bmi160.cpp

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#include "bmi160.hpp"

/*
  list of registers that will be checked in check_registers(). Note
  that ADDR_WHO_AM_I must be first in the list.
 */
const uint8_t BMI160::_checked_registers[BMI160_NUM_CHECKED_REGISTERS] = {    BMIREG_CHIP_ID,
                                          BMIREG_ACC_CONF,
                                          BMIREG_ACC_RANGE,
                                          BMIREG_GYR_CONF,
                                          BMIREG_GYR_RANGE,
                                          BMIREG_INT_EN_1,
                                          BMIREG_INT_OUT_CTRL,
                                          BMIREG_INT_MAP_1,
                                          BMIREG_IF_CONF,
                                          BMIREG_NV_CONF
                                     };

BMI160::BMI160(int bus, uint32_t device, enum Rotation rotation) :
    SPI("BMI160", nullptr, bus, device, SPIDEV_MODE3, BMI160_BUS_SPEED),
    ScheduledWorkItem(MODULE_NAME, px4::device_bus_to_wq(this->get_device_id())),
    _px4_accel(get_device_id(), (external() ? ORB_PRIO_MAX - 1 : ORB_PRIO_HIGH - 1), rotation),
    _px4_gyro(get_device_id(), (external() ? ORB_PRIO_MAX - 1 : ORB_PRIO_HIGH - 1), rotation),
    _accel_reads(perf_alloc(PC_COUNT, "bmi160_accel_read")),
    _gyro_reads(perf_alloc(PC_COUNT, "bmi160_gyro_read")),
    _sample_perf(perf_alloc(PC_ELAPSED, "bmi160_read")),
    _bad_transfers(perf_alloc(PC_COUNT, "bmi160_bad_transfers")),
    _bad_registers(perf_alloc(PC_COUNT, "bmi160_bad_registers")),
    _good_transfers(perf_alloc(PC_COUNT, "bmi160_good_transfers")),
    _reset_retries(perf_alloc(PC_COUNT, "bmi160_reset_retries")),
    _duplicates(perf_alloc(PC_COUNT, "bmi160_duplicates"))
{
    _px4_accel.set_device_type(DRV_ACC_DEVTYPE_BMI160);
    _px4_accel.set_sample_rate(BMI160_ACCEL_DEFAULT_RATE);

    _px4_gyro.set_device_type(DRV_GYR_DEVTYPE_BMI160);
    _px4_accel.set_sample_rate(BMI160_GYRO_DEFAULT_RATE);
}

BMI160::~BMI160()
{
    /* make sure we are truly inactive */
    stop();

    /* delete the perf counter */
    perf_free(_sample_perf);
    perf_free(_accel_reads);
    perf_free(_gyro_reads);
    perf_free(_bad_transfers);
    perf_free(_bad_registers);
    perf_free(_good_transfers);
    perf_free(_reset_retries);
    perf_free(_duplicates);
}

int
BMI160::init()
{
    /* do SPI init (and probe) first */
    int ret = SPI::init();

    /* if probe/setup failed, bail now */
    if (ret != OK) {
        DEVICE_DEBUG("SPI setup failed");
        return ret;
    }

    ret = reset();

    if (ret != PX4_OK) {
        return ret;
    }

    start();

    return ret;
}

int BMI160::reset()
{
    write_reg(BMIREG_CONF, (1 << 1)); //Enable NVM programming

    write_checked_reg(BMIREG_ACC_CONF,      BMI_ACCEL_US | BMI_ACCEL_BWP_NORMAL); //Normal operation, no decimation
    write_checked_reg(BMIREG_ACC_RANGE,     0);
    write_checked_reg(BMIREG_GYR_CONF,      BMI_GYRO_BWP_NORMAL);   //Normal operation, no decimation
    write_checked_reg(BMIREG_GYR_RANGE,     0);
    write_checked_reg(BMIREG_INT_EN_1,      BMI_DRDY_INT_EN); //Enable DRDY interrupt
    write_checked_reg(BMIREG_INT_OUT_CTRL,  BMI_INT1_EN);   //Enable interrupts on pin INT1
    write_checked_reg(BMIREG_INT_MAP_1,     BMI_DRDY_INT1); //DRDY interrupt on pin INT1
    write_checked_reg(BMIREG_IF_CONF,       BMI_SPI_4_WIRE |
              BMI_AUTO_DIS_SEC); //Disable secondary interface; Work in SPI 4-wire mode
    write_checked_reg(BMIREG_NV_CONF,       BMI_SPI); //Disable I2C interface

    set_accel_range(BMI160_ACCEL_DEFAULT_RANGE_G);
    accel_set_sample_rate(BMI160_ACCEL_DEFAULT_RATE);

    set_gyro_range(BMI160_GYRO_DEFAULT_RANGE_DPS);
    gyro_set_sample_rate(BMI160_GYRO_DEFAULT_RATE);


    //_set_dlpf_filter(BMI160_ACCEL_DEFAULT_ONCHIP_FILTER_FREQ); //NOT CONSIDERING FILTERING YET

    //Enable Accelerometer in normal mode
    write_reg(BMIREG_CMD, BMI_ACCEL_NORMAL_MODE);
    up_udelay(4100);
    //usleep(4100);

    //Enable Gyroscope in normal mode
    write_reg(BMIREG_CMD, BMI_GYRO_NORMAL_MODE);
    up_udelay(80300);
    //usleep(80300);

    uint8_t retries = 10;

    while (retries--) {
        bool all_ok = true;

        for (uint8_t i = 0; i < BMI160_NUM_CHECKED_REGISTERS; i++) {
            if (read_reg(_checked_registers[i]) != _checked_values[i]) {
                write_reg(_checked_registers[i], _checked_values[i]);
                all_ok = false;
            }
        }

        if (all_ok) {
            break;
        }
    }

    _accel_reads = 0;
    _gyro_reads = 0;

    return OK;
}

int
BMI160::probe()
{
    /* look for device ID */
    _whoami = read_reg(BMIREG_CHIP_ID);

    // verify product revision
    switch (_whoami) {
    case BMI160_WHO_AM_I:
        memset(_checked_values, 0, sizeof(_checked_values));
        memset(_checked_bad, 0, sizeof(_checked_bad));
        _checked_values[0] = _whoami;
        _checked_bad[0] = _whoami;
        return OK;
    }

    DEVICE_DEBUG("unexpected whoami 0x%02x", _whoami);
    return -EIO;
}

int
BMI160::accel_set_sample_rate(float frequency)
{
    uint8_t setbits = 0;
    uint8_t clearbits = (BMI_ACCEL_RATE_25_8 | BMI_ACCEL_RATE_1600);

    if ((int)frequency == 0) {
        frequency = 1600;
    }

    if (frequency <= 25 / 32) {
        setbits |= BMI_ACCEL_RATE_25_32;
        _accel_sample_rate = 25 / 32;

    } else if (frequency <= 25 / 16) {
        setbits |= BMI_ACCEL_RATE_25_16;
        _accel_sample_rate = 25 / 16;

    } else if (frequency <= 25 / 8) {
        setbits |= BMI_ACCEL_RATE_25_8;
        _accel_sample_rate = 25 / 8;

    } else if (frequency <= 25 / 4) {
        setbits |= BMI_ACCEL_RATE_25_4;
        _accel_sample_rate = 25 / 4;

    } else if (frequency <= 25 / 2) {
        setbits |= BMI_ACCEL_RATE_25_2;
        _accel_sample_rate = 25 / 2;

    } else if (frequency <= 25) {
        setbits |= BMI_ACCEL_RATE_25;
        _accel_sample_rate = 25;

    } else if (frequency <= 50) {
        setbits |= BMI_ACCEL_RATE_50;
        _accel_sample_rate = 50;

    } else if (frequency <= 100) {
        setbits |= BMI_ACCEL_RATE_100;
        _accel_sample_rate = 100;

    } else if (frequency <= 200) {
        setbits |= BMI_ACCEL_RATE_200;
        _accel_sample_rate = 200;

    } else if (frequency <= 400) {
        setbits |= BMI_ACCEL_RATE_400;
        _accel_sample_rate = 400;

    } else if (frequency <= 800) {
        setbits |= BMI_ACCEL_RATE_800;
        _accel_sample_rate = 800;

    } else if (frequency > 800) {
        setbits |= BMI_ACCEL_RATE_1600;
        _accel_sample_rate = 1600;

    } else {
        return -EINVAL;
    }

    modify_reg(BMIREG_ACC_CONF, clearbits, setbits);

    return OK;
}

int
BMI160::gyro_set_sample_rate(float frequency)
{
    uint8_t setbits = 0;
    uint8_t clearbits = (BMI_GYRO_RATE_200 | BMI_GYRO_RATE_25);

    if ((int)frequency == 0) {
        frequency = 3200;
    }

    if (frequency <= 25) {
        setbits |= BMI_GYRO_RATE_25;
        _gyro_sample_rate = 25;

    } else if (frequency <= 50) {
        setbits |= BMI_GYRO_RATE_50;
        _gyro_sample_rate = 50;

    } else if (frequency <= 100) {
        setbits |= BMI_GYRO_RATE_100;
        _gyro_sample_rate = 100;

    } else if (frequency <= 200) {
        setbits |= BMI_GYRO_RATE_200;
        _gyro_sample_rate = 200;

    } else if (frequency <= 400) {
        setbits |= BMI_GYRO_RATE_400;
        _gyro_sample_rate = 400;

    } else if (frequency <= 800) {
        setbits |= BMI_GYRO_RATE_800;
        _gyro_sample_rate = 800;

    } else if (frequency <= 1600) {
        setbits |= BMI_GYRO_RATE_1600;
        _gyro_sample_rate = 1600;

    } else if (frequency > 1600) {
        setbits |= BMI_GYRO_RATE_3200;
        _gyro_sample_rate = 3200;

    } else {
        return -EINVAL;
    }

    modify_reg(BMIREG_GYR_CONF, clearbits, setbits);

    return OK;
}

void
BMI160::_set_dlpf_filter(uint16_t bandwidth)
{
    _dlpf_freq = 0;
    bandwidth = bandwidth;   //TO BE IMPLEMENTED
    /*uint8_t setbits = BW_SCAL_ODR_BW_XL;
    uint8_t clearbits = BW_XL_50_HZ;

    if (bandwidth == 0) {
        _dlpf_freq = 408;
        clearbits = BW_SCAL_ODR_BW_XL | BW_XL_50_HZ;
        setbits = 0;
    }

    if (bandwidth <= 50) {
        setbits |= BW_XL_50_HZ;
        _dlpf_freq = 50;

    } else if (bandwidth <= 105) {
        setbits |= BW_XL_105_HZ;
        _dlpf_freq = 105;

    } else if (bandwidth <= 211) {
        setbits |= BW_XL_211_HZ;
        _dlpf_freq = 211;

    } else if (bandwidth <= 408) {
        setbits |= BW_XL_408_HZ;
        _dlpf_freq = 408;

    }
    modify_reg(CTRL_REG6_XL, clearbits, setbits);*/
}

/*
  deliberately trigger an error in the sensor to trigger recovery
 */
void
BMI160::test_error()
{
    write_reg(BMIREG_CMD, BMI160_SOFT_RESET);
    ::printf("error triggered\n");
    print_registers();
}

uint8_t
BMI160::read_reg(unsigned reg)
{
    uint8_t cmd[2] = { (uint8_t)(reg | DIR_READ), 0};

    transfer(cmd, cmd, sizeof(cmd));

    return cmd[1];
}

uint16_t
BMI160::read_reg16(unsigned reg)
{
    uint8_t cmd[3] = { (uint8_t)(reg | DIR_READ), 0, 0 };

    transfer(cmd, cmd, sizeof(cmd));

    return (uint16_t)(cmd[1] << 8) | cmd[2];
}

void
BMI160::write_reg(unsigned reg, uint8_t value)
{
    uint8_t cmd[2];

    cmd[0] = reg | DIR_WRITE;
    cmd[1] = value;

    transfer(cmd, nullptr, sizeof(cmd));
}

void
BMI160::modify_reg(unsigned reg, uint8_t clearbits, uint8_t setbits)
{
    uint8_t val;

    val = read_reg(reg);
    val &= ~clearbits;
    val |= setbits;
    write_checked_reg(reg, val);
}

void
BMI160::write_checked_reg(unsigned reg, uint8_t value)
{
    write_reg(reg, value);

    for (uint8_t i = 0; i < BMI160_NUM_CHECKED_REGISTERS; i++) {
        if (reg == _checked_registers[i]) {
            _checked_values[i] = value;
            _checked_bad[i] = value;
        }
    }
}

int
BMI160::set_accel_range(unsigned max_g)
{
    uint8_t setbits = 0;
    uint8_t clearbits = BMI_ACCEL_RANGE_2_G | BMI_ACCEL_RANGE_16_G;
    float lsb_per_g;

    if (max_g == 0) {
        max_g = 16;
    }

    if (max_g <= 2) {
        //max_accel_g = 2;
        setbits |= BMI_ACCEL_RANGE_2_G;
        lsb_per_g = 16384;

    } else if (max_g <= 4) {
        //max_accel_g = 4;
        setbits |= BMI_ACCEL_RANGE_4_G;
        lsb_per_g = 8192;

    } else if (max_g <= 8) {
        //max_accel_g = 8;
        setbits |= BMI_ACCEL_RANGE_8_G;
        lsb_per_g = 4096;

    } else if (max_g <= 16) {
        //max_accel_g = 16;
        setbits |= BMI_ACCEL_RANGE_16_G;
        lsb_per_g = 2048;

    } else {
        return -EINVAL;
    }

    _px4_accel.set_scale(CONSTANTS_ONE_G / lsb_per_g);

    modify_reg(BMIREG_ACC_RANGE, clearbits, setbits);

    return OK;
}

int
BMI160::set_gyro_range(unsigned max_dps)
{
    uint8_t setbits = 0;
    uint8_t clearbits = BMI_GYRO_RANGE_125_DPS | BMI_GYRO_RANGE_250_DPS;
    float lsb_per_dps;
    //float max_gyro_dps;

    if (max_dps == 0) {
        max_dps = 2000;
    }

    if (max_dps <= 125) {
        //max_gyro_dps = 125;
        lsb_per_dps = 262.4;
        setbits |= BMI_GYRO_RANGE_125_DPS;

    } else if (max_dps <= 250) {
        //max_gyro_dps = 250;
        lsb_per_dps = 131.2;
        setbits |= BMI_GYRO_RANGE_250_DPS;

    } else if (max_dps <= 500) {
        //max_gyro_dps = 500;
        lsb_per_dps = 65.6;
        setbits |= BMI_GYRO_RANGE_500_DPS;

    } else if (max_dps <= 1000) {
        //max_gyro_dps = 1000;
        lsb_per_dps = 32.8;
        setbits |= BMI_GYRO_RANGE_1000_DPS;

    } else if (max_dps <= 2000) {
        //max_gyro_dps = 2000;
        lsb_per_dps = 16.4;
        setbits |= BMI_GYRO_RANGE_2000_DPS;

    } else {
        return -EINVAL;
    }

    _px4_gyro.set_scale(M_PI_F / (180.0f * lsb_per_dps));

    modify_reg(BMIREG_GYR_RANGE, clearbits, setbits);

    return OK;
}

void
BMI160::start()
{
    /* make sure we are stopped first */
    stop();

    /* start polling at the specified rate */
    ScheduleOnInterval((1_s / BMI160_GYRO_DEFAULT_RATE) - BMI160_TIMER_REDUCTION, 1000);

    reset();
}

void
BMI160::stop()
{
    ScheduleClear();
}

void
BMI160::Run()
{
    /* make another measurement */
    measure();
}

void
BMI160::check_registers(void)
{
    uint8_t v;

    if ((v = read_reg(_checked_registers[_checked_next])) !=
        _checked_values[_checked_next]) {
        _checked_bad[_checked_next] = v;

        /*
          if we get the wrong value then we know the SPI bus
          or sensor is very sick. We set _register_wait to 20
          and wait until we have seen 20 good values in a row
          before we consider the sensor to be OK again.
         */
        perf_count(_bad_registers);

        /*
          try to fix the bad register value. We only try to
          fix one per loop to prevent a bad sensor hogging the
          bus.
         */
        if (_register_wait == 0 || _checked_next == 0) {
            // if the product_id is wrong then reset the
            // sensor completely
            write_reg(BMIREG_CMD, BMI160_SOFT_RESET);
            _reset_wait = hrt_absolute_time() + 10000;
            _checked_next = 0;

        } else {
            write_reg(_checked_registers[_checked_next], _checked_values[_checked_next]);
            // waiting 3ms between register writes seems
            // to raise the chance of the sensor
            // recovering considerably
            _reset_wait = hrt_absolute_time() + 3000;
        }

        _register_wait = 20;
    }

    _checked_next = (_checked_next + 1) % BMI160_NUM_CHECKED_REGISTERS;
}

void
BMI160::measure()
{
    if (hrt_absolute_time() < _reset_wait) {
        // we're waiting for a reset to complete
        return;
    }

    struct BMIReport bmi_report {};

    struct Report {
        int16_t     accel_x;
        int16_t     accel_y;
        int16_t     accel_z;
        int16_t     temp;
        int16_t     gyro_x;
        int16_t     gyro_y;
        int16_t     gyro_z;
    } report;

    /* start measuring */
    perf_begin(_sample_perf);

    /*
     * Fetch the full set of measurements from the BMI160 in one pass.
     */
    bmi_report.cmd = BMIREG_GYR_X_L | DIR_READ;

    uint8_t     status = read_reg(BMIREG_STATUS);

    const hrt_abstime timestamp_sample = hrt_absolute_time();

    if (OK != transfer((uint8_t *)&bmi_report, ((uint8_t *)&bmi_report), sizeof(bmi_report))) {
        return;
    }

    check_registers();

    if ((!(status & (0x80))) && (!(status & (0x04)))) {
        perf_end(_sample_perf);
        perf_count(_duplicates);
        _got_duplicate = true;
        return;
    }

    _last_accel[0] = bmi_report.accel_x;
    _last_accel[1] = bmi_report.accel_y;
    _last_accel[2] = bmi_report.accel_z;
    _got_duplicate = false;

    uint8_t temp_l = read_reg(BMIREG_TEMP_0);
    uint8_t temp_h = read_reg(BMIREG_TEMP_1);

    report.temp = ((temp_h << 8) + temp_l);



    report.accel_x = bmi_report.accel_x;
    report.accel_y = bmi_report.accel_y;
    report.accel_z = bmi_report.accel_z;

    report.gyro_x = bmi_report.gyro_x;
    report.gyro_y = bmi_report.gyro_y;
    report.gyro_z = bmi_report.gyro_z;

    if (report.accel_x == 0 &&
        report.accel_y == 0 &&
        report.accel_z == 0 &&
        report.temp == 0 &&
        report.gyro_x == 0 &&
        report.gyro_y == 0 &&
        report.gyro_z == 0) {

        // all zero data - probably a SPI bus error
        perf_count(_bad_transfers);
        perf_end(_sample_perf);
        // note that we don't call reset() here as a reset()
        // costs 20ms with interrupts disabled. That means if
        // the bmi160 does go bad it would cause a FMU failure,
        // regardless of whether another sensor is available,
        return;
    }

    perf_count(_good_transfers);

    if (_register_wait != 0) {
        // we are waiting for some good transfers before using
        // the sensor again. We still increment
        // _good_transfers, but don't return any data yet
        _register_wait--;
        return;
    }

    // report the error count as the sum of the number of bad
    // transfers and bad register reads. This allows the higher
    // level code to decide if it should use this sensor based on
    // whether it has had failures
    const uint64_t error_count = perf_event_count(_bad_transfers) + perf_event_count(_bad_registers);
    _px4_accel.set_error_count(error_count);
    _px4_gyro.set_error_count(error_count);

    const float temperature = 23.0f + report.temp * 1.0f / 512.0f;
    _px4_accel.set_temperature(temperature);
    _px4_gyro.set_temperature(temperature);

    /*
     * 1) Scale raw value to SI units using scaling from datasheet.
     * 2) Subtract static offset (in SI units)
     * 3) Scale the statically calibrated values with a linear
     *    dynamically obtained factor
     *
     * Note: the static sensor offset is the number the sensor outputs
     *   at a nominally 'zero' input. Therefore the offset has to
     *   be subtracted.
     *
     *   Example: A gyro outputs a value of 74 at zero angular rate
     *        the offset is 74 from the origin and subtracting
     *        74 from all measurements centers them around zero.
     */


    /* NOTE: Axes have been swapped to match the board a few lines above. */

    _px4_accel.update(timestamp_sample, bmi_report.accel_x, bmi_report.accel_y, bmi_report.accel_z);
    _px4_gyro.update(timestamp_sample, bmi_report.gyro_x, bmi_report.gyro_y, bmi_report.gyro_z);

    /* stop measuring */
    perf_end(_sample_perf);
}

void
BMI160::print_info()
{
    perf_print_counter(_sample_perf);
    perf_print_counter(_accel_reads);
    perf_print_counter(_gyro_reads);
    perf_print_counter(_bad_transfers);
    perf_print_counter(_bad_registers);
    perf_print_counter(_good_transfers);
    perf_print_counter(_reset_retries);
    perf_print_counter(_duplicates);

    ::printf("checked_next: %u\n", _checked_next);

    for (uint8_t i = 0; i < BMI160_NUM_CHECKED_REGISTERS; i++) {
        uint8_t v = read_reg(_checked_registers[i]);

        if (v != _checked_values[i]) {
            ::printf("reg %02x:%02x should be %02x\n",
                 (unsigned)_checked_registers[i],
                 (unsigned)v,
                 (unsigned)_checked_values[i]);
        }

        if (v != _checked_bad[i]) {
            ::printf("reg %02x:%02x was bad %02x\n",
                 (unsigned)_checked_registers[i],
                 (unsigned)v,
                 (unsigned)_checked_bad[i]);
        }
    }

    _px4_accel.print_status();
    _px4_gyro.print_status();
}

void
BMI160::print_registers()
{
    printf("BMI160 registers\n");

    for (uint8_t reg = 0x40; reg <= 0x47; reg++) {
        uint8_t v = read_reg(reg);
        printf("%02x:%02x ", (unsigned)reg, (unsigned)v);

        if (reg % 13 == 0) {
            printf("\n");
        }
    }

    printf("\n");
}