brief 程序注释

/**
* @brief Acceleration (g's) in body frame.
* Embedded MPL defines gravity as positive acceleration pointing away from
* the Earth.
* @param[out] data Acceleration in g's, q16 fixed point.
* @param[out] accuracy Accuracy of the measurement from 0 (least accurate)
* to 3 (most accurate).
* @param[out] timestamp The time in milliseconds when this sensor was read.
* @return 1 if data was updated.
*/