PX4-Autopilot/src/modules/commander/mag_calibration.cpp

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/**
 * @file mag_calibration.cpp
 *
 * Magnetometer calibration routine
 */

#include "mag_calibration.h"
#include "commander_helper.h"
#include "calibration_routines.h"
#include "calibration_messages.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <poll.h>
#include <math.h>
#include <fcntl.h>
#include <drivers/drv_hrt.h>
#include <uORB/topics/sensor_combined.h>
#include <drivers/drv_mag.h>
#include <mavlink/mavlink_log.h>
#include <systemlib/param/param.h>
#include <systemlib/err.h>

/* oddly, ERROR is not defined for c++ */
#ifdef ERROR
# undef ERROR
#endif
static const int ERROR = -1;

static const char *sensor_name = "mag";

int do_mag_calibration(int mavlink_fd)
{
	mavlink_log_info(mavlink_fd, CAL_STARTED_MSG, sensor_name);
	mavlink_log_info(mavlink_fd, "don't move system");

	/* 45 seconds */
	uint64_t calibration_interval = 45 * 1000 * 1000;

	/* maximum 500 values */
	const unsigned int calibration_maxcount = 240;
	unsigned int calibration_counter;

	struct mag_scale mscale_null = {
		0.0f,
		1.0f,
		0.0f,
		1.0f,
		0.0f,
		1.0f,
	};

	int res = OK;

	/* erase old calibration */
	int fd = open(MAG_DEVICE_PATH, O_RDONLY);
	res = ioctl(fd, MAGIOCSSCALE, (long unsigned int)&mscale_null);

	if (res != OK) {
		mavlink_log_critical(mavlink_fd, CAL_FAILED_RESET_CAL_MSG);
	}

	if (res == OK) {
		/* calibrate range */
		res = ioctl(fd, MAGIOCCALIBRATE, fd);

		if (res != OK) {
			mavlink_log_critical(mavlink_fd, "Skipped scale calibration");
			/* this is non-fatal - mark it accordingly */
			res = OK;
		}
	}

	close(fd);

	float *x = NULL;
	float *y = NULL;
	float *z = NULL;

	if (res == OK) {
		/* allocate memory */
		mavlink_log_info(mavlink_fd, CAL_PROGRESS_MSG, sensor_name, 20);

		x = reinterpret_cast<float *>(malloc(sizeof(float) * calibration_maxcount));
		y = reinterpret_cast<float *>(malloc(sizeof(float) * calibration_maxcount));
		z = reinterpret_cast<float *>(malloc(sizeof(float) * calibration_maxcount));

		if (x == NULL || y == NULL || z == NULL) {
			mavlink_log_critical(mavlink_fd, "ERROR: out of memory");

			/* clean up */
			if (x != NULL) {
				free(x);
			}

			if (y != NULL) {
				free(y);
			}

			if (z != NULL) {
				free(z);
			}

			res = ERROR;
			return res;
		}

	} else {
		/* exit */
		return ERROR;
	}

	if (res == OK) {
		int sub_mag = orb_subscribe(ORB_ID(sensor_mag0));
		struct mag_report mag;

		/* limit update rate to get equally spaced measurements over time (in ms) */
		orb_set_interval(sub_mag, (calibration_interval / 1000) / calibration_maxcount);

		/* calibrate offsets */
		uint64_t calibration_deadline = hrt_absolute_time() + calibration_interval;
		unsigned poll_errcount = 0;

		mavlink_log_info(mavlink_fd, "Turn on all sides: front/back,left/right,up/down");

		calibration_counter = 0;

		while (hrt_absolute_time() < calibration_deadline &&
		       calibration_counter < calibration_maxcount) {

			/* wait blocking for new data */
			struct pollfd fds[1];
			fds[0].fd = sub_mag;
			fds[0].events = POLLIN;

			int poll_ret = poll(fds, 1, 1000);

			if (poll_ret > 0) {
				orb_copy(ORB_ID(sensor_mag0), sub_mag, &mag);

				x[calibration_counter] = mag.x;
				y[calibration_counter] = mag.y;
				z[calibration_counter] = mag.z;

				calibration_counter++;

				if (calibration_counter % (calibration_maxcount / 20) == 0) {
					mavlink_log_info(mavlink_fd, CAL_PROGRESS_MSG, sensor_name, 20 + (calibration_counter * 50) / calibration_maxcount);
				}

			} else {
				poll_errcount++;
			}

			if (poll_errcount > 1000) {
				mavlink_log_critical(mavlink_fd, CAL_FAILED_SENSOR_MSG);
				res = ERROR;
				break;
			}
		}

		close(sub_mag);
	}

	float sphere_x;
	float sphere_y;
	float sphere_z;
	float sphere_radius;

	if (res == OK) {

		/* sphere fit */
		mavlink_log_info(mavlink_fd, CAL_PROGRESS_MSG, sensor_name, 70);
		sphere_fit_least_squares(x, y, z, calibration_counter, 100, 0.0f, &sphere_x, &sphere_y, &sphere_z, &sphere_radius);
		mavlink_log_info(mavlink_fd, CAL_PROGRESS_MSG, sensor_name, 80);

		if (!isfinite(sphere_x) || !isfinite(sphere_y) || !isfinite(sphere_z)) {
			mavlink_log_critical(mavlink_fd, "ERROR: NaN in sphere fit");
			res = ERROR;
		}
	}

	if (x != NULL) {
		free(x);
	}

	if (y != NULL) {
		free(y);
	}

	if (z != NULL) {
		free(z);
	}

	if (res == OK) {
		/* apply calibration and set parameters */
		struct mag_scale mscale;

		fd = open(MAG_DEVICE_PATH, 0);
		res = ioctl(fd, MAGIOCGSCALE, (long unsigned int)&mscale);

		if (res != OK) {
			mavlink_log_critical(mavlink_fd, "ERROR: failed to get current calibration");
		}

		if (res == OK) {
			mscale.x_offset = sphere_x;
			mscale.y_offset = sphere_y;
			mscale.z_offset = sphere_z;

			res = ioctl(fd, MAGIOCSSCALE, (long unsigned int)&mscale);

			if (res != OK) {
				mavlink_log_critical(mavlink_fd, CAL_FAILED_APPLY_CAL_MSG);
			}
		}

		close(fd);

		if (res == OK) {
			/* set parameters */
			if (param_set(param_find("SENS_MAG_XOFF"), &(mscale.x_offset))) {
				res = ERROR;
			}

			if (param_set(param_find("SENS_MAG_YOFF"), &(mscale.y_offset))) {
				res = ERROR;
			}

			if (param_set(param_find("SENS_MAG_ZOFF"), &(mscale.z_offset))) {
				res = ERROR;
			}

			if (param_set(param_find("SENS_MAG_XSCALE"), &(mscale.x_scale))) {
				res = ERROR;
			}

			if (param_set(param_find("SENS_MAG_YSCALE"), &(mscale.y_scale))) {
				res = ERROR;
			}

			if (param_set(param_find("SENS_MAG_ZSCALE"), &(mscale.z_scale))) {
				res = ERROR;
			}

			if (res != OK) {
				mavlink_log_critical(mavlink_fd, CAL_FAILED_SET_PARAMS_MSG);
			}

			mavlink_log_info(mavlink_fd, CAL_PROGRESS_MSG, sensor_name, 90);
		}

		if (res == OK) {
			/* auto-save to EEPROM */
			res = param_save_default();

			if (res != OK) {
				mavlink_log_critical(mavlink_fd, CAL_FAILED_SAVE_PARAMS_MSG);
			}
		}

		mavlink_log_info(mavlink_fd, "mag off: x:%.2f y:%.2f z:%.2f Ga", (double)mscale.x_offset,
				 (double)mscale.y_offset, (double)mscale.z_offset);
		mavlink_log_info(mavlink_fd, "mag scale: x:%.2f y:%.2f z:%.2f", (double)mscale.x_scale,
				 (double)mscale.y_scale, (double)mscale.z_scale);

		if (res == OK) {
			mavlink_log_info(mavlink_fd, CAL_DONE_MSG, sensor_name);

		} else {
			mavlink_log_info(mavlink_fd, CAL_FAILED_MSG, sensor_name);
		}
	}

	return res;
}