MS5611.hpp

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#pragma once

#include <drivers/device/i2c.h>
#include <drivers/device/device.h>
#include <drivers/device/ringbuffer.h>
#include <drivers/device/spi.h>
#include <drivers/drv_baro.h>
#include <lib/cdev/CDev.hpp>
#include <lib/perf/perf_counter.h>
#include <px4_platform_common/getopt.h>
#include <px4_platform_common/px4_work_queue/ScheduledWorkItem.hpp>
#include <systemlib/err.h>
#include <uORB/uORB.h>

#include "ms5611.h"

enum MS56XX_DEVICE_TYPES {
    MS56XX_DEVICE   = 0,
    MS5611_DEVICE   = 5611,
    MS5607_DEVICE   = 5607,
};

/* helper macro for handling report buffer indices */
#define INCREMENT(_x, _lim) do { __typeof__(_x) _tmp = _x+1; if (_tmp >= _lim) _tmp = 0; _x = _tmp; } while(0)

/* helper macro for arithmetic - returns the square of the argument */
#define POW2(_x)        ((_x) * (_x))

/*
 * MS5611/MS5607 internal constants and data structures.
 */
#define ADDR_CMD_CONVERT_D1_OSR256      0x40    /* write to this address to start pressure conversion */
#define ADDR_CMD_CONVERT_D1_OSR512      0x42    /* write to this address to start pressure conversion */
#define ADDR_CMD_CONVERT_D1_OSR1024     0x44    /* write to this address to start pressure conversion */
#define ADDR_CMD_CONVERT_D1_OSR2048     0x46    /* write to this address to start pressure conversion */
#define ADDR_CMD_CONVERT_D1_OSR4096     0x48    /* write to this address to start pressure conversion */
#define ADDR_CMD_CONVERT_D2_OSR256      0x50    /* write to this address to start temperature conversion */
#define ADDR_CMD_CONVERT_D2_OSR512      0x52    /* write to this address to start temperature conversion */
#define ADDR_CMD_CONVERT_D2_OSR1024     0x54    /* write to this address to start temperature conversion */
#define ADDR_CMD_CONVERT_D2_OSR2048     0x56    /* write to this address to start temperature conversion */
#define ADDR_CMD_CONVERT_D2_OSR4096     0x58    /* write to this address to start temperature conversion */

/*
  use an OSR of 1024 to reduce the self-heating effect of the
  sensor. Information from MS tells us that some individual sensors
  are quite sensitive to this effect and that reducing the OSR can
  make a big difference
 */
#define ADDR_CMD_CONVERT_D1         ADDR_CMD_CONVERT_D1_OSR1024
#define ADDR_CMD_CONVERT_D2         ADDR_CMD_CONVERT_D2_OSR1024

/*
 * Maximum internal conversion time for OSR 1024 is 2.28 ms. We set an update
 * rate of 100Hz which is be very safe not to read the ADC before the
 * conversion finished
 */
#define MS5611_CONVERSION_INTERVAL  10000   /* microseconds */
#define MS5611_MEASUREMENT_RATIO    3   /* pressure measurements per temperature measurement */
#define MS5611_BARO_DEVICE_PATH_EXT "/dev/ms5611_ext"
#define MS5611_BARO_DEVICE_PATH_INT "/dev/ms5611_int"

class MS5611 : public cdev::CDev, public px4::ScheduledWorkItem
{
public:
    MS5611(device::Device *interface, ms5611::prom_u &prom_buf, const char *path, enum MS56XX_DEVICE_TYPES device_type);
    ~MS5611();

    virtual int     init();

    virtual ssize_t     read(cdev::file_t *filp, char *buffer, size_t buflen);
    virtual int     ioctl(cdev::file_t *filp, int cmd, unsigned long arg);

    /**
     * Diagnostics - print some basic information about the driver.
     */
    void            print_info();

protected:
    device::Device      *_interface;

    ms5611::prom_s      _prom;

    unsigned        _measure_interval{0};

    ringbuffer::RingBuffer  *_reports;
    enum MS56XX_DEVICE_TYPES _device_type;
    bool            _collect_phase;
    unsigned        _measure_phase;

    /* intermediate temperature values per MS5611/MS5607 datasheet */
    int32_t         _TEMP;
    int64_t         _OFF;
    int64_t         _SENS;
    float           _P;
    float           _T;

    orb_advert_t        _baro_topic;
    int         _orb_class_instance;
    int         _class_instance;

    perf_counter_t      _sample_perf;
    perf_counter_t      _measure_perf;
    perf_counter_t      _comms_errors;

    /**
     * Initialize the automatic measurement state machine and start it.
     *
     * @note This function is called at open and error time.  It might make sense
     *       to make it more aggressive about resetting the bus in case of errors.
     */
    void            start();

    /**
     * Stop the automatic measurement state machine.
     */
    void            stop();

    /**
     * Perform a poll cycle; collect from the previous measurement
     * and start a new one.
     *
     * This is the heart of the measurement state machine.  This function
     * alternately starts a measurement, or collects the data from the
     * previous measurement.
     *
     * When the interval between measurements is greater than the minimum
     * measurement interval, a gap is inserted between collection
     * and measurement to provide the most recent measurement possible
     * at the next interval.
     */
    void            Run() override;

    /**
     * Issue a measurement command for the current state.
     *
     * @return      OK if the measurement command was successful.
     */
    virtual int     measure();

    /**
     * Collect the result of the most recent measurement.
     */
    virtual int     collect();
};