int parity) {
     printf("set COM%d databits fail\n", idx);
     return NULL;
   }
-  stopbits = ONESTOPBIT;
-  printf("stopbits %d\n", stopbits);
+  stopbits = switch_get_stopbits(stopbits);
+  if (stopbits == -1) {
+    printf("stopbits set error\n");
+  }
   ret = SetPortStopBits(com_port, stopbits);
   if (ret == FALSE) {
     printf("set COM%d stopbits fail\n", idx);
@@ -212,3 +242,21 @@ int Serial_ReciveData(PORT com_port, char *data, int len) {
 
   return NoBytesRead;
 }
+
+/* 测试函数，demo工程放在main中，但是我不需要，暂时放在这 */
+void serial_test(int serial_com_id) {
+  PORT COM1;
+  char buff[1024] = {0};
+  int  rcv_len    = 0;
+
+  printf("Start open com%d\n", serial_com_id);
+  COM1 = serial_init(serial_com_id, 115200, 8, 1, 0);
+
+  while (1) {
+    Serial_SendData(COM1, "hello finny", 12);
+    memset(buff, 0, 1024);
+    rcv_len = Serial_ReciveData(COM1, buff, 1024);
+    printf("rcv:%s\n", buff);
+    Sleep(1);
+  }
+}
diff --git a/app/serial.h b/app/serial.h
index 0c37ad5..fc639b0 100644
--- a/app/serial.h
+++ b/app/serial.h
@@ -19,4 +19,7 @@ PORT serial_init(int idx, int rate, int databits, int stopbits, int parity);
 int  Serial_SendData(PORT com_port, const char *data, int len);
 int  Serial_ReciveData(PORT com_port, char *data, int len);
 
+/* 测试函数，demo工程放在main中，但是我不需要，暂时放在这 */
+void serial_test(int serial_com_id);
+
 #endif
diff --git a/app/steering_gear.c b/app/steering_gear.c
new file mode 100644
index 0000000..e69de29
diff --git a/app/steering_gear.h b/app/steering_gear.h
new file mode 100644
index 0000000..e69de29