#ifndef PARAM_HOTSPOT_SSID
#define PARAM_HOTSPOT_SSID "Fsr" // your AP SSID
#endif

#ifndef PARAM_HOTSPOT_PSK
#define PARAM_HOTSPOT_PSK "12345678" // your AP PSK
#endif
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//连接wifi
    WifiDeviceConfig config = {0};

    // 准备AP的配置参数
    strcpy(config.ssid, PARAM_HOTSPOT_SSID);
    strcpy(config.preSharedKey, PARAM_HOTSPOT_PSK);
    config.securityType = PARAM_HOTSPOT_TYPE;

    osDelay(10);
    //开始连接
    int netId = ConnectToHotspot(&config);

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// 1.创建udp
    int sock_fd;
    int ret;
    sock_fd = socket(AF_INET, SOCK_DGRAM, 0); //SOCK_DGRAM：UDP类型的socket
    if (sock_fd < 0)
    {
        perror("sock_fd create error\r\n");
        return;
    }

    // 2.配置地址
    struct sockaddr_in send_addr;
    socklen_t send_addr_len = sizeof(send_addr);
    //内存初始化
    memset((void *)&send_addr, 0, send_addr_len);
    send_addr.sin_family = AF_INET;

    send_addr.sin_addr.s_addr = inet_addr("192.168.11.41"); // 是将一个点分十进制的IP转换成一个长整数型数（u_long类型）
    send_addr.sin_port = htons(1234);                       // 端口号，从主机字节序转为网络字节序
    // 3.配置发送消息
    char *msg = "hello world";
    while (1)
    {
        //4.发送
        // UDP socket 是 “无连接的” ，因此每次发送都必须先指定目标主机和端口，主机可以是多播地址
        ret = sendto(sock_fd, msg, strlen(msg), 0, (struct sockaddr *)&send_addr, send_addr_len);
        printf("send UDP message {%s}done!\r\n", msg);
        usleep(1 * 1000 * 1000);

        // 5.接收
        struct sockaddr_in fromAddr = {0};
        socklen_t fromLen = sizeof(fromAddr);
        // UDP socket 是 “无连接的” ，因此每次接收时前并不知道消息来自何处，通过 fromAddr 参数可以得到发送方的信息（主机、端口号）
        ret = recvfrom(sock_fd, &response, sizeof(response), 0, (struct sockaddr *)&fromAddr, &fromLen);
        if (ret <= 0)
        {
            printf("recvfrom failed or abort, %ld!\r\n", ret);
        }
        response[ret] = '\0';
        printf("recv UDP message {%s} %ld done!\r\n", response, ret);
        printf("peer info: ipaddr = %s, port = %d\r\n", inet_ntoa(fromAddr.sin_addr), ntohs(fromAddr.sin_port)); //将网络地址转换成“.”点隔的字符串格式。将一个16位数由网络字节顺序转换为主机字节顺序
    }
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int sockfd = socket(AF_INET, type, 0);
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// 1.创建udp
    int sock_fd;
    int ret;
    sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sock_fd < 0)
    {
        perror("sock_fd create error\r\n");
        return;
    }

    // 2.设置广播模式
    int yes = 1;
    ret = setsockopt(sock_fd, SOL_SOCKET, SO_BROADCAST, (char *)&yes, sizeof(yes)); 
    // SOL_SOCKET表示给当前的socketfd，赋予SO_BROADCAST广播权限
    if (ret == -1)
    {
        perror("setsockopt error\r\n");
        return;
    }

    // 3.配置广播地址
    struct sockaddr_in broadcast_addr;
    socklen_t broadcast_addr_len = sizeof(broadcast_addr);
    //初始化地址内存
    memset((void *)&broadcast_addr, 0, broadcast_addr_len);
    broadcast_addr.sin_family = AF_INET;
    broadcast_addr.sin_addr.s_addr = htonl(INADDR_BROADCAST); //INADDR_BROADCAST：要发送给所有主机的地址
    broadcast_addr.sin_port = htons(1234);

    char *msg = "hello ";
    while (1)
    {
        ret = sendto(sock_fd, msg, strlen(msg), 0, (struct sockaddr *)&broadcast_addr, broadcast_addr_len);

        usleep(1 * 1000 * 1000);
    }
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setsockopt(sock_fd, SOL_SOCKET, SO_BROADCAST, (char *)&yes, sizeof(yes)); 
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int setsockopt( int socket, int level, int option_name,const void *option_value, size_t ，ption_len);
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 broadcast_addr.sin_addr.s_addr = htonl(INADDR_BROADCAST); //INADDR_BROADCAST:要发送给所有主机的地址
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