text: //*****************************************************************************
  //
  // mpu9150.h - Prototypes for the MPU9150 accelerometer, gyroscope, and
  //             magnetometer driver.
  //
  // Copyright (c) 2013-2017 Texas Instruments Incorporated.  All rights reserved.
  // Software License Agreement
  // 
  // Texas Instruments (TI) is supplying this software for use solely and
  // exclusively on TI's microcontroller products. The software is owned by
  // TI and/or its suppliers, and is protected under applicable copyright
  // laws. You may not combine this software with "viral" open-source
  // software in order to form a larger program.
  // 
  // THIS SOFTWARE IS PROVIDED "AS IS" AND WITH ALL FAULTS.
  // NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT
  // NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. TI SHALL NOT, UNDER ANY
  // CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
  // DAMAGES, FOR ANY REASON WHATSOEVER.
  // 
  // This is part of revision 2.1.4.178 of the Tiva Firmware Development Package.
  //
  //*****************************************************************************
  
  #ifndef __SENSORLIB_MPU9150_H__
  #define __SENSORLIB_MPU9150_H__
  
  //*****************************************************************************
  //
  // If building with a C++ compiler, make all of the definitions in this header
  // have a C binding.
  //
  //*****************************************************************************
  #ifdef __cplusplus
  extern "C"
  {
  #endif
  
  //*****************************************************************************
  //
  // The structure that defines the internal state of the MPU9150 driver.
  //
  //*****************************************************************************
  typedef struct
  {
      //
      // The pointer to the I2C master interface instance used to communicate
      // with the MPU9150.
      //
      tI2CMInstance *psI2CInst;
  
      //
      // The AK8975 inst that used to access the on-chip AK8975 magnetometer
      //
      tAK8975 sAK8975Inst;
  
      //
      // The I2C address of the MPU9150.
      //
      uint8_t ui8Addr;
  
      //
      // The state of the state machine used while accessing the MPU9150.
      //
      uint8_t ui8State;
  
      //
      // The current accelerometer afs_sel setting
      //
      uint8_t ui8AccelAfsSel;
  
      //
      // The new accelerometer afs_sel setting, which is used when a register
      // write succeeds.
      //
      uint8_t ui8NewAccelAfsSel;
  
      //
      // The current gyroscope fs_sel setting
      //
      uint8_t ui8GyroFsSel;
  
      //
      // The new gyroscope fs_sel setting, which is used when a register write
      // succeeds.
      //
      uint8_t ui8NewGyroFsSel;
  
      //
      // The data buffer used for sending/receiving data to/from the MPU9150.
      //
      uint8_t pui8Data[24];
  
      //
      // The function that is called when the current request has completed
      // processing.
      //
      tSensorCallback *pfnCallback;
  
      //
      // The callback data provided to the callback function.
      //
      void *pvCallbackData;
  
      //
      // A union of structures that are used for read, write and
      // read-modify-write operations.  Since only one operation can be active at
      // a time, it is safe to re-use the memory in this manner.
      //
      union
      {
          //
          // A buffer used to store the write portion of a register read.
          //
          uint8_t pui8Buffer[6];
  
          //
          // The write state used to write register values.
          //
          tI2CMWrite8 sWriteState;
  
          //
          // The read-modify-write state used to modify register values.
          //
          tI2CMReadModifyWrite8 sReadModifyWriteState;
      }
      uCommand;
  }
  tMPU9150;
  
  //*****************************************************************************
  //
  // Function prototypes.
  //
  //*****************************************************************************
  extern uint_fast8_t MPU9150Init(tMPU9150 *psInst, tI2CMInstance *psI2CInst,
                                  uint_fast8_t ui8I2CAddr,
                                  tSensorCallback *pfnCallback,
                                  void *pvCallbackData);
  extern tAK8975 *MPU9150InstAK8975Get(tMPU9150 *psInst);
  extern uint_fast8_t MPU9150Read(tMPU9150 *psInst, uint_fast8_t ui8Reg,
                                  uint8_t *pui8Data, uint_fast16_t ui16Count,
                                  tSensorCallback *pfnCallback,
                                  void *pvCallbackData);
  extern uint_fast8_t MPU9150Write(tMPU9150 *psInst, uint_fast8_t ui8Reg,
                                   const uint8_t *pui8Data,
                                   uint_fast16_t ui16Count,
                                   tSensorCallback *pfnCallback,
                                   void *pvCallbackData);
  extern uint_fast8_t MPU9150ReadModifyWrite(tMPU9150 *psInst,
                                             uint_fast8_t ui8Reg,
                                             uint_fast8_t ui8Mask,
                                             uint_fast8_t ui8Value,
                                             tSensorCallback *pfnCallback,
                                             void *pvCallbackData);
  extern uint_fast8_t MPU9150DataRead(tMPU9150 *psInst,
                                      tSensorCallback *pfnCallback,
                                      void *pvCallbackData);
  extern void MPU9150DataAccelGetRaw(tMPU9150 *psInst,
                                     uint_fast16_t *pui16AccelX,
                                     uint_fast16_t *pui16AccelY,
                                     uint_fast16_t *pui16AccelZ);
  extern void MPU9150DataAccelGetFloat(tMPU9150 *psInst, float *pfAccelX,
                                       float *pfAccelY, float *pfAccelZ);
  extern void MPU9150DataGyroGetRaw(tMPU9150 *psInst, uint_fast16_t *pui16GyroX,
                                    uint_fast16_t *pui16GyroY,
                                    uint_fast16_t *pui16GyroZ);
  extern void MPU9150DataGyroGetFloat(tMPU9150 *psInst, float *pfGyroX,
                                      float *pfGyroY, float *pfGyroZ);
  extern void MPU9150DataMagnetoGetRaw(tMPU9150 *psInst,
                                       uint_fast16_t *pui16MagnetoX,
                                       uint_fast16_t *pui16MagnetoY,
                                       uint_fast16_t *pui16MagnetoZ);
  extern void MPU9150DataMagnetoGetFloat(tMPU9150 *psInst, float *pfMagnetoX,
                                         float *pfMagnetoY, float *pfMagnetoZ);
  
  //*****************************************************************************
  //
  // Mark the end of the C bindings section for C++ compilers.
  //
  //*****************************************************************************
  #ifdef __cplusplus
  }
  #endif
  
  #endif // __SENSORLIB_MPU9150_H__
  