ardupilot/libraries/AP_InertialSensor/AP_InertialSensor_MPU6000.h

/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-

#ifndef __AP_INERTIAL_SENSOR_MPU6000_H__
#define __AP_INERTIAL_SENSOR_MPU6000_H__

#include <string.h>
#include <stdint.h>

#include "../AP_PeriodicProcess/AP_PeriodicProcess.h"
#include "../AP_Math/AP_Math.h"
#include "AP_InertialSensor.h"

#define DMP_FIFO_BUFFER_SIZE 72        // DMP FIFO buffer size

// DMP memory
extern const uint8_t dmpMem[8][16][16] PROGMEM;

class AP_InertialSensor_MPU6000 : public AP_InertialSensor
{
  public:

  AP_InertialSensor_MPU6000( uint8_t cs_pin );

  uint16_t init( AP_PeriodicProcess * scheduler );
  static void dmp_init();       // Initialise MPU6000's DMP
  static void dmp_reset();		// Reset the DMP (required for changes in gains or offsets to take effect)

  /* Concrete implementation of AP_InertialSensor functions: */
  bool update();
  bool new_data_available();
  float gx();
  float gy();
  float gz();
  void get_gyros( float * );
  float ax();
  float ay();
  float az();
  void get_accels( float * );
  void get_sensors( float * );
  float temperature();
  uint32_t sample_time();
  void reset_sample_time();
  float get_gyro_drift_rate();

  // set_gyro_offsets - updates gyro offsets in mpu6000 registers
  static void set_gyro_offsets_scaled(float offX, float offY, float offZ);
  static void set_gyro_offsets(int16_t offsetX, int16_t offsetY, int16_t offsetZ);

  // set_accel_offsets - updates accel offsets in DMP registers
  static void set_accel_offsets_scaled(float offX, float offY, float offZ);
  static void set_accel_offsets(int16_t offsetX, int16_t offsetY, int16_t offsetZ);

  private:

  static void read(uint32_t);
  static void data_interrupt(void);
  static uint8_t register_read( uint8_t reg );
  static void register_write( uint8_t reg, uint8_t val );
  static void hardware_init();

  Vector3f _gyro;
  Vector3f _accel;
  float _temp;

  uint32_t _last_sample_micros;

  float _temp_to_celsius( uint16_t );

  static const float _accel_scale;
  static const float _gyro_scale;

  static const uint8_t _gyro_data_index[3];
  static const  int8_t _gyro_data_sign[3];

  static const uint8_t _accel_data_index[3];
  static const  int8_t _accel_data_sign[3];

  static const uint8_t _temp_data_index;

  /* TODO deprecate _cs_pin */
  static uint8_t _cs_pin;

  // ensure we can't initialise twice
  bool _initialised;

  // dmp related methods and parameters
  static void dmp_register_write(uint8_t bank, uint8_t address, uint8_t num_bytes, uint8_t data[]);  // Method to write multiple bytes into dmp registers.  Requires a "bank" 
  static void dmp_set_rate(uint8_t rate);  // set DMP output rate (see constants)

public:
  static Quaternion quaternion;				// holds the 4 quaternions representing attitude taken directly from the DMP

  static bool FIFO_ready();					// returns true if new attitude data is available in FIFO buffer
  static void FIFO_reset();					// clear attitude data from FIFO buffer
  static void FIFO_getPacket();				// get latest attitude data from FIFO buffer
  static void dmp_set_gyro_calibration();
  static void dmp_set_accel_calibration();
  static void dmp_apply_endian_accel();
  static void dmp_set_mpu_sensors();			// To configure for SIX_AXIS output
  static void dmp_set_bias_from_no_motion();	// Turn on bias from no motion
  static void dmp_set_bias_none();				// Turn off internal bias correction (we will use this and we handle the gyro bias correction externally)
  static void dmp_set_fifo_interrupt();
  static void dmp_send_quaternion();			// Send quaternion data to FIFO
  static void dmp_send_gyro();					// Send gyro data to FIFO
  static void dmp_send_accel();				// Send accel data to FIFO
  static void dmp_set_fifo_rate(uint8_t rate);	// This functions defines the rate at wich attitude data is send to FIFO.  Rate: 0 => SAMPLE_RATE(ex:200Hz), 1=> SAMPLE_RATE/2 (ex:100Hz), 2=> SAMPLE_RATE/3 (ex:66Hz)
  static void dmp_set_sensor_fusion_accel_gain(uint8_t gain);	// This function defines the weight of the accel on the sensor fusion. Default value is 0x80. The official invensense name is inv_key_0_96 (?)
  static void dmp_load_mem();					// Load initial memory values into DMP memory banks

  static uint8_t _received_packet[DMP_FIFO_BUFFER_SIZE];    // FIFO packet buffer
  static uint8_t _fifoCountH;					// high byte of number of elements in fifo buffer
  static uint8_t _fifoCountL;					// low byte of number of elements in fifo buffer

  static bool _dmp_initialised;
};

#endif // __AP_INERTIAL_SENSOR_MPU6000_H__