#include //#define CHIP_ADDR 0x20

#define I2C_DEV "/dev/i2c-0"//i2c_dev为i2c　adapter创建的别名

//读操作先发Slaveaddr_W+Regaddr_H+Regaddr_L 3个字节来告诉设备操作器件及两个byte参数

//然后发送Slaveaddr_R读数据

static int iic_read(int fd, char buff[], int addr, int count)

{

int res;

char sendbuffer1[2];

sendbuffer1[0]=addr>>8;

sendbuffer1[1]=addr;

write(fd,sendbuffer1,2);

res=read(fd,buff,count);

printf("read %d byte at 0x%x\n", res, addr);

return res;

}

//在写之前，在数据前加两个byte的参数，根据需要解析

static int iic_write(int fd, char buff[], int addr, int count)

{

int res;

int i,n;

static char sendbuffer[100];

memcpy(sendbuffer+2, buff, count);

sendbuffer[0]=addr>>8;

sendbuffer[1]=addr;

res=write(fd,sendbuffer,count+2);

printf("write %d byte at 0x%x\n", res, addr);

}

int main(void){

int fd;

int res;

char ch;

char buf[50];

int regaddr,i,slaveaddr;

fd = open(I2C_DEV, O_RDWR);// I2C_DEV /dev/i2c-0

if(fd < 0){

printf("####i2c test device open failed####\n");

return (-1);

}

printf("please input slave addr:");

scanf("%x",&slaveaddr);

printf("input slave addr is:%x\n",slaveaddr);

printf("please input reg addr:");

scanf("%x",&regaddr);

printf("input slave addr is:%x\n",regaddr);

res = ioctl(fd,I2C_TENBIT,0);   //not 10bit

res = ioctl(fd,I2C_SLAVE,slaveaddr);    //设置I2C从设备地址[6:0]

while((ch=getchar())!='0'){

switch(ch){

case '1':

printf("getch test success\n");

break;

case '2':

buf[0]=0xFF;

buf[1]=0xFF;

buf[2]=0xFF;

buf[3]=0xFF;

buf[4]=0xFF;

printf("read i2c test\n");

res=iic_read(fd,buf,regaddr,5);

printf("%d bytes read:",res);

for(i=0;iprintf("%d ",buf[i]);

}

printf("\n");

break;

case '3':

buf[0]=0xAA;

buf[1]=0x55;

buf[2]=0xAA;

printf("write i2c test\n");

res=iic_write(fd,buf,regaddr,2);

printf("%d bytes write success\n");

break;

default:

printf("bad command\n");

break;

}

}

return 0;

}