arm linux 下使用iic总线节点读取外挂设备

/************************************************************/
: (1)
//          (2)
//          (3)
//          (4)

//鏃ユ湡:2016-10-03
/************************************************************/
//鍖呭惈澶存枃浠�
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/select.h>
#include <sys/time.h>
#include <errno.h>

//瀹忓畾涔�

#define SMPLRT_DIV  0x19    
#define CONFIG  0x1A    
#define GYRO_CONFIG 0x1B    
#define ACCEL_CONFIG    0x1C
#define ACCEL_XOUT_H    0x3B
#define ACCEL_XOUT_L    0x3C
#define ACCEL_YOUT_H    0x3D
#define ACCEL_YOUT_L    0x3E
#define ACCEL_ZOUT_H    0x3F
#define ACCEL_ZOUT_L    0x40
#define TEMP_OUT_H  0x41
#define TEMP_OUT_L  0x42
#define GYRO_XOUT_H 0x43
#define GYRO_XOUT_L 0x44
#define GYRO_YOUT_H 0x45
#define GYRO_YOUT_L 0x46
#define GYRO_ZOUT_H 0x47
#define GYRO_ZOUT_L 0x48
#define PWR_MGMT_1  0x6B
#define WHO_AM_I    0x75    
#define SlaveAddress    0xD0    

#define Address 0x68                  //MPU6050鍦板潃

#define I2C_RETRIES   0x0701
#define I2C_TIMEOUT   0x0702
#define I2C_SLAVE     0x0703       //IIC浠庡櫒浠剁殑鍦板潃璁剧疆
#define I2C_BUS_MODE   0x0780

typedef unsigned char uint8;

int fd = -1;

//鍑芥暟澹版槑
static uint8 MPU6050_Init(void);
static uint8 i2c_write(int fd, uint8 reg, uint8 val);
static uint8 i2c_read(int fd, uint8 reg, uint8 *val);
static uint8 printarray(uint8 Array[], uint8 Num);

//MPU6050鍒濆鍖�
static uint8 MPU6050_Init(void)
{
    fd = open("/dev/i2c-0", O_RDWR);   // open file and enable read and  write

    if(fd < 0)
    {
        perror("Can't open /dev/MPU6050 \n"); // open i2c dev file fail
        exit(1);
    }
    printf("open /dev/i2c-0 success !\n");   // open i2c dev file succes

    if(ioctl(fd, I2C_SLAVE, Address)<0) {    //set i2c address 
        printf("fail to set i2c device slave address!\n");
        close(fd);
        return -1;
    }
    printf("set slave address to 0x%x success!\n", Address);

    i2c_write(fd,PWR_MGMT_1,0X00);    
    i2c_write(fd,SMPLRT_DIV,0X07); 
    i2c_write(fd,CONFIG,0X06); 
    i2c_write(fd,ACCEL_CONFIG,0X01); 

    return(1);
}

//MPU6050 wirte byte
static uint8 i2c_write(int fd, uint8 reg, uint8 val)
{
    int retries;
    uint8 data[2];

    data[0] = reg;
    data[1] = val;
    for(retries=5; retries; retries--) {
        if(write(fd, data, 2)==2)
            return 0;
        usleep(1000*10);
    }
    return -1;
}

//MPU6050 read byte
static uint8 i2c_read(int fd, uint8 reg, uint8 *val)
{
    int retries;

    for(retries=5; retries; retries--)
//      if(write(fd, &reg, 1)==1)
//          if(read(fd, val, 1)==1)
                return 0;
    return -1;
}

//get data
short GetData(unsigned char REG_Address)
{
    char H,L;
    i2c_read(fd, REG_Address, &H);
    i2c_read(fd, REG_Address + 1, &L);

    return (H<<8)+L;
}
// main
int main(int argc, char *argv[])
{
    MPU6050_Init();
    usleep(1000*100);
    while(1)
    {
        printf("\033[2J");
        usleep(1000*200);
        printf("ACCE_X:%6d\n ",GetData(ACCEL_XOUT_H));
        printf("ACCE_Y:%6d\n ",GetData(ACCEL_YOUT_H));
        printf("ACCE_Z:%6d\n ",GetData(ACCEL_ZOUT_H));
        printf("GYRO_X:%6d\n ",GetData(GYRO_XOUT_H));
        printf("GYRO_Y:%6d\n ",GetData(GYRO_YOUT_H));
        printf("GYRO_Z:%6d\n ",GetData(GYRO_ZOUT_H));
    }

    close(fd);
}