void getAngles() {
  byte readed = getRegisters(MPU6050, MPU6050_ACCEL_XOUT_H, buffer, 14);

  if(readed == 14)
  {
    // gyro
    float gyro_x = (int)word(buffer[8], buffer[9]);
    float gyro_y = (int)word(buffer[10], buffer[11]);
    Serial.print(mapf(gyro_x, -32768, 32767, -250, 250)); Serial.print("\t");
    Serial.print(mapf(gyro_y, -32768, 32767, -250, 250)); Serial.println();
    gyro_x = mapf(gyro_x - gyro_x_offset, -32768, 32767, -250, 250);
    gyro_y = mapf(gyro_y - gyro_y_offset, -32768, 32767, -250, 250);

    // accelerometer
    float accel_x = (int)word(buffer[0], buffer[1]);
    float accel_y = (int)word(buffer[2], buffer[3]);
    float accel_z = (int)word(buffer[4], buffer[5]);
    accel_x = mapf(accel_x, -32768, 32767, -2, 2);
    accel_y = mapf(accel_y, -32768, 32767, -2, 2);
    accel_z = mapf(accel_z, -32768, 32767, -2, 2);
    float accel_x_angle = atan2(accel_y, accel_z) * 180 / PI;
    float accel_y_angle = atan2(accel_x, accel_z) * 180 / PI;
    // complementary filter
    /*
    angle_x = 0.98 * (angle_x + gyro_x * dt / 1000.0) + 0.02 * accel_x_angle;
    angle_y = 0.98 * (angle_y - gyro_y * dt / 1000.0) + 0.02 * accel_y_angle;
    */
  }
}