stm32单片机tcp

STM32单片机可以通过TCP/IP协议栈实现TCP通信。下面提供两个模板供您参考：

1. STM32作TCP服务器，实现PC多客户端连接的模板

// 多连接处理部分的代码在tcp_server_demo.c中
// 其他型号型号可参考修改

#include "lwip/opt.h"
#include "lwip/arch.h"
#include "lwip/api.h"
#include "lwip/sys.h"
#include "lwip/tcp.h"
#include "lwip/sockets.h"
#include "lwip/inet.h"

#define TCP_SERVER_PORT 5005
#define TCP_SERVER_MAX_CONNECTIONS 2

static void tcp_server_thread(void *arg)
{
    int sock, newsock, n;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_addr_len;
    char recv_buf[1024];
    char send_buf[1024];

    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0) {
        printf("socket error\n");
        return;
    }

    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(TCP_SERVER_PORT);
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);

    if (bind(sock, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        printf("bind error\n");
        return;
    }

    if (listen(sock, TCP_SERVER_MAX_CONNECTIONS) < 0) {
        printf("listen error\n");
        return;
    }

    while (1) {
        client_addr_len = sizeof(client_addr);
        newsock = accept(sock, (struct sockaddr *)&client_addr, &client_addr_len);
        if (newsock < 0) {
            printf("accept error\n");
            continue;
        }

        while (1) {
            n = recv(newsock, recv_buf, sizeof(recv_buf), 0);
            if (n <= 0) {
                printf("recv error\n");
                break;
            }

            // 处理接收到的数据
            // ...

            sprintf(send_buf, "received %d bytes\n", n);
            n = send(newsock, send_buf, strlen(send_buf), 0);
            if (n <= 0) {
                printf("send error\n");
                break;
            }
        }

        close(newsock);
    }
}

void tcp_server_init(void)
{
    sys_thread_new("tcp_server_thread", tcp_server_thread, NULL, 1024, 2);
}

2. 基于正点原子STM32F407开发板调试，ModbusTCP服务器源程序

// 采用LWIP网络通讯库
// 使用 modbus poll工具调试通过
// 该工程可直接作为模板开发

#include "lwip/opt.h"
#include "lwip/arch.h"
#include "lwip/api.h"
#include "lwip/sys.h"
#include "lwip/tcp.h"
#include "lwip/sockets.h"
#include "lwip/inet.h"

#define MODBUS_TCP_PORT 502

static void modbus_tcp_thread(void *arg)
{
    int sock, newsock, n;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_addr_len;
    char recv_buf[1024];
    char send_buf[1024];

    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0) {
        printf("socket error\n");
        return;
    }

    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(MODBUS_TCP_PORT);
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);

    if (bind(sock, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        printf("bind error\n");
        return;
    }

    if (listen(sock, 1) < 0) {
        printf("listen error\n");
        return;
    }

    while (1) {
        client_addr_len = sizeof(client_addr);
        newsock = accept(sock, (struct sockaddr *)&client_addr, &client_addr_len);
        if (newsock < 0) {
            printf("accept error\n");
            continue;
        }

        while (1) {
            n = recv(newsock, recv_buf, sizeof(recv_buf), 0);
            if (n <= 0) {
                printf("recv error\n");
                break;
            }

            // 处理接收到的数据
            // ...

            n = send(newsock, send_buf, strlen(send_buf), 0);
            if (n <= 0) {
                printf("send error\n");
                break;
            }
        }

        close(newsock);
    }
}

void modbus_tcp_init(void)
{
    sys_thread_new("modbus_tcp_thread", modbus_tcp_thread, NULL, 1024, 2);
}