/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
#ifndef __AP_INERTIAL_SENSOR_H__
#define __AP_INERTIAL_SENSOR_H__
#include "../AP_Math/AP_Math.h"
#include "../AP_PeriodicProcess/AP_PeriodicProcess.h"
#define GRAVITY 9.80665
// Gyro and Accelerometer calibration criteria
#define AP_INERTIAL_SENSOR_ACCEL_TOT_MAX_OFFSET_CHANGE 4.0
#define AP_INERTIAL_SENSOR_ACCEL_MAX_OFFSET 250.0
/* AP_InertialSensor is an abstraction for gyro and accel measurements
* which are correctly aligned to the body axes and scaled to SI units.
*/
class AP_InertialSensor
{
public:
AP_InertialSensor();
enum Start_style {
COLD_START = 0,
WARM_START
};
/// Perform startup initialisation.
///
/// Called to initialise the state of the IMU.
///
/// For COLD_START, implementations using real sensors can assume
/// that the airframe is stationary and nominally oriented.
///
/// For WARM_START, no assumptions should be made about the
/// orientation or motion of the airframe. Calibration should be
/// as for the previous COLD_START call.
///
/// @param style The initialisation startup style.
///
virtual void init( Start_style style,
void (*delay_cb)(unsigned long t),
void (*flash_leds_cb)(bool on),
AP_PeriodicProcess * scheduler );
/// Perform cold startup initialisation for just the accelerometers.
///
/// @note This should not be called unless ::init has previously
/// been called, as ::init may perform other work.
///
virtual void init_accel(void (*delay_cb)(unsigned long t), void (*flash_leds_cb)(bool on));
#if !defined( __AVR_ATmega1280__ )
// perform accelerometer calibration including providing user instructions and feedback
virtual bool calibrate_accel(void (*delay_cb)(unsigned long t),
void (*flash_leds_cb)(bool on),
void (*send_msg)(const prog_char_t *, ...),
void (*wait_key)(void));
#endif
/// Perform cold-start initialisation for just the gyros.
///
/// @note This should not be called unless ::init has previously
/// been called, as ::init may perform other work
///
virtual void init_gyro(void (*callback)(unsigned long t), void (*flash_leds_cb)(bool on));
/// Fetch the current gyro values
///
/// @returns vector of rotational rates in radians/sec
///
Vector3f get_gyro(void) { return _gyro; }
// set gyro offsets in radians/sec
Vector3f get_gyro_offsets(void) { return _gyro_offset; }
void set_gyro_offsets(Vector3f offsets) { _gyro_offset.set(offsets); }
/// Fetch the current accelerometer values
///
/// @returns vector of current accelerations in m/s/s
///
Vector3f get_accel(void) { return _accel; }
// get accel offsets in m/s/s
Vector3f get_accel_offsets() { return _accel_offset; }
void set_accel_offsets(Vector3f offsets) { _accel_offset.set(offsets); }
// get accel scale
Vector3f get_accel_scale() { return _accel_scale; }
/* Update the sensor data, so that getters are nonblocking.
* Returns a bool of whether data was updated or not.
*/
virtual bool update() = 0;
// check if the sensors have new data
virtual bool new_data_available(void) = 0;
/* Getters for individual gyro axes.
* Gyros have correct coordinate frame and units (degrees per second).
*/
virtual float gx() = 0;
virtual float gy() = 0;
virtual float gz() = 0;
/* Getters for individual accel axes.
* Accels have correct coordinate frame ( flat level ax, ay = 0; az = -9.81)
* and units (meters per second squared).
*/
virtual float ax() = 0;
virtual float ay() = 0;
virtual float az() = 0;
/* Temperature, in degrees celsius, of the gyro. */
virtual float temperature() = 0;
/* get_delta_time returns the time period in seconds
* overwhich the sensor data was collected
*/
virtual float get_delta_time() { return (float)get_delta_time_micros() * 1.0e-6; }
virtual uint32_t get_delta_time_micros() = 0;
// get_last_sample_time_micros returns the time in microseconds that the last sample was taken
//virtual uint32_t get_last_sample_time_micros() = 0;
// return the maximum gyro drift rate in radians/s/s. This
// depends on what gyro chips are being used
virtual float get_gyro_drift_rate(void) = 0;
// get number of samples read from the sensors
virtual uint16_t num_samples_available() = 0;
// class level parameters
static const struct AP_Param::GroupInfo var_info[];
protected:
// sensor specific init to be overwritten by descendant classes
virtual uint16_t _init_sensor( AP_PeriodicProcess * scheduler ) = 0;
// no-save implementations of accel and gyro initialisation routines
virtual void _init_accel(void (*delay_cb)(unsigned long t),
void (*flash_leds_cb)(bool on) = NULL);
virtual void _init_gyro(void (*delay_cb)(unsigned long t),
void (*flash_leds_cb)(bool on) = NULL);
#if !defined( __AVR_ATmega1280__ )
// _calibrate_accel - perform low level accel calibration
virtual bool _calibrate_accel(Vector3f accel_sample[6], Vector3f& accel_offsets, Vector3f& accel_scale);
virtual void _calibrate_update_matrices(float dS[6], float JS[6][6], float beta[6], float data[3]);
virtual void _calibrate_reset_matrices(float dS[6], float JS[6][6]);
virtual void _calibrate_find_delta(float dS[6], float JS[6][6], float delta[6]);
#endif
// save parameters to eeprom
void _save_parameters();
// Most recent accelerometer reading obtained by ::update
Vector3f _accel;
// Most recent gyro reading obtained by ::update
Vector3f _gyro;
// product id
AP_Int16 _product_id;
// accelerometer scaling and offsets
AP_Vector3f _accel_scale;
AP_Vector3f _accel_offset;
AP_Vector3f _gyro_offset;
};
#include "AP_InertialSensor_Oilpan.h"
#include "AP_InertialSensor_MPU6000.h"
#include "AP_InertialSensor_Stub.h"
#endif // __AP_INERTIAL_SENSOR_H__