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I.MX6 Android 平台CAN总线调试（包含测试C语言代码）

2019-07-12 13:59发布生成海报

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I.MX6 Android 平台CAN总线调试（包含测试C语言代码）

前言：这几天需要调试NXP Android平台CAN总线，以前到工作中都没有接触过can总线，折腾了几天，终于通信成功。至于can总线的原理我就不细说了，网上很多，原理很复杂，也比较难懂，我们主要还是学习如何使用就可以了。这里就记录以下在android平台下如何使用can进行通信。一、外围电路CAN总线收发驱动电路。

二、在imx6q的的BSP中已经有了CAN总线的驱动，驱动的源代码在drivers etcanflexcan.c，一般情况下已经打开了CAN功能，如果没打开的话进入kernel代码执行make menuconfig对内核进行配置,如下图，具体的设置就不细说。

三、adb shell进入调试模式，使用iproute2工具到ip命令，查看和设置can参数，这个工具android已经集成有，直接使用。
        ifconfig -a //确认是否有can0 和can1存在
        ifconfig can0 down         //关闭can0，以便配置
        ip link set can0 up type can bitrate 500000         //设置can0波特率
        ip link set can0 up // 启动can0
        ip link set can0 down // 关闭can0
        ip -details -statistics link show can0 //查看统一参数
        ip -details link show can0 //查看统一参数

四、PC端用工具跟ARM开发板进行can通信。 4.1、arm开发板can总线收发can数据测试c语言代码。

 /*
 *  can_test_send_and_dump.c
 *
 *  Created on: 2018-8-25
 *  Author: tanghanyue
*/

#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 
#include 

int main(int argc, char *argv[])
{
	int s, nbytes;
        unsigned char number=0;
	struct sockaddr_can addr;
	struct ifreq ifr;
	struct can_frame frame;
        struct can_frame frame_send;
	struct can_filter rfilter[1];
        pid_t pid = -1;
	int i;
	/* handle (optional) flags first */
	if(argc != 2) {
	    fprintf(stderr, "Usage:  %s <-r>  for receiving
or <-s>  for sending
", argv[0]);
	    exit(1);
	}
	/* create socket */
	if ((s = socket(PF_CAN, SOCK_RAW, CAN_RAW)) < 0)
	{
	   perror("Create socket failed");
	   exit(-1);
	}

	/* set up can interface */
	strcpy(ifr.ifr_name, argv[1]);
	printf("can port is %s
",ifr.ifr_name);
	/* assign can device */
	ioctl(s, SIOCGIFINDEX, &ifr);
	    addr.can_family = AF_CAN;
	addr.can_ifindex = ifr.ifr_ifindex;
	    /* bind can device */
	if(bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0)
	{
	     perror("Bind can device failed
");
	     close(s);
	     exit(-2);
	}

        pid = fork();
        if(pid == -1) 
        { 
             perror("
	failed to fork!!

");
             return  -1;
        }
        else if(pid==0)/* configure receiving can data*/
	{
	   /* set filter for only receiving packet with can id 0x88 */
	   rfilter[0].can_id = 0x88;
	   rfilter[0].can_mask = CAN_SFF_MASK;
	   if(setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, &rfilter, sizeof(rfilter)) < 0)
	   {
	        perror("set receiving filter error
");
	        close(s);
	        exit(-3);
	   }
	   /* keep reading */
	   while(1){

	       nbytes = read(s, &frame, sizeof(frame));
	       if(nbytes > 0)
	       {
		   printf("read datas:%s ID=%#x data length=%d
", ifr.ifr_name, frame.can_id, frame.can_dlc);
		   for ( i=0; i < frame.can_dlc; i++)
		        printf("%#x ", frame.data[i]);
		   printf("
");
	       }
	       printf("read can data over
");

	   }
	}/* configure sending can data*/
        else
	{   
              while(1)
              {
		/* configure can_id and can data length */
	        frame_send.can_id = 0x88;
		frame_send.can_dlc = 8;
		printf("%s ID=%#x data length=%d
", ifr.ifr_name, frame_send.can_id, frame_send.can_dlc);
		/* prepare data for sending: 0x11,0x22...0x88 */
		for (i=0; i<8; i++)
		{
		    frame_send.data[i] = ((i+1)<<4) | (i+1);
                    frame_send.data[7] =number;
		    printf("%#x ", frame_send.data[i]);
		}
		printf("success to Sent out
");
		/* Sending data */
		if(write(s, &frame_send, sizeof(frame_send)) < 0)
	        {
		    perror("Send failed");
		    close(s);
		    exit(-4);
	        }
                sleep(1);
                number++;
             }
            
	 }
	close(s);
	return 0;
}

4.2、PC通过USB口连接到CAN分析仪，将arm开发板到can端口连接到can分析仪。