基于linux的CAN通讯示例程序

#include <sys/ioctl.h> #include <net/if.h> #include <linux/can.h> #include <string.h> #include <stdlib.h> #include <stdio.h> #include <unistd.h> #include <fcntl.h> //文件控制定义 #ifndef PF_CAN #define PF_CAN 29 #endif #ifndef AF_CAN #define AF_CAN PF_CAN #endif #define CAN_COMMAND "ip link set can0 type can bitrate 50000 triple-sampling on" #define CAN_UP "ip link set can0 up" #define CAN_DOWN "ip link set can0 down" #define CAN_PORT "can0" #define FALSE -1 struct sockaddr_can addr; //打开CAN接口连接并绑定 int CAN_Open(void) { int s; struct ifreq ifr; int ret = 0; //初始化CAN接口，波特率为50K system(CAN_DOWN); system(CAN_COMMAND); usleep(50); system(CAN_UP); usleep(50); //建立socketCAN连接 s = socket(PF_CAN,SOCK_RAW,CAN_RAW); strcpy((char *)(ifr.ifr_name),CAN_PORT); ioctl(s,SIOCGIFINDEX,&ifr); printf("can0 can_ifindex = %x\n",ifr.ifr_ifindex); //绑定 addr.can_family = AF_CAN; addr.can_ifindex = ifr.ifr_ifindex; ret = bind(s,(struct sockaddr*)&addr,sizeof(addr)); if(ret < 0) { printf("in bind error \n"); } return s; } //关闭CAN接口连接 int CAN_Close(void) { return system(CAN_DOWN); } //向CAN接口发送一帧数据 int CAN_Send(int s,int len,char *msg) { int i; int nbytes; struct can_frame sendf; if(len < 4) return -1; memset(&sendf, 0, sizeof(struct can_frame)); sendf.can_id = (((int)msg[0]<<24) | ((int)msg[1] <<16) | ((int)msg[2]<<8) | (int)msg[3]) | CAN_EFF_FLAG; printf("frame.can_id = %x\n",sendf.can_id); for(i=0;i<len-4;i++) sendf.data[i] = msg[4+i]; printf("frame.data = %s\n",sendf.data); sendf.can_dlc = len-4; nbytes = sendto(s,&sendf,sizeof(struct can_frame),0,(struct sockaddr*)&addr,sizeof(addr)); printf("Send a CAN frame from interface num %d\n",nbytes); return nbytes; } //从CAN接口接收一帧数据 int CAN_Recv(int s,char *msg,socklen_t *len) { int i; int nbytes; struct can_frame recvf; memset(&recvf, 0, sizeof(struct can_frame)); //nbytes = recvfrom(s,&recvf,sizeof(struct can_frame),0,(struct sockaddr *)&addr,len); nbytes = recvfrom(s,&recvf,sizeof(struct can_frame),0,NULL,len); printf("receive a can frame from interface %d\n",addr.can_ifindex); printf( "--can_id = %x\n" "--can_dle =%x\n" "--data=",recvf.can_id,recvf.can_dlc); for (i = 0; i < recvf.can_dlc; ++i) printf("%02x ", recvf.data[i]); if(nbytes < 0) perror("recv error:"); } int main(int argc, char **argv) { int can_fd; char senddata[5] = {0x03,0x08,0x00,0x0B,0x01}; char recvdata[20]; char len; can_fd = CAN_Open(); if(CAN_Send(can_fd,0x05,senddata) > 0) printf("can send ok"); CAN_Recv(can_fd,recvdata,len); CAN_Close(); return 0; } //int main() //{ // int s; // unsigned int nbytes; // struct sockaddr_can addr; // struct ifreq ifr; // struct can_frame sendf, recvf; // int flag_num = 0; // char message[1024] = {0}; // unsigned int len; // int ret = 0,flag = 0; // int i = 0; // system(CAN_DOWN); // system(CAN_COMMAND); // usleep(50); // system(CAN_UP); // usleep(50); // s = socket(PF_CAN,SOCK_RAW,CAN_RAW); // strcpy((char *)(ifr.ifr_name),"can0"); // ioctl(s,SIOCGIFINDEX,&ifr); // printf("can0 can_ifindex = %x\n",ifr.ifr_ifindex); // addr.can_family = AF_CAN; // addr.can_ifindex = ifr.ifr_ifindex; // ret = bind(s,(struct sockaddr*)&addr,sizeof(addr)); // if(ret < 0) // { // printf("in bind error \n"); // exit(1); // } // while(1) // { // printf("Select 1 : send can frame\n"); // printf("Select 2 : receive can frame\n"); // printf("Select 3 : terminate this program\n"); // printf("please input:"); // scanf("%d",&flag_num); // getchar(); // switch(flag_num) // { // case 1: // memset(&sendf, 0, sizeof(struct can_frame)); // sendf.can_id = 0x123; // memset(message,'\0',sizeof(message)); // printf("Please input data not exceeding 8 characters:"); // scanf("%[^\n]",message); // strcpy((char *)sendf.data,message); // printf("frame.data = %s\n",sendf.data); // sendf.can_dlc = strlen(sendf.data); // nbytes = sendto(s,&sendf,sizeof(struct can_frame),0,(struct sockaddr*)&addr,sizeof(addr)); // printf("Send a CAN frame from interface %d num %d\n",ifr.ifr_ifindex,nbytes); // break; // case 2: // memset(&recvf, 0, sizeof(struct can_frame)); // nbytes = recvfrom(s,&recvf,sizeof(struct can_frame),0,(struct sockaddr *)&addr,&len); // printf("receive a can frame from interface %d\n",addr.can_ifindex); // printf( "--can_id = %x\n" // "--can_dle =%x\n" // "--data=",recvf.can_id,recvf.can_dlc); // for (i = 0; i < recvf.can_dlc; ++i) // printf("%c", recvf.data[i]); // printf("\n"); // break; // case 3: // flag = 1; // break; // default: // printf("\nplease select correct number\n"); // } // if (flag == 1) // break; // } // system(CAN_DOWN); // return 0; //}