cat1025.c

周立功magic2410实验箱源码 第6章Linux高级实验(part1) 6.1 Linux内核编译实验 6.2 Linux根文件系统实验 6.3 CAT1025读/写实验. 6.4 ZL

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>                                /* 文件操作 */
#include <sys/ioctl.h>				  /* ioctl()函数 */
#include "i2c.h"                                  /* I2C总线控制器驱动命令 */

#define	 I2C_ADDR 	0xA0                          /* CAT1025 从机地址 */

int main()
{
    int fd,ret,i;
    unsigned char suba;
    char buf[9] = {0,1,2,3,4,5,6,7,8};
   
	fd = open("/dev/i2c/0", O_RDWR);              /* 打开设备 */
    if(fd == -1)
    {
        printf("\nCan't open I2C device!\n");
        exit(-1);
    } 

    ret = ioctl(fd, I2C_TENBIT, 0);               /* 指定从机地址为7bit */
    if (ret != 0)
    {
    	printf("\nCan't set I2C address bit number.\n");
    	close(fd);
    	exit(-1);
    }
 
    ret = ioctl(fd, I2C_SLAVE, I2C_ADDR >> 1);    /* 设置从机地址,7位地址,须右移1位*/
    if (ret != 0)
    {
    	printf("\nCan't set I2C slave device address.\n");
    	close(fd);
    	exit(-1);
    }
         
    printf("Write CAT1025:\n"); 
	for(i = 1; i < 9; i++)
		printf("%d ", buf[i]);
       	 
    ret = write(fd, buf, 9);					  /* 写8个字节到CAT1025,第1字节为子地址 */
    if (ret != 9)
    {
    	printf("Write CAT1025 failed.\n");
    	close(fd);
    	exit(-1);
    }
    
    usleep(10000);                                /* 等待10ms写入完成 */
    
    printf("\nRead CAT1025:\n");	
    suba = 0;
    ret = write(fd, &suba, 1);					  /* 发送从机子地址 */
    if (ret != 1)
    {
    	printf("send slave address fail.\n");
    	close(fd);
    	exit(-1);
    }   	
    		 	 	
	ret = read(fd, buf, 8);       			 	  /* 从CAT1025读8个字节 */
   	if (ret == 8)
   	{
   		for (i = 0; i < 8; i++)
   			printf("%d ", buf[i]);
   	}
   	else
   	{
    	printf("Read CAT1025 failed.\n");
    	close(fd);
    	exit(-1);   		
   	}
  
  	printf("\nRead and Write CAT1025 sucessfully!\n");

    return 0;
}

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