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

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/**
 * @file esc_calibration.cpp
 *
 * Definition of esc calibration
 *
 * @author Roman Bapst <roman@px4.io>
 */

#include "esc_calibration.h"
#include "calibration_messages.h"
#include "calibration_routines.h"

#include <drivers/drv_hrt.h>
#include <drivers/drv_pwm_output.h>
#include <px4_platform_common/defines.h>
#include <px4_platform_common/posix.h>
#include <px4_platform_common/time.h>
#include <systemlib/mavlink_log.h>
#include <uORB/Subscription.hpp>
#include <uORB/topics/battery_status.h>

using namespace time_literals;

int do_esc_calibration(orb_advert_t *mavlink_log_pub, struct actuator_armed_s *armed)
{
	int	return_code = PX4_OK;
	int	fd = -1;
	bool	batt_connected = true;	// for safety reasons assume battery is connected, will be cleared below if not the case
	hrt_abstime timeout_start = 0;

	calibration_log_info(mavlink_log_pub, CAL_QGC_STARTED_MSG, "esc");

	uORB::SubscriptionData<battery_status_s> batt_sub{ORB_ID(battery_status)};
	const battery_status_s &battery = batt_sub.get();

	batt_sub.update();

	if (battery.timestamp == 0) {
		calibration_log_critical(mavlink_log_pub, CAL_QGC_FAILED_MSG, "battery unavailable");
		return_code = PX4_ERROR;
		goto Out;
	}

	// Make sure battery is disconnected
	// battery is not connected if the connected flag is not set and we have a recent battery measurement
	batt_sub.update();

	if (!battery.connected && (hrt_elapsed_time(&battery.timestamp) < 500_ms)) {
		batt_connected = false;
	}

	if (batt_connected) {
		calibration_log_critical(mavlink_log_pub, CAL_QGC_FAILED_MSG, "Disconnect battery and try again");
		return_code = PX4_ERROR;
		goto Out;
	}

	armed->in_esc_calibration_mode = true;

	fd = px4_open(PWM_OUTPUT0_DEVICE_PATH, 0);

	if (fd < 0) {
		calibration_log_critical(mavlink_log_pub, CAL_QGC_FAILED_MSG, "Can't open PWM device");
		return_code = PX4_ERROR;
		goto Out;
	}

	/* tell IO/FMU that its ok to disable its safety with the switch */
	if (px4_ioctl(fd, PWM_SERVO_SET_ARM_OK, 0) != PX4_OK) {
		calibration_log_critical(mavlink_log_pub, CAL_QGC_FAILED_MSG, "Unable to disable safety switch");
		return_code = PX4_ERROR;
		goto Out;
	}

	/* tell IO/FMU that the system is armed (it will output values if safety is off) */
	if (px4_ioctl(fd, PWM_SERVO_ARM, 0) != PX4_OK) {
		calibration_log_critical(mavlink_log_pub, CAL_QGC_FAILED_MSG, "Unable to arm system");
		return_code = PX4_ERROR;
		goto Out;
	}

	/* tell IO to switch off safety without using the safety switch */
	if (px4_ioctl(fd, PWM_SERVO_SET_FORCE_SAFETY_OFF, 0) != PX4_OK) {
		calibration_log_critical(mavlink_log_pub, CAL_QGC_FAILED_MSG, "Unable to force safety off");
		return_code = PX4_ERROR;
		goto Out;
	}

	calibration_log_info(mavlink_log_pub, "[cal] Connect battery now");

	timeout_start = hrt_absolute_time();

	while (true) {
		// We are either waiting for the user to connect the battery. Or we are waiting to let the PWM
		// sit high.
		static constexpr hrt_abstime battery_connect_wait_timeout{20_s};
		static constexpr hrt_abstime pwm_high_timeout{3_s};
		hrt_abstime timeout_wait = batt_connected ? pwm_high_timeout : battery_connect_wait_timeout;

		if (hrt_elapsed_time(&timeout_start) > timeout_wait) {
			if (!batt_connected) {
				calibration_log_critical(mavlink_log_pub, CAL_QGC_FAILED_MSG, "Timeout waiting for battery");
				return_code = PX4_ERROR;
				goto Out;
			}

			// PWM was high long enough
			break;
		}

		if (!batt_connected) {
			if (batt_sub.update()) {
				if (battery.connected) {
					// Battery is connected, signal to user and start waiting again
					batt_connected = true;
					timeout_start = hrt_absolute_time();
					calibration_log_info(mavlink_log_pub, "[cal] Battery connected");
				}
			}
		}

		px4_usleep(50_ms);
	}

Out:

	if (fd != -1) {
		if (px4_ioctl(fd, PWM_SERVO_SET_FORCE_SAFETY_ON, 0) != PX4_OK) {
			calibration_log_info(mavlink_log_pub, CAL_QGC_FAILED_MSG, "Safety switch still off");
		}

		if (px4_ioctl(fd, PWM_SERVO_DISARM, 0) != PX4_OK) {
			calibration_log_info(mavlink_log_pub, CAL_QGC_FAILED_MSG, "Servos still armed");
		}

		if (px4_ioctl(fd, PWM_SERVO_CLEAR_ARM_OK, 0) != PX4_OK) {
			calibration_log_info(mavlink_log_pub, CAL_QGC_FAILED_MSG, "Safety switch still deactivated");
		}

		px4_close(fd);
	}

	armed->in_esc_calibration_mode = false;

	if (return_code == PX4_OK) {
		calibration_log_info(mavlink_log_pub, CAL_QGC_DONE_MSG, "esc");
	}

	return return_code;
}