df_hmc5883_wrapper.cpp

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/**
 * @file df_hmc5883_wrapper.cpp
 * Lightweight driver to access the HMC5883 of the DriverFramework.
 *
 * @author Julian Oes <julian@oes.ch>
 */

#include <px4_platform_common/px4_config.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <unistd.h>
#include <px4_platform_common/getopt.h>
#include <errno.h>
#include <lib/parameters/param.h>
#include <perf/perf_counter.h>
#include <systemlib/err.h>

#include <drivers/drv_mag.h>
#include <drivers/drv_hrt.h>

#include <uORB/topics/parameter_update.h>

#include <board_config.h>

#include <lib/conversion/rotation.h>

#include <hmc5883/HMC5883.hpp>
#include <DevMgr.hpp>


extern "C" { __EXPORT int df_hmc5883_wrapper_main(int argc, char *argv[]); }

using namespace DriverFramework;


class DfHmc5883Wrapper : public HMC5883
{
public:
    DfHmc5883Wrapper(enum Rotation rotation, const char *path);
    ~DfHmc5883Wrapper();


    /**
     * Start automatic measurement.
     *
     * @return 0 on success
     */
    int     start();

    /**
     * Stop automatic measurement.
     *
     * @return 0 on success
     */
    int     stop();

private:
    int _publish(struct mag_sensor_data &data);

    void _update_mag_calibration();

    orb_advert_t        _mag_topic;

    int         _param_update_sub;

    struct mag_calibration_s {
        float x_offset;
        float x_scale;
        float y_offset;
        float y_scale;
        float z_offset;
        float z_scale;
    } _mag_calibration;

    matrix::Dcmf      _rotation_matrix;

    int         _mag_orb_class_instance;

    perf_counter_t      _mag_sample_perf;

};

DfHmc5883Wrapper::DfHmc5883Wrapper(enum Rotation rotation, const char *path) :
    HMC5883(path),
    _mag_topic(nullptr),
    _param_update_sub(-1),
    _mag_calibration{},
    _mag_orb_class_instance(-1),
    _mag_sample_perf(perf_alloc(PC_ELAPSED, "df_mag_read"))
{
    // Set sane default calibration values
    _mag_calibration.x_scale = 1.0f;
    _mag_calibration.y_scale = 1.0f;
    _mag_calibration.z_scale = 1.0f;
    _mag_calibration.x_offset = 0.0f;
    _mag_calibration.y_offset = 0.0f;
    _mag_calibration.z_offset = 0.0f;

    // Get sensor rotation matrix
    _rotation_matrix = get_rot_matrix(rotation);
}

DfHmc5883Wrapper::~DfHmc5883Wrapper()
{
    perf_free(_mag_sample_perf);
}

int DfHmc5883Wrapper::start()
{
    /* Subscribe to param update topic. */
    if (_param_update_sub < 0) {
        _param_update_sub = orb_subscribe(ORB_ID(parameter_update));
    }

    /* Init device and start sensor. */
    int ret = init();

    if (ret != 0) {
        PX4_ERR("HMC5883 init fail: %d", ret);
        return ret;
    }

    ret = HMC5883::start();

    if (ret != 0) {
        PX4_ERR("HMC5883 start fail: %d", ret);
        return ret;
    }

    /* Force getting the calibration values. */
    _update_mag_calibration();

    return 0;
}

int DfHmc5883Wrapper::stop()
{
    /* Stop sensor. */
    int ret = HMC5883::stop();

    if (ret != 0) {
        PX4_ERR("HMC5883 stop fail: %d", ret);
        return ret;
    }

    return 0;
}

void DfHmc5883Wrapper::_update_mag_calibration()
{
    // TODO: replace magic number
    for (unsigned i = 0; i < 3; ++i) {

        // TODO: remove printfs and add error counter

        char str[30];
        (void)sprintf(str, "CAL_MAG%u_ID", i);
        int32_t device_id;
        int res = param_get(param_find(str), &device_id);

        if (res != OK) {
            PX4_ERR("Could not access param %s", str);
            continue;
        }

        if ((uint32_t)device_id != m_id.dev_id) {
            continue;
        }

        (void)sprintf(str, "CAL_MAG%u_XSCALE", i);
        res = param_get(param_find(str), &_mag_calibration.x_scale);

        if (res != OK) {
            PX4_ERR("Could not access param %s", str);
        }

        (void)sprintf(str, "CAL_MAG%u_YSCALE", i);
        res = param_get(param_find(str), &_mag_calibration.y_scale);

        if (res != OK) {
            PX4_ERR("Could not access param %s", str);
        }

        (void)sprintf(str, "CAL_MAG%u_ZSCALE", i);
        res = param_get(param_find(str), &_mag_calibration.z_scale);

        if (res != OK) {
            PX4_ERR("Could not access param %s", str);
        }

        (void)sprintf(str, "CAL_MAG%u_XOFF", i);
        res = param_get(param_find(str), &_mag_calibration.x_offset);

        if (res != OK) {
            PX4_ERR("Could not access param %s", str);
        }

        (void)sprintf(str, "CAL_MAG%u_YOFF", i);
        res = param_get(param_find(str), &_mag_calibration.y_offset);

        if (res != OK) {
            PX4_ERR("Could not access param %s", str);
        }

        (void)sprintf(str, "CAL_MAG%u_ZOFF", i);
        res = param_get(param_find(str), &_mag_calibration.z_offset);

        if (res != OK) {
            PX4_ERR("Could not access param %s", str);
        }
    }
}


int DfHmc5883Wrapper::_publish(struct mag_sensor_data &data)
{
    /* Check if calibration values are still up-to-date. */
    bool updated;
    orb_check(_param_update_sub, &updated);

    if (updated) {
        parameter_update_s parameter_update;
        orb_copy(ORB_ID(parameter_update), _param_update_sub, &parameter_update);

        _update_mag_calibration();
    }

    /* Publish mag first. */
    perf_begin(_mag_sample_perf);

    mag_report mag_report = {};
    mag_report.timestamp = hrt_absolute_time();
    mag_report.is_external = true;

    /* The standard external mag by 3DR has x pointing to the
     * right, y pointing backwards, and z down, therefore switch x
     * and y and invert y. */
    const float tmp = data.field_x_ga;
    data.field_x_ga = -data.field_y_ga;
    data.field_y_ga = tmp;

    // TODO: remove these (or get the values)
    mag_report.x_raw = 0;
    mag_report.y_raw = 0;
    mag_report.z_raw = 0;

    matrix::Vector3f mag_val(data.field_x_ga,
                 data.field_y_ga,
                 data.field_z_ga);

    // apply sensor rotation on the accel measurement
    mag_val = _rotation_matrix * mag_val;

    // Apply calibration after rotation.
    mag_report.x = (mag_val(0) - _mag_calibration.x_offset) * _mag_calibration.x_scale;
    mag_report.y = (mag_val(1) - _mag_calibration.y_offset) * _mag_calibration.y_scale;
    mag_report.z = (mag_val(2) - _mag_calibration.z_offset) * _mag_calibration.z_scale;

    // TODO: get these right
    //mag_report.scaling = -1.0f;

    mag_report.device_id = m_id.dev_id;

    // TODO: when is this ever blocked?
    if (!(m_pub_blocked)) {

        if (_mag_topic == nullptr) {
            _mag_topic = orb_advertise_multi(ORB_ID(sensor_mag), &mag_report,
                             &_mag_orb_class_instance, ORB_PRIO_HIGH);

        } else {
            orb_publish(ORB_ID(sensor_mag), _mag_topic, &mag_report);
        }

    }

    perf_end(_mag_sample_perf);

    return 0;
};


namespace df_hmc5883_wrapper
{

DfHmc5883Wrapper *g_dev = nullptr;

int start(enum Rotation rotation, const char *path);
int stop();
int info();
void usage();

int start(enum Rotation rotation, const char *path)
{
    g_dev = new DfHmc5883Wrapper(rotation, path);

    if (g_dev == nullptr) {
        PX4_ERR("failed instantiating DfHmc5883Wrapper object");
        return -1;
    }

    int ret = g_dev->start();

    if (ret != 0) {
        PX4_ERR("DfHmc5883Wrapper start failed");
        return ret;
    }

    // Open the MAG sensor
    DevHandle h;
    DevMgr::getHandle(path, h);

    if (!h.isValid()) {
        DF_LOG_INFO("Error: unable to obtain a valid handle for the receiver at: %s (%d)",
                path, h.getError());
        return -1;
    }

    DevMgr::releaseHandle(h);

    return 0;
}

int stop()
{
    if (g_dev == nullptr) {
        PX4_ERR("driver not running");
        return 1;
    }

    int ret = g_dev->stop();

    if (ret != 0) {
        PX4_ERR("driver could not be stopped");
        return ret;
    }

    delete g_dev;
    g_dev = nullptr;
    return 0;
}

/**
 * Print a little info about the driver.
 */
int
info()
{
    if (g_dev == nullptr) {
        PX4_ERR("driver not running");
        return 1;
    }

    PX4_DEBUG("state @ %p", g_dev);

    return 0;
}

void
usage()
{
    PX4_INFO("Usage: df_hmc5883_wrapper 'start', 'info', 'stop'");
    PX4_INFO("options:");
    PX4_INFO("    -R rotation");
}

} // namespace df_hmc5883_wrapper


int
df_hmc5883_wrapper_main(int argc, char *argv[])
{
    int ch;
    enum Rotation rotation = ROTATION_NONE;
    int ret = 0;
    int myoptind = 1;
    const char *myoptarg = NULL;
    const char *device_path = MAG_DEVICE_PATH;

    /* jump over start/off/etc and look at options first */
    while ((ch = px4_getopt(argc, argv, "R:D:", &myoptind, &myoptarg)) != EOF) {
        switch (ch) {
        case 'R':
            rotation = (enum Rotation)atoi(myoptarg);
            break;

        case 'D':
            device_path = myoptarg;
            break;

        default:
            df_hmc5883_wrapper::usage();
            return 0;
        }
    }

    if (argc <= 1) {
        df_hmc5883_wrapper::usage();
        return 1;
    }

    const char *verb = argv[myoptind];


    if (!strcmp(verb, "start")) {
        ret = df_hmc5883_wrapper::start(rotation, device_path);
    }

    else if (!strcmp(verb, "stop")) {
        ret = df_hmc5883_wrapper::stop();
    }

    else if (!strcmp(verb, "info")) {
        ret = df_hmc5883_wrapper::info();
    }

    else {
        df_hmc5883_wrapper::usage();
        return 1;
    }

    return ret;
}