#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <stdio.h>
#include <string.h>
#include <errno.h>

#include <linux/i2c-dev.h>

int main() {
  int file;
  int adapter_nr = 1; // 1 for rPi rev 2, 0 for rev 1
  char filename[20];

  snprintf(filename, 19, "/dev/i2c-%d", adapter_nr);
  file = open(filename, O_RDWR);
  if (file < 0) {
    /* ERROR HANDLING; you can check errno to see what went wrong */
    exit(1);
  }

  int addr = 0x1e;
  if (ioctl(file, I2C_SLAVE, addr) < 0) {
    /* ERROR HANDLING; you can check errno to see what went wrong */
    exit(1);
  }
  i2c_smbus_write_word_data(file, 0x02, 0x00);

  unsigned char values[6];
  values[0] = i2c_smbus_read_word_data(file, 0x03);
  values[1] = i2c_smbus_read_word_data(file, 0x04);
  values[2] = i2c_smbus_read_word_data(file, 0x05);
  values[3] = i2c_smbus_read_word_data(file, 0x06);
  values[4] = i2c_smbus_read_word_data(file, 0x07);
  values[5] = i2c_smbus_read_word_data(file, 0x08);

  // print out result
  printf("Values: X MSB: %d, X LSB: %d, Y MSB: %d, Y LSB: %d, Z MSB: %d, Z LSB: %d\n",
    values[0],values[1],values[2],values[3],values[4],values[5]);
  unsigned char status;
  status = i2c_smbus_read_word_data(file, 0x09);
  printf("Status: %d",status);

  return 0;
}