MPU9255 is an upgrade for MPU99250. Both MPU9255 and MPU9250 integrate MPU6515+AK8963 with the same interfaces (I2C and SPI). The main difference is in the internal firmware. The MPU-9255 includes support for Automatic Activity Recognition (AARTM) on a wrist-worn device such as smart watch. It works in conjunction with the AAR™ library to detect walk, run, bike, stationary, and sleep.

 Features

• Three 16-bit analog-to-digital converters (ADCs) for digitizing the gyroscope outputs
• Three 16-bit ADCs for digitizing the accelerometer outputs
• Gyroscope full-scale range of ±250, ±500, ±1000, and ±2000°/sec (dps)
• Accelerometer full-scale range of ±2g, ±4g, ±8g, and ±16g
• Magnetometer full-scale range of ±4800μT
• I2C and SPI serial interfaces
• Internal Digital Motion Processing engine supports advanced MotionProcessing and low power functions such as gesture recognition using programmable interrupts
• Voltage supply: 3-5v

MPU9255 Arduino learning detailed tutorial

MPU 9255 datasheet