LSM303D.hpp

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/**
 * @file LSM303D.hpp
 * Driver for the ST LSM303D MEMS accelerometer / magnetometer connected via SPI.
 */

#pragma once

#include <drivers/device/spi.h>
#include <ecl/geo/geo.h>
#include <perf/perf_counter.h>
#include <px4_platform_common/px4_work_queue/ScheduledWorkItem.hpp>
#include <lib/drivers/accelerometer/PX4Accelerometer.hpp>
#include <lib/drivers/magnetometer/PX4Magnetometer.hpp>

/* SPI protocol address bits */
#define DIR_READ            (1<<7)
#define DIR_WRITE           (0<<7)
#define ADDR_INCREMENT          (1<<6)

/* register addresses: A: accel, M: mag, T: temp */
#define ADDR_WHO_AM_I           0x0F
#define WHO_I_AM            0x49

#define ADDR_OUT_TEMP_L         0x05

#define ADDR_STATUS_A           0x27

#define ADDR_CTRL_REG0          0x1F
#define ADDR_CTRL_REG1          0x20
#define ADDR_CTRL_REG2          0x21
#define ADDR_CTRL_REG3          0x22
#define ADDR_CTRL_REG4          0x23
#define ADDR_CTRL_REG5          0x24
#define ADDR_CTRL_REG6          0x25
#define ADDR_CTRL_REG7          0x26

#define REG1_RATE_BITS_A        ((1<<7) | (1<<6) | (1<<5) | (1<<4))
#define REG1_POWERDOWN_A        ((0<<7) | (0<<6) | (0<<5) | (0<<4))
#define REG1_RATE_3_125HZ_A     ((0<<7) | (0<<6) | (0<<5) | (1<<4))
#define REG1_RATE_6_25HZ_A      ((0<<7) | (0<<6) | (1<<5) | (0<<4))
#define REG1_RATE_12_5HZ_A      ((0<<7) | (0<<6) | (1<<5) | (1<<4))
#define REG1_RATE_25HZ_A        ((0<<7) | (1<<6) | (0<<5) | (0<<4))
#define REG1_RATE_50HZ_A        ((0<<7) | (1<<6) | (0<<5) | (1<<4))
#define REG1_RATE_100HZ_A       ((0<<7) | (1<<6) | (1<<5) | (0<<4))
#define REG1_RATE_200HZ_A       ((0<<7) | (1<<6) | (1<<5) | (1<<4))
#define REG1_RATE_400HZ_A       ((1<<7) | (0<<6) | (0<<5) | (0<<4))
#define REG1_RATE_800HZ_A       ((1<<7) | (0<<6) | (0<<5) | (1<<4))
#define REG1_RATE_1600HZ_A      ((1<<7) | (0<<6) | (1<<5) | (0<<4))

#define REG1_BDU_UPDATE         (1<<3)
#define REG1_Z_ENABLE_A         (1<<2)
#define REG1_Y_ENABLE_A         (1<<1)
#define REG1_X_ENABLE_A         (1<<0)

#define REG2_ANTIALIAS_FILTER_BW_BITS_A ((1<<7) | (1<<6))
#define REG2_AA_FILTER_BW_773HZ_A       ((0<<7) | (0<<6))
#define REG2_AA_FILTER_BW_194HZ_A       ((0<<7) | (1<<6))
#define REG2_AA_FILTER_BW_362HZ_A       ((1<<7) | (0<<6))
#define REG2_AA_FILTER_BW_50HZ_A        ((1<<7) | (1<<6))

#define REG2_FULL_SCALE_BITS_A  ((1<<5) | (1<<4) | (1<<3))
#define REG2_FULL_SCALE_2G_A    ((0<<5) | (0<<4) | (0<<3))
#define REG2_FULL_SCALE_4G_A    ((0<<5) | (0<<4) | (1<<3))
#define REG2_FULL_SCALE_6G_A    ((0<<5) | (1<<4) | (0<<3))
#define REG2_FULL_SCALE_8G_A    ((0<<5) | (1<<4) | (1<<3))
#define REG2_FULL_SCALE_16G_A   ((1<<5) | (0<<4) | (0<<3))

#define REG5_ENABLE_T           (1<<7)

#define REG5_RES_HIGH_M         ((1<<6) | (1<<5))
#define REG5_RES_LOW_M          ((0<<6) | (0<<5))

#define REG5_RATE_BITS_M        ((1<<4) | (1<<3) | (1<<2))
#define REG5_RATE_3_125HZ_M     ((0<<4) | (0<<3) | (0<<2))
#define REG5_RATE_6_25HZ_M      ((0<<4) | (0<<3) | (1<<2))
#define REG5_RATE_12_5HZ_M      ((0<<4) | (1<<3) | (0<<2))
#define REG5_RATE_25HZ_M        ((0<<4) | (1<<3) | (1<<2))
#define REG5_RATE_50HZ_M        ((1<<4) | (0<<3) | (0<<2))
#define REG5_RATE_100HZ_M       ((1<<4) | (0<<3) | (1<<2))
#define REG5_RATE_DO_NOT_USE_M  ((1<<4) | (1<<3) | (0<<2))

#define REG6_FULL_SCALE_BITS_M  ((1<<6) | (1<<5))
#define REG6_FULL_SCALE_2GA_M   ((0<<6) | (0<<5))
#define REG6_FULL_SCALE_4GA_M   ((0<<6) | (1<<5))
#define REG6_FULL_SCALE_8GA_M   ((1<<6) | (0<<5))
#define REG6_FULL_SCALE_12GA_M  ((1<<6) | (1<<5))

#define REG7_CONT_MODE_M        ((0<<1) | (0<<0))

#define REG_STATUS_A_NEW_ZYXADA     0x08

/* default values for this device */
#define LSM303D_ACCEL_DEFAULT_RANGE_G           16
#define LSM303D_ACCEL_DEFAULT_RATE          800
#define LSM303D_ACCEL_DEFAULT_ONCHIP_FILTER_FREQ    50

#define LSM303D_MAG_DEFAULT_RANGE_GA            2
#define LSM303D_MAG_DEFAULT_RATE            100

/*
  we set the timer interrupt to run a bit faster than the desired
  sample rate and then throw away duplicates using the data ready bit.
  This time reduction is enough to cope with worst case timing jitter
  due to other timers
 */
#define LSM303D_TIMER_REDUCTION             200

extern "C" { __EXPORT int lsm303d_main(int argc, char *argv[]); }

class LSM303D : public device::SPI, public px4::ScheduledWorkItem
{
public:
    LSM303D(int bus, uint32_t device, enum Rotation rotation);
    virtual ~LSM303D();

    int     init() override;

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

protected:
    virtual int     probe();

private:

    void            Run() override;

    void            start();
    void            stop();
    void            reset();

    /**
     * disable I2C on the chip
     */
    void            disable_i2c();

    /**
     * check key registers for correct values
     */
    void            check_registers(void);

    /**
     * Fetch accel measurements from the sensor and update the report ring.
     */
    void            measureAccelerometer();

    /**
     * Fetch mag measurements from the sensor and update the report ring.
     */
    void            measureMagnetometer();

    /**
     * Read a register from the LSM303D
     *
     * @param       The register to read.
     * @return      The value that was read.
     */
    uint8_t         read_reg(unsigned reg);

    /**
     * Write a register in the LSM303D
     *
     * @param reg       The register to write.
     * @param value     The new value to write.
     */
    void            write_reg(unsigned reg, uint8_t value);

    /**
     * Modify a register in the LSM303D
     *
     * Bits are cleared before bits are set.
     *
     * @param reg       The register to modify.
     * @param clearbits Bits in the register to clear.
     * @param setbits   Bits in the register to set.
     */
    void            modify_reg(unsigned reg, uint8_t clearbits, uint8_t setbits);

    /**
     * Write a register in the LSM303D, updating _checked_values
     *
     * @param reg       The register to write.
     * @param value     The new value to write.
     */
    void            write_checked_reg(unsigned reg, uint8_t value);

    /**
     * Set the LSM303D accel measurement range.
     *
     * @param max_g The measurement range of the accel is in g (9.81m/s^2)
     *          Zero selects the maximum supported range.
     * @return      OK if the value can be supported, -ERANGE otherwise.
     */
    int         accel_set_range(unsigned max_g);

    /**
     * Set the LSM303D mag measurement range.
     *
     * @param max_ga    The measurement range of the mag is in Ga
     *          Zero selects the maximum supported range.
     * @return      OK if the value can be supported, -ERANGE otherwise.
     */
    int         mag_set_range(unsigned max_g);

    /**
     * Set the LSM303D on-chip anti-alias filter bandwith.
     *
     * @param bandwidth The anti-alias filter bandwidth in Hz
     *          Zero selects the highest bandwidth
     * @return      OK if the value can be supported, -ERANGE otherwise.
     */
    int         accel_set_onchip_lowpass_filter_bandwidth(unsigned bandwidth);

    /**
     * Set the LSM303D internal accel sampling frequency.
     *
     * @param frequency The internal accel sampling frequency is set to not less than
     *          this value.
     *          Zero selects the maximum rate supported.
     * @return      OK if the value can be supported.
     */
    int         accel_set_samplerate(unsigned frequency);

    /**
     * Set the LSM303D internal mag sampling frequency.
     *
     * @param frequency The internal mag sampling frequency is set to not less than
     *          this value.
     *          Zero selects the maximum rate supported.
     * @return      OK if the value can be supported.
     */
    int         mag_set_samplerate(unsigned frequency);


    PX4Accelerometer    _px4_accel;
    PX4Magnetometer     _px4_mag;

    unsigned        _call_accel_interval{1000000 / LSM303D_ACCEL_DEFAULT_RATE};
    unsigned        _call_mag_interval{1000000 / LSM303D_MAG_DEFAULT_RATE};

    perf_counter_t      _accel_sample_perf;
    perf_counter_t      _mag_sample_perf;
    perf_counter_t      _bad_registers;
    perf_counter_t      _bad_values;
    perf_counter_t      _accel_duplicates;

    uint8_t         _register_wait{0};

    int16_t         _last_accel[3] {};
    uint8_t         _constant_accel_count{0};

    hrt_abstime     _mag_last_measure{0};

    float           _last_temperature{0.0f};

    // this is used to support runtime checking of key
    // configuration registers to detect SPI bus errors and sensor
    // reset
    static constexpr int    LSM303D_NUM_CHECKED_REGISTERS{8};
    uint8_t         _checked_values[LSM303D_NUM_CHECKED_REGISTERS] {};
    uint8_t         _checked_next{0};

};