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/**
 * @file gyro_calibration.cpp
 * Gyroscope calibration routine
 */

#include "gyro_calibration.h"
#include "commander_helper.h"

#include <stdio.h>
#include <fcntl.h>
#include <poll.h>
#include <math.h>
#include <drivers/drv_hrt.h>
#include <uORB/topics/sensor_combined.h>
#include <drivers/drv_gyro.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;

int do_gyro_calibration(int mavlink_fd)
{
	mavlink_log_info(mavlink_fd, "Gyro calibration starting, do not move unit.");

	const int calibration_count = 5000;

	int sub_sensor_combined = orb_subscribe(ORB_ID(sensor_combined));
	struct sensor_combined_s raw;

	int calibration_counter = 0;
	float gyro_offset[3] = {0.0f, 0.0f, 0.0f};

	/* set offsets to zero */
	int fd = open(GYRO_DEVICE_PATH, 0);
	struct gyro_scale gscale_null = {
		0.0f,
		1.0f,
		0.0f,
		1.0f,
		0.0f,
		1.0f,
	};

	if (OK != ioctl(fd, GYROIOCSSCALE, (long unsigned int)&gscale_null))
		warn("WARNING: failed to set scale / offsets for gyro");

	close(fd);

	unsigned poll_errcount = 0;

	while (calibration_counter < calibration_count) {

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

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

		if (poll_ret > 0) {
			orb_copy(ORB_ID(sensor_combined), sub_sensor_combined, &raw);
			gyro_offset[0] += raw.gyro_rad_s[0];
			gyro_offset[1] += raw.gyro_rad_s[1];
			gyro_offset[2] += raw.gyro_rad_s[2];
			calibration_counter++;

		} else {
			poll_errcount++;
		}

		if (poll_errcount > 1000) {
			mavlink_log_info(mavlink_fd, "ERROR: Failed reading gyro sensor");
			return ERROR;
		}
	}

	gyro_offset[0] = gyro_offset[0] / calibration_count;
	gyro_offset[1] = gyro_offset[1] / calibration_count;
	gyro_offset[2] = gyro_offset[2] / calibration_count;


	if (isfinite(gyro_offset[0]) && isfinite(gyro_offset[1]) && isfinite(gyro_offset[2])) {

		if (param_set(param_find("SENS_GYRO_XOFF"), &(gyro_offset[0]))
			|| param_set(param_find("SENS_GYRO_YOFF"), &(gyro_offset[1]))
			|| param_set(param_find("SENS_GYRO_ZOFF"), &(gyro_offset[2]))) {
			mavlink_log_critical(mavlink_fd, "Setting gyro offsets failed!");
		}

		/* set offsets to actual value */
		fd = open(GYRO_DEVICE_PATH, 0);
		struct gyro_scale gscale = {
			gyro_offset[0],
			1.0f,
			gyro_offset[1],
			1.0f,
			gyro_offset[2],
			1.0f,
		};

		if (OK != ioctl(fd, GYROIOCSSCALE, (long unsigned int)&gscale))
			warn("WARNING: failed to set scale / offsets for gyro");

		close(fd);

		/* auto-save to EEPROM */
		int save_ret = param_save_default();

		if (save_ret != 0) {
			warnx("WARNING: auto-save of params to storage failed");
			mavlink_log_critical(mavlink_fd, "gyro store failed");
			return ERROR;
		}

		mavlink_log_info(mavlink_fd, "gyro calibration done");

		tune_neutral();
		/* third beep by cal end routine */

	} else {
		mavlink_log_info(mavlink_fd, "offset cal FAILED (NaN)");
		return ERROR;
	}


	/*** --- SCALING --- ***/

	mavlink_log_info(mavlink_fd, "offset calibration finished. Rotate for scale 30x");
	mavlink_log_info(mavlink_fd, "or do not rotate and wait for 5 seconds to skip.");
	warnx("offset calibration finished. Rotate for scale 30x, or do not rotate and wait for 5 seconds to skip.");

	unsigned rotations_count = 30;
	float gyro_integral = 0.0f;
	float baseline_integral = 0.0f;

	// XXX change to mag topic
	orb_copy(ORB_ID(sensor_combined), sub_sensor_combined, &raw);

	float mag_last = -atan2f(raw.magnetometer_ga[1],raw.magnetometer_ga[0]);
	if (mag_last > M_PI_F) mag_last -= 2*M_PI_F;
	if (mag_last < -M_PI_F) mag_last += 2*M_PI_F;


	uint64_t last_time = hrt_absolute_time();
	uint64_t start_time = hrt_absolute_time();

	while ((int)fabsf(baseline_integral / (2.0f * M_PI_F)) < rotations_count) {

		/* abort this loop if not rotated more than 180 degrees within 5 seconds */
		if ((fabsf(baseline_integral / (2.0f * M_PI_F)) < 0.6f)
			&& (hrt_absolute_time() - start_time > 5 * 1e6)) {
			mavlink_log_info(mavlink_fd, "gyro scale calibration skipped");
			mavlink_log_info(mavlink_fd, "gyro calibration done");
			return OK;
		}

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

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

		if (poll_ret) {

			float dt_ms = (hrt_absolute_time() - last_time) / 1e3f;
			last_time = hrt_absolute_time();

			orb_copy(ORB_ID(sensor_combined), sub_sensor_combined, &raw);

			// XXX this is just a proof of concept and needs world / body
			// transformation and more

			//math::Vector2f magNav(raw.magnetometer_ga);

			// calculate error between estimate and measurement
			// apply declination correction for true heading as well.
			//float mag = -atan2f(magNav(1),magNav(0));
			float mag = -atan2f(raw.magnetometer_ga[1],raw.magnetometer_ga[0]);
			if (mag > M_PI_F) mag -= 2*M_PI_F;
			if (mag < -M_PI_F) mag += 2*M_PI_F;

			float diff = mag - mag_last;

			if (diff > M_PI_F) diff -= 2*M_PI_F;
			if (diff < -M_PI_F) diff += 2*M_PI_F;

			baseline_integral += diff;
			mag_last = mag;
			// Jump through some timing scale hoops to avoid
			// operating near the 1e6/1e8 max sane resolution of float.
			gyro_integral += (raw.gyro_rad_s[2] * dt_ms) / 1e3f;

//			warnx("dbg: b: %6.4f, g: %6.4f", (double)baseline_integral, (double)gyro_integral);

		// } else if (poll_ret == 0) {
		// 	/* any poll failure for 1s is a reason to abort */
		// 	mavlink_log_info(mavlink_fd, "gyro calibration aborted, retry");
		// 	return;
		}
	}

	float gyro_scale = baseline_integral / gyro_integral;
	float gyro_scales[] = { gyro_scale, gyro_scale, gyro_scale };
	warnx("gyro scale: yaw (z): %6.4f", (double)gyro_scale);
	mavlink_log_info(mavlink_fd, "gyro scale: yaw (z): %6.4f", (double)gyro_scale);


	if (isfinite(gyro_scales[0]) && isfinite(gyro_scales[1]) && isfinite(gyro_scales[2])) {

		if (param_set(param_find("SENS_GYRO_XSCALE"), &(gyro_scales[0]))
			|| param_set(param_find("SENS_GYRO_YSCALE"), &(gyro_scales[1]))
			|| param_set(param_find("SENS_GYRO_ZSCALE"), &(gyro_scales[2]))) {
			mavlink_log_critical(mavlink_fd, "Setting gyro scale failed!");
		}

		/* set offsets to actual value */
		fd = open(GYRO_DEVICE_PATH, 0);
		struct gyro_scale gscale = {
			gyro_offset[0],
			gyro_scales[0],
			gyro_offset[1],
			gyro_scales[1],
			gyro_offset[2],
			gyro_scales[2],
		};

		if (OK != ioctl(fd, GYROIOCSSCALE, (long unsigned int)&gscale))
			warn("WARNING: failed to set scale / offsets for gyro");

		close(fd);

		/* auto-save to EEPROM */
		int save_ret = param_save_default();

		if (save_ret != 0) {
			warn("WARNING: auto-save of params to storage failed");
		}

		// char buf[50];
		// sprintf(buf, "cal: x:%8.4f y:%8.4f z:%8.4f", (double)gyro_offset[0], (double)gyro_offset[1], (double)gyro_offset[2]);
		// mavlink_log_info(mavlink_fd, buf);
		mavlink_log_info(mavlink_fd, "gyro calibration done");

		/* third beep by cal end routine */
		return OK;
	} else {
		mavlink_log_info(mavlink_fd, "gyro calibration FAILED (NaN)");
		return ERROR;
	}
}