PMW3901.hpp

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/**
 * @file PMW3901.hpp
 * @author Daniele Pettenuzzo
 *
 * Driver for the pmw3901 optical flow sensor connected via SPI.
 */

#include <px4_platform_common/px4_config.h>
#include <px4_platform_common/defines.h>
#include <px4_platform_common/getopt.h>
#include <px4_platform_common/px4_work_queue/ScheduledWorkItem.hpp>
#include <drivers/device/spi.h>
#include <conversion/rotation.h>
#include <lib/perf/perf_counter.h>
#include <lib/parameters/param.h>
#include <drivers/drv_hrt.h>
#include <uORB/PublicationMulti.hpp>
#include <uORB/topics/optical_flow.h>

/* Configuration Constants */

#if defined PX4_SPI_BUS_EXPANSION   // crazyflie
# define PMW3901_BUS PX4_SPI_BUS_EXPANSION
#elif defined PX4_SPI_BUS_EXTERNAL1   // fmu-v5
# define PMW3901_BUS PX4_SPI_BUS_EXTERNAL1
#elif defined PX4_SPI_BUS_EXTERNAL    // fmu-v4 extspi
# define PMW3901_BUS PX4_SPI_BUS_EXTERNAL
#else
# error "add the required spi bus from board_config.h here"
#endif

#if defined PX4_SPIDEV_EXPANSION_2    // crazyflie flow deck
# define PMW3901_SPIDEV PX4_SPIDEV_EXPANSION_2
#elif defined PX4_SPIDEV_EXTERNAL1_1    // fmu-v5 ext CS1
# define PMW3901_SPIDEV PX4_SPIDEV_EXTERNAL1_1
#elif defined PX4_SPIDEV_EXTERNAL   // fmu-v4 extspi
# define PMW3901_SPIDEV PX4_SPIDEV_EXTERNAL
#else
# error "add the required spi dev from board_config.h here"
#endif

#define PMW3901_SPI_BUS_SPEED (2000000L) // 2MHz

#define DIR_WRITE(a) ((a) | (1 << 7))
#define DIR_READ(a) ((a) & 0x7f)

#define PMW3901_DEVICE_PATH "/dev/pmw3901"

/* PMW3901 Registers addresses */
#define PMW3901_US 1000 /*   1 ms */
#define PMW3901_SAMPLE_INTERVAL 10000 /*  10 ms */


class PMW3901 : public device::SPI, public px4::ScheduledWorkItem
{
public:
    PMW3901(int bus = PMW3901_BUS, enum Rotation yaw_rotation = (enum Rotation)0);

    virtual ~PMW3901();

    virtual int init();

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

protected:
    virtual int probe();

private:

    const uint64_t _collect_time{15000}; // usecs, ensures flow data is published every second iteration of Run() (100Hz -> 50Hz)

    uORB::PublicationMulti<optical_flow_s> _optical_flow_pub{ORB_ID(optical_flow)};

    perf_counter_t _sample_perf;
    perf_counter_t _comms_errors;

    uint64_t _previous_collect_timestamp{0};

    enum Rotation _yaw_rotation;

    int _flow_sum_x{0};
    int _flow_sum_y{0};
    uint64_t _flow_dt_sum_usec{0};
    uint16_t _flow_quality_sum{0};
    uint8_t _flow_sample_counter{0};

    /**
    * Initialise 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.
    */
    void Run() override;

    int readRegister(unsigned reg, uint8_t *data, unsigned count);
    int writeRegister(unsigned reg, uint8_t data);

    int sensorInit();
    int readMotionCount(int16_t &deltaX, int16_t &deltaY, uint8_t &qual);
};