在上一篇文章中讲了“如何通过MCU配置S2E为UDP模式”，相信小伙伴们已经了解了S2E的基本功能，在这一篇中，我们再接再厉，继续学习一下“如何通过MCU配置S2E为TCP Server的工作模式”，无论是配置UDP模式还是配置TCP模式，都是通过串口转以太网的方式实现的：
1、接线方式
2、例程说明
打开“通过MCU配置S2E为TCP Server例程”，主程序中第一部分TIM3_Init();是设定一个帧中断的时间定时器，这是因为该例程MCU的串口是通过帧中断来接收AT命令配置S2E后返回的数据的。
第二部分USARTX_Init();初始化MCU用到的串口，这里用USART1_Config();是printf功能，用于查看调试信息。USART2_Config();用于配置S2E，需要注意的是该串口的配置参数需要同S2E的串口配置参数一致，否则配置失败。
第三部分主循环中的TCP_Server_Mode();用于配置S2E为TCP Server模式。S2E的AT命令列表详见各个S2E型号的用户手册AT命令章节介绍。配置成功，串口打印“TCP Server Config Success!”，配置失败串口打印“TCP Server Config Fail!”。
/****************************************************
函数名： TCP_Server_Mode
形参： 无
返回值： 无
函数功能： 通过串口发送AT命令配置S2E模块
****************************************************/
volatile uint8_t SendFlag = 0;
void TCP_Server_Mode(void) {
uint8_t RecvFlag = 1;
char * state;
switch (SendFlag) {
case 0: {
Usart_Send(USART2, "AT\r\n");
//终端检测命令
while (RecvFlag) {
if (RX2_Point & amp; FRAME_LEN) {
//如果接收到数据
state = strstr((char * ) RecvBuff, "OK");
//判断回复的数据中是否有“OK”
if (state != NULL) {
//有
RX2_Point = 0;
//接收缓冲区指针置零
RecvFlag = 0;
//接收标致位置零
SendFlag = 1;
//发送标志位置零
printf("Recv:%s\r\n", RecvBuff);
memset(RecvBuff, 0, RECV_LEN);
//接收缓存清零
} else { //无
SendFlag = 100;
//配置失败
RecvFlag = 0;
}
}
}
}
break;
case 1: {
Usart_Send(USART2, "AT+ECHO=0\r\n");
//开启（1）/关闭（0）回显命令
RecvFlag = 1;
while (RecvFlag) {
if (RX2_Point & amp; FRAME_LEN) { //如果接收到数据
state = strstr((char * ) RecvBuff, "OK");
if (state != NULL) {
RX2_Point = 0;
RecvFlag = 0;
SendFlag = 2;
printf("Recv:%s\r\n", RecvBuff);
memset(RecvBuff, 0, RECV_LEN);
} else {
SendFlag = 100;
RecvFlag = 0;
}
}
}
}
break;
case 2: {
Usart_Send(USART2, "AT+C1_OP=0\r\n"); //配置为TCP
Server模式命令
RecvFlag = 1;
while (RecvFlag) {
if (RX2_Point & amp; FRAME_LEN) { //如果接收到数据
state = strstr((char * ) RecvBuff, "OK");
if (state != NULL) {
RX2_Point = 0;
RecvFlag = 0;
SendFlag = 3; //状态标志位置零
printf("Recv:%s\r\n", RecvBuff);
memset(RecvBuff, 0, RECV_LEN);
} else {
SendFlag = 100;
RecvFlag = 0;
}
}
}
}
break;
case 3: {
Usart_Send(USART2, "AT+IP_MODE=0\r\n");
//配置为静态IP模式
RecvFlag = 1;
while (RecvFlag) {
if (RX2_Point & amp; FRAME_LEN) { //如果接收到数据
state = strstr((char * ) RecvBuff, "OK");
if (state != NULL) {
RX2_Point = 0;
RecvFlag = 0;
SendFlag = 4; //状态标志位置零
printf("Recv:%s\r\n", RecvBuff);
memset(RecvBuff, 0, RECV_LEN);
} else {
SendFlag = 100;
RecvFlag = 0;
}
}
}
}
break;
case 4: {
Usart_Send(USART2, "AT+IP=192.168.1.88\r\n"); //配置本地IP
RecvFlag = 1;
while (RecvFlag) {
if (RX2_Point & amp; FRAME_LEN) { //如果接收到数据
state = strstr((char * ) RecvBuff, "OK");
if (state != NULL) {
RX2_Point = 0;
RecvFlag = 0;
SendFlag = 5; //状态标志位置零
printf("Recv:%s\r\n", RecvBuff);
memset(RecvBuff, 0, RECV_LEN);
} else {
SendFlag = 100;
RecvFlag = 0;
}
}
}
}
break;
case 5: {
Usart_Send(USART2, "AT+MARK=255.255.255.0\r\n");
//配置本地IP
RecvFlag = 1;
while (RecvFlag) {
if (RX2_Point & amp; FRAME_LEN) { //如果接收到数据
state = strstr((char * ) RecvBuff, "OK");
if (state != NULL) {
RX2_Point = 0;
RecvFlag = 0;
SendFlag = 6; //状态标志位置零
printf("Recv:%s\r\n", RecvBuff);
memset(RecvBuff, 0, RECV_LEN);
} else {
SendFlag = 100;
RecvFlag = 0;
}
}
}
}
break;
case 6: {
Usart_Send(USART2, "AT+GATEWAY=192.168.1.1\r\n");
//配置本地IP
RecvFlag = 1;
while (RecvFlag) {
if (RX2_Point & amp; FRAME_LEN) { //如果接收到数据
state = strstr((char * ) RecvBuff, "OK");
if (state != NULL) {
RX2_Point = 0;
RecvFlag = 0;
SendFlag = 7; //状态标志位置零
printf("Recv:%s\r\n", RecvBuff);
memset(RecvBuff, 0, RECV_LEN);
} else {
SendFlag = 100;
RecvFlag = 0;
}
}
}
}
break;
case 7: {
Usart_Send(USART2, "AT+C1_PORT=5000\r\n");
//配置本地端口号
RecvFlag = 1;
while (RecvFlag) {
if (RX2_Point & amp; FRAME_LEN) { //如果接收到数据
state = strstr((char * ) RecvBuff, "OK");
if (state != NULL) {
RX2_Point = 0;
RecvFlag = 0;
SendFlag = 8; //状态标志位置零
printf("Recv:%s\r\n", RecvBuff);
memset(RecvBuff, 0, RECV_LEN);
} else {
SendFlag = 100;
RecvFlag = 0;
}
}
}
}
break;
case 8: {
Usart_Send(USART2, "AT+START_MODE=0\r\n");
//配置启动模式（0--AT模式，1--
数据模式）
RecvFlag = 1;
while (RecvFlag) {
if (RX2_Point & amp; FRAME_LEN) { //如果接收到数据
state = strstr((char * ) RecvBuff, "OK");
if (state != NULL) {
RX2_Point = 0;
RecvFlag = 0;
SendFlag = 9; //状态标志位置零
printf("Recv:%s\r\n", RecvBuff);
memset(RecvBuff, 0, RECV_LEN);
} else {
SendFlag = 100;
RecvFlag = 0;
}
}
}
}
break;
case 9: {
Usart_Send(USART2, "AT+EXIT\r\n");
//保存配置并进入数据模式
RecvFlag = 1;
while (RecvFlag) {
if (RX2_Point & amp; FRAME_LEN) { //如果接收到数据
state = strstr((char * ) RecvBuff, "OK");
if (state != NULL) {
RX2_Point = 0;
RecvFlag = 0;
SendFlag = 99; //状态标志位置零
printf("Recv:%s\r\n", RecvBuff);
memset(RecvBuff, 0, RECV_LEN);
} else {
SendFlag = 100;
RecvFlag = 0;
}
}
}
}
break;
case 99: {
printf("TCP Server Config Success!\r\n");
Config_OK = 1;
}
default:
RecvFlag = 100;
break;
case 100: {
printf("TCP Server Config Fail!\r\n");
Config_OK = 1;
}
break;
}
}
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