c - 通过 socketCAN 发送 EFF 29 位 ID 消息的问题

Question

我正在尝试通过套接字发送 29 位 EFF CAN 消息，但由于某种原因，它使用 11 位标识符发送消息，从 ID 中删除 5 个字节。使用环回模式，通过 candump 我可以看到消息以 11 位形式接收。

我没有收到任何错误，什么也没有，这就是我感到困惑的原因

如果这有什么区别的话，我正在使用树莓派 3b+。和 Can-utils 库。

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <time.h>
#include <net/if.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>

#include <linux/can.h>
#include <linux/can/raw.h>

#include </home/pi/can-utils/lib.h>

int main(int argc, char **argv)
{
int s,loop = 1;
int nbytes;
struct sockaddr_can addr;
struct can_frame frame;
struct ifreq ifr;

//can interface 

if((s=socket(PF_CAN, SOCK_RAW, CAN_RAW))<0){
    perror("socket");
    return 1;
    }


strcpy(ifr.ifr_name, "can0");
if(ioctl(s, SIOCGIFINDEX, &ifr) < 0){
    perror("SIOCGIFINDEX");
    return 1;
    }


addr.can_family = AF_CAN;
addr.can_ifindex = ifr.ifr_ifindex;


if(bind(s,(struct sockaddr *)&addr, sizeof(addr)) < 0){
    perror("bind");
    return 1;
    }

//data send loop

while(loop){
    int g;

for (int e = 0; e < 1020; e++){
if(e < 10) {g = 0;}
    else if (e%100 == 0){ g = 1;}
        else if (e%50 == 0){ g = 2;}
            else if (e%20 == 0) {g = 3;}

if (g==0){  
switch(e){

    case 1:                 //TOTAL FUEL USED 5-8
frame.can_id = 0x0000FEE9;
    printf("value %X",frame.can_id);
frame.can_dlc = 8;
frame.data[0] = 0x00;
frame.data[1] = 0x00;
frame.data[2] = 0x00;
frame.data[3] = 0x00;
frame.data[4] = 0xF5;       //0.5L/BIT
frame.data[5] = 0x06;       //0.5L/BIT
frame.data[6] = 0x07;       //0.5L/BIT
frame.data[7] = 0x08;       //0.5L/BIT
break;

    case 2:                 //FUEL LEVEL 2
frame.can_id = 0x0000FEFC;
frame.can_dlc = 8;
frame.data[0] = 0x00;
frame.data[1] = 0x88;       //0.4%/BIT
frame.data[2] = 0x00;
frame.data[3] = 0x00;
frame.data[4] = 0x00;
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;
break;

    case 3:                 //TOTAL ENGINE HOURS 1-4
frame.can_id = 0x0000FEE5;  
frame.can_dlc = 8;
frame.data[0] = 0x11;       //0.05h/BIT
frame.data[1] = 0x22;       //0.05h/BIT
frame.data[2] = 0x33;       //0.05h/BIT
frame.data[3] = 0x44;       //0.05h/BIT
frame.data[4] = 0x00;
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;
break;

    case 4:                 //MILLEAGE 1-4
frame.can_id = 0x0000FEC1;  
frame.can_dlc = 8;
frame.data[0] = 0x44;       //5M/BIT
frame.data[1] = 0x33;       //5M/BIT
frame.data[2] = 0x22;       //5M/BIT
frame.data[3] = 0x11;       //5M/BIT
frame.data[4] = 0x00;
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;
break;

    case 5:
frame.can_id = 0x0000FEEE;  //ENGINE TEMPERATURE 1
frame.can_dlc = 8;
frame.data[0] = 0xCC;       //1C/BIT -40C OFFSET
frame.data[1] = 0x00;
frame.data[2] = 0x00;
frame.data[3] = 0x00;
frame.data[4] = 0x00;
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;
break;

    case 6:
frame.can_id = 0x0000FEF5;  //AMBIENT TEMPERATURE 4-5
frame.can_dlc = 8;
frame.data[0] = 0x00;
frame.data[1] = 0x00;
frame.data[2] = 0x00;
frame.data[3] = 0xE4;       //0.03125C/BIT -273C OFFSET
frame.data[4] = 0xF2;       //0.03125C/BIT -273C OFFSET
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;
break;

    case 7:                 //HIGH RES FUEL 5-8
frame.can_id = 0x0000FD09;  
frame.can_dlc = 8;
frame.data[0] = 0x00;       
frame.data[1] = 0x00;
frame.data[2] = 0x00;
frame.data[3] = 0x00;
frame.data[4] = 0x01;       //0.001L/BIT
frame.data[5] = 0x02;       //0.001L/BIT
frame.data[6] = 0x03;       //0.001L/BIT
frame.data[7] = 0x04;       //0.001L/BIT
break;

    case 8:             //VEHICLE WEIGHT 2-3
frame.can_id = 0x0000FEEA;  
frame.can_dlc = 8;
frame.data[0] = 0x00;
frame.data[1] = 0x05;       //0.5KG/BIT
frame.data[2] = 0xFF;       //0.5KG/BIT
frame.data[3] = 0x00;
frame.data[4] = 0x00;
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;
break;

    case 9:             //DISTANCE BEFORE SERVICE 2-3
frame.can_id = 0x0000FEC0;  
frame.can_dlc = 8;
frame.data[0] = 0x00;
frame.data[1] = 0xEF;       //5KM/BIT -160 635 KM OFFSET
frame.data[2] = 0xCD;       //5KM/BIT -160 635 KM OFFSET
frame.data[3] = 0x00;
frame.data[4] = 0x00;
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;
break;
    default:    
    break;
}

for(int i = 0; i <1; i++){
    if ((nbytes = write(s, &frame, sizeof(struct can_frame))) != sizeof(frame)){
        }
    }
}

if (g == 1){
    for(int l = 1; l < 5; l++){
        switch(l){
    case 1:                 //EEC 3-5
frame.can_id = 0x000CF004;
frame.can_dlc = 8;
frame.data[0] = 0x00;
frame.data[1] = 0x00;
frame.data[2] = 0xEE;       //TORQUE 1%/BIT -125% OFFSET
frame.data[3] = 0xEF;       //RPM 0.125/BIT
frame.data[4] = 0x12;       //RPM 0.125/BIT
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;
break;

    case 2:                 //FUEL ECONOMY 1-4
frame.can_id = 0x0000FEF2;  
frame.can_dlc = 8;
frame.data[0] = 0xEC;       //FUEL RATE (0.05L/h)/BIT 
frame.data[1] = 0xFF;       //FUEL RATE (0.05L/h)/BIT 
frame.data[2] = 0x15;       //CURRENT FUEL (1/512KM/L)/BIT 
frame.data[3] = 0xE5;       //CURRENT FUEL (1/512KM/L)/BIT 
frame.data[4] = 0x00;
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;
break;  

    case 3:                 //WHEEL SPEED 2-3
frame.can_id = 0x0000FEF1;  
frame.can_dlc = 8;
frame.data[0] = 0x00;       
frame.data[1] = 0x01;       //(1/256KM/h)/BIT
frame.data[2] = 0x99;       //(1/256KM/h)/BIT
frame.data[3] = 0x00;
frame.data[4] = 0x00;
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;
break;

    case 4:             //EEC2 2-3
frame.can_id = 0x0000F003;
frame.can_dlc = 8;
frame.data[0] = 0x00;       
frame.data[1] = 0x03;       //0.4%/BIT CCELERATOR POSITION 
frame.data[2] = 0x55;       //1%/BIT ENGINE LOAD
frame.data[3] = 0x00;
frame.data[4] = 0x00;
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;
break;  
}
        for(int i = 0; i <1; i++){
    if ((nbytes = write(s, &frame, sizeof(struct can_frame))) != sizeof(frame)){
        }
    }
    if(l<5) usleep(1000);
}

}
else if (g == 2){

frame.can_id = 0x0000F003;
frame.can_dlc = 8;
frame.data[0] = 0x00;       
frame.data[1] = 0x03;       //0.4%/BIT CCELERATOR POSITION 
frame.data[2] = 0x55;       //1%/BIT ENGINE LOAD
frame.data[3] = 0x00;
frame.data[4] = 0x00;
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;

for(int i = 0; i <1; i++){
    if ((nbytes = write(s, &frame, sizeof(struct can_frame))) != sizeof(frame)){
        }
    }
    }
else if (g == 3){

frame.can_id = 0x0000F004;
frame.can_dlc = 8;
frame.data[0] = 0x00;
frame.data[1] = 0x00;
frame.data[2] = 0xEE;       //TORQUE 1%/BIT -125% OFFSET
frame.data[3] = 0xEF;       //RPM 0.125/BIT
frame.data[4] = 0x12;       //RPM 0.125/BIT
frame.data[5] = 0x00;
frame.data[6] = 0x00;
frame.data[7] = 0x00;

for(int i = 0; i <1; i++){
    if ((nbytes = write(s, &frame, sizeof(struct can_frame))) != sizeof(frame)){
        }
    }
    }
usleep(10000);
g = 5;
if(e==900) e = 0;
}
}                   

close(s);
return 0; 
}

Answer 1

设置can_id后需要添加正确的标志:

frame.can_id |= CAN_EFF_FLAG;

或者例如:而不是

frame.can_id = 0x0000FEE9

使用

frame.can_id = 0x0000FEE9U | CAN_EFF_FLAG ;

这里 U 表示您的整数文字是无符号的。另请参阅https://github.com/linux-can/can-utils/blob/master/include/linux/can.h