MS5611.hpp 5.84 KB
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#pragma once

#include <drivers/device/device.h>
#include <lib/drivers/barometer/PX4Barometer.hpp>
#include <lib/perf/perf_counter.h>
#include <px4_platform_common/i2c_spi_buses.h>
#include <px4_platform_common/px4_work_queue/ScheduledWorkItem.hpp>
#include <systemlib/err.h>

#include "ms5611.h"

enum MS56XX_DEVICE_TYPES {
	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 */

class MS5611 : public I2CSPIDriver<MS5611>
{
public:
	MS5611(device::Device *interface, ms5611::prom_u &prom_buf, enum MS56XX_DEVICE_TYPES device_type,
	       I2CSPIBusOption bus_option, int bus);
	~MS5611() override;

	static I2CSPIDriverBase *instantiate(const BusCLIArguments &cli, const BusInstanceIterator &iterator,
					     int runtime_instance);
	static void print_usage();

	int		init();

	/**
	 * 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			RunImpl();

protected:
	void print_status() override;

	PX4Barometer		_px4_barometer;

	device::Device		*_interface;

	ms5611::prom_s		_prom;

	enum MS56XX_DEVICE_TYPES _device_type;
	bool			_collect_phase{false};
	unsigned		_measure_phase{false};

	/* intermediate temperature values per MS5611/MS5607 datasheet */
	int64_t			_OFF{0};
	int64_t			_SENS{0};

	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();

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

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