udp2lcm/udp.c


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已复制！
#include "udp2lcm.h"

void udpRecvHandler() {
    int socketfd = -1;
    char buffer[MAX_BUFFER_SIZE];
    struct sockaddr_in serverAddr;
    socklen_t addrLen = sizeof(serverAddr);
    int bytesReceived;

    int retval;
    struct pollfd fds;

    printf("udpRecvHandler\n");
    if ((socketfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
        fprintf(stderr, "Error: Failed to create socket\n");
        return;
    }
    memset((char *)&serverAddr, 0, sizeof(serverAddr));
    memset(buffer, 0, sizeof(buffer));
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(PORT);
    serverAddr.sin_addr.s_addr = htonl(INADDR_ANY);

    if (bind(socketfd, (struct sockaddr *)&serverAddr, sizeof(serverAddr)) ==
        -1) {
        fprintf(stderr, "Error: Bind failed\n");
        close(socketfd);
        return;
    }

    bytesReceived = recvfrom(socketfd, buffer, MAX_BUFFER_SIZE, 0,
                             (struct sockaddr *)&clientAddr, &addrLen);
    if (bytesReceived == -1) {
        fprintf(stderr, "Error: Failed to receive data\n");
        close(socketfd);
        return;
    }
    printf("Start message from %s: %s\n", inet_ntoa(clientAddr.sin_addr),
           buffer);
    strcpy(clientIP, inet_ntoa(clientAddr.sin_addr));

    /*
     * 接收到来自手机端的第一条消息之后：
     * - 启动udpSend线程，用于向手机端发送心跳信息
     * - 通过ROBOT_COMTROL信道向算法模块发送建图开始消息
     *   - 7号命令初始坐标、初始角度、雷达扫描最大范围、机器人半径、机器人高
     *   - 30号命令开始建图，参数为单个像素点大小
     */
    if (pthread_create(&udpSend, NULL, udpSendHandler, NULL) != 0) {
        fprintf(stderr, "Error creating udpSend thread\n");
        close(socketfd);
        exit(-1);
    }

    robot_control_t robotCtrlData;
    robotCtrlInit(&robotCtrlData, 0, 7, 0, 7, 1, 0, 0);
    robotCtrlData.iparams[0] = 1;
    robot_control_t_publish(lcm, "ROBOT_CONTROL", &robotCtrlData);
    freeRobotCtrl(&robotCtrlData);
    // 随即下达30号命令，开始建图
    robotCtrlInit(&robotCtrlData, 0, 30, 0, 1, 1, 0, 0);
    robotCtrlData.dparams[0] = 0.05;
    robotCtrlData.niparams = 1;
    robotCtrlData.iparams[0] = 1;
    robot_control_t_publish(lcm, "ROBOT_CONTROL", &robotCtrlData);
    freeRobotCtrl(&robotCtrlData);

    /*
     * 开始接收来自手机端的命令
     * 限定时间为3s，超过3s未收到消息则停止轮子
     * 但不退出循环，防止是网络抖动
     */
    const path_ctrl_t path = {0, 0}; // 就是停止命令，不能改
    fds.fd = socketfd;
    fds.events = POLLIN;
    while (true) {
        retval = poll(&fds, 1, 3000);
        if (retval == -1) {
            fprintf(stderr, "Error: select failed\n");
            break;
        } else if (retval == 0) {
            // 超出3s，报错并停止前进
            fprintf(stderr, "No data within three seconds.\n");
            path_ctrl_t_publish(lcm, "wheel_ctrl", &path);
        } else {
            bytesReceived = recvfrom(socketfd, buffer, MAX_BUFFER_SIZE, 0,
                                     (struct sockaddr *)&clientAddr, &addrLen);
            if (bytesReceived == -1) {
                fprintf(stderr, "Error: Failed to receive data\n");
                continue;
            }
            printf("Massage from client %s: ", clientIP);
            for (int i = 0; i < bytesReceived; i++) {
                printf("%02x ", buffer[i]);
            }
            printf("\n");
            parseCmd(buffer, bytesReceived);
        }
    }
}

void udpSendHandler() {
    // 创建UDP套接字
    int sockfd = -1;
    struct sockaddr_in serverAddr;
    if ((sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
        fprintf(stderr, "Error: Failed to create socket\n");
        return;
    }

    memset((char *)&serverAddr, 0, sizeof(serverAddr));
    serverAddr.sin_family = AF_INET;   // 设置地址族为IPv4
    serverAddr.sin_port = htons(PORT); // 设置端口号
    if (inet_aton(clientIP, &serverAddr.sin_addr) == 0) {
        fprintf(stderr, "Error: Failed to convert IP address\n");
        close(sockfd);
        return;
    }

    while (true) {
        pthread_mutex_lock(&heartBeatMutex);
        sendto(sockfd, (const char *)heartBeat, 9, 0,
               (struct sockaddr *)&serverAddr, sizeof(serverAddr));
        pthread_mutex_unlock(&heartBeatMutex);
        sleep(1);
    }
}