moved commander to C++, preparation for better gyro scale calibration respecting the current attitude for more accurate results

1 files changed, 1720 insertions, 0 deletions

diff --git a/src/modules/commander/commander.cpp b/src/modules/commander/commander.cpp
new file mode 100644
index 000000000..253b6295f
--- /dev/null
+++ b/src/modules/commander/commander.cpp
@@ -0,0 +1,1720 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2013 PX4 Development Team. All rights reserved.
+ *   Author: Petri Tanskanen <petri.tanskanen@inf.ethz.ch>
+ *           Lorenz Meier <lm@inf.ethz.ch>
+ *           Thomas Gubler <thomasgubler@student.ethz.ch>
+ *           Julian Oes <joes@student.ethz.ch>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file commander.cpp
+ * Main system state machine implementation.
+ *
+ */
+
+#include <nuttx/config.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <debug.h>
+#include <sys/prctl.h>
+#include <string.h>
+#include <math.h>
+#include <poll.h>
+
+#include <uORB/uORB.h>
+#include <uORB/topics/sensor_combined.h>
+#include <uORB/topics/battery_status.h>
+#include <uORB/topics/manual_control_setpoint.h>
+#include <uORB/topics/offboard_control_setpoint.h>
+#include <uORB/topics/home_position.h>
+#include <uORB/topics/vehicle_global_position.h>
+#include <uORB/topics/vehicle_local_position.h>
+#include <uORB/topics/vehicle_gps_position.h>
+#include <uORB/topics/vehicle_command.h>
+#include <uORB/topics/vehicle_control_mode.h>
+#include <uORB/topics/subsystem_info.h>
+#include <uORB/topics/actuator_controls.h>
+#include <uORB/topics/actuator_armed.h>
+#include <uORB/topics/parameter_update.h>
+#include <uORB/topics/differential_pressure.h>
+#include <uORB/topics/safety.h>
+#include <mavlink/mavlink_log.h>
+
+#include <drivers/drv_led.h>
+#include <drivers/drv_hrt.h>
+#include <drivers/drv_tone_alarm.h>
+
+#include <mavlink/mavlink_log.h>
+#include <systemlib/param/param.h>
+#include <systemlib/systemlib.h>
+#include <systemlib/err.h>
+#include <systemlib/cpuload.h>
+
+#include "commander_helper.h"
+#include "state_machine_helper.h"
+#include "calibration_routines.h"
+#include "accelerometer_calibration.h"
+#include "gyro_calibration.h"
+#include "mag_calibration.h"
+#include "baro_calibration.h"
+#include "rc_calibration.h"
+#include "airspeed_calibration.h"
+
+/* oddly, ERROR is not defined for c++ */
+#ifdef ERROR
+# undef ERROR
+#endif
+static const int ERROR = -1;
+
+extern struct system_load_s system_load;
+
+#define LOW_VOLTAGE_BATTERY_HYSTERESIS_TIME_MS 1000.0f
+#define CRITICAL_VOLTAGE_BATTERY_HYSTERESIS_TIME_MS 100.0f
+
+/* Decouple update interval and hysteris counters, all depends on intervals */
+#define COMMANDER_MONITORING_INTERVAL 50000
+#define COMMANDER_MONITORING_LOOPSPERMSEC (1/(COMMANDER_MONITORING_INTERVAL/1000.0f))
+#define LOW_VOLTAGE_BATTERY_COUNTER_LIMIT (LOW_VOLTAGE_BATTERY_HYSTERESIS_TIME_MS*COMMANDER_MONITORING_LOOPSPERMSEC)
+#define CRITICAL_VOLTAGE_BATTERY_COUNTER_LIMIT (CRITICAL_VOLTAGE_BATTERY_HYSTERESIS_TIME_MS*COMMANDER_MONITORING_LOOPSPERMSEC)
+
+#define STICK_ON_OFF_LIMIT 0.75f
+#define STICK_THRUST_RANGE 1.0f
+#define STICK_ON_OFF_HYSTERESIS_TIME_MS 1000
+#define STICK_ON_OFF_COUNTER_LIMIT (STICK_ON_OFF_HYSTERESIS_TIME_MS*COMMANDER_MONITORING_LOOPSPERMSEC)
+
+#define GPS_FIX_TYPE_2D 2
+#define GPS_FIX_TYPE_3D 3
+#define GPS_QUALITY_GOOD_HYSTERIS_TIME_MS 5000
+#define GPS_QUALITY_GOOD_COUNTER_LIMIT (GPS_QUALITY_GOOD_HYSTERIS_TIME_MS*COMMANDER_MONITORING_LOOPSPERMSEC)
+
+#define LOCAL_POSITION_TIMEOUT 1000000 /**< consider the local position estimate invalid after 1s */
+
+/* Mavlink file descriptors */
+static int mavlink_fd;
+
+/* flags */
+static bool commander_initialized = false;
+static bool thread_should_exit = false;		/**< daemon exit flag */
+static bool thread_running = false;		/**< daemon status flag */
+static int daemon_task;				/**< Handle of daemon task / thread */
+
+/* timout until lowlevel failsafe */
+static unsigned int failsafe_lowlevel_timeout_ms;
+
+/* tasks waiting for low prio thread */
+enum {
+	LOW_PRIO_TASK_NONE = 0,
+	LOW_PRIO_TASK_PARAM_SAVE,
+	LOW_PRIO_TASK_PARAM_LOAD,
+	LOW_PRIO_TASK_GYRO_CALIBRATION,
+	LOW_PRIO_TASK_MAG_CALIBRATION,
+	LOW_PRIO_TASK_ALTITUDE_CALIBRATION,
+	LOW_PRIO_TASK_RC_CALIBRATION,
+	LOW_PRIO_TASK_ACCEL_CALIBRATION,
+	LOW_PRIO_TASK_AIRSPEED_CALIBRATION
+} low_prio_task;
+
+
+/**
+ * The daemon app only briefly exists to start
+ * the background job. The stack size assigned in the
+ * Makefile does only apply to this management task.
+ *
+ * The actual stack size should be set in the call
+ * to task_create().
+ *
+ * @ingroup apps
+ */
+extern "C" __EXPORT int commander_main(int argc, char *argv[]);
+
+/**
+ * Print the correct usage.
+ */
+void usage(const char *reason);
+
+/**
+ * React to commands that are sent e.g. from the mavlink module.
+ */
+void handle_command(int status_pub, struct vehicle_status_s *current_status, int control_mode_pub, struct vehicle_control_mode_s *current_control_mode, struct vehicle_command_s *cmd, int armed_pub, struct actuator_armed_s *armed);
+
+/**
+ * Mainloop of commander.
+ */
+int commander_thread_main(int argc, char *argv[]);
+
+/**
+ * Loop that runs at a lower rate and priority for calibration and parameter tasks.
+ */
+void *commander_low_prio_loop(void *arg);
+
+
+int commander_main(int argc, char *argv[])
+{
+	if (argc < 1)
+		usage("missing command");
+
+	if (!strcmp(argv[1], "start")) {
+
+		if (thread_running) {
+			warnx("commander already running\n");
+			/* this is not an error */
+			exit(0);
+		}
+
+		thread_should_exit = false;
+		daemon_task = task_spawn_cmd("commander",
+					 SCHED_DEFAULT,
+					 SCHED_PRIORITY_MAX - 40,
+					 3000,
+					 commander_thread_main,
+					 (argv) ? (const char **)&argv[2] : (const char **)NULL);
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "stop")) {
+		thread_should_exit = true;
+		exit(0);
+	}
+
+	if (!strcmp(argv[1], "status")) {
+		if (thread_running) {
+			warnx("\tcommander is running\n");
+
+		} else {
+			warnx("\tcommander not started\n");
+		}
+
+		exit(0);
+	}
+
+	usage("unrecognized command");
+	exit(1);
+}
+
+void usage(const char *reason)
+{
+	if (reason)
+		fprintf(stderr, "%s\n", reason);
+
+	fprintf(stderr, "usage: daemon {start|stop|status} [-p <additional params>]\n\n");
+	exit(1);
+}
+
+void handle_command(int status_pub, struct vehicle_status_s *current_status, int control_mode_pub, struct vehicle_control_mode_s *current_control_mode, struct vehicle_command_s *cmd, int armed_pub, struct actuator_armed_s *armed)
+{
+	/* result of the command */
+	uint8_t result = VEHICLE_CMD_RESULT_UNSUPPORTED;
+
+	/* request to set different system mode */
+	switch (cmd->command) {
+		case VEHICLE_CMD_DO_SET_MODE:
+
+			/* request to activate HIL */
+			if ((int)cmd->param1 & VEHICLE_MODE_FLAG_HIL_ENABLED) {
+
+				if (OK == hil_state_transition(HIL_STATE_ON, status_pub, current_status, control_mode_pub, current_control_mode, mavlink_fd)) {
+					result = VEHICLE_CMD_RESULT_ACCEPTED;
+				} else {
+					result = VEHICLE_CMD_RESULT_DENIED;
+				}
+			}
+
+			if ((int)cmd->param1 & VEHICLE_MODE_FLAG_SAFETY_ARMED) {
+				if (OK == arming_state_transition(status_pub, current_status, ARMING_STATE_ARMED, armed_pub, armed, mavlink_fd)) {
+					result = VEHICLE_CMD_RESULT_ACCEPTED;
+				} else {
+					result = VEHICLE_CMD_RESULT_DENIED;
+				}
+			} else {
+				if (OK == arming_state_transition(status_pub, current_status, ARMING_STATE_STANDBY, armed_pub, armed, mavlink_fd)) {
+					result = VEHICLE_CMD_RESULT_ACCEPTED;
+				} else {
+					result = VEHICLE_CMD_RESULT_DENIED;
+				}
+			}
+
+			break;
+
+		case VEHICLE_CMD_COMPONENT_ARM_DISARM:
+
+			/* request to arm */
+			if ((int)cmd->param1 == 1) {
+				if (OK == arming_state_transition(status_pub, current_status, ARMING_STATE_ARMED, armed_pub, armed, mavlink_fd)) {
+					result = VEHICLE_CMD_RESULT_ACCEPTED;
+				} else {
+					result = VEHICLE_CMD_RESULT_DENIED;
+				}
+			/* request to disarm */
+			} else if ((int)cmd->param1 == 0) {
+				if (OK == arming_state_transition(status_pub, current_status, ARMING_STATE_STANDBY, armed_pub, armed, mavlink_fd)) {
+					result = VEHICLE_CMD_RESULT_ACCEPTED;
+				} else {
+					result = VEHICLE_CMD_RESULT_DENIED;
+				}
+			}
+
+			break;
+
+		case VEHICLE_CMD_PREFLIGHT_REBOOT_SHUTDOWN: {
+
+			/* request for an autopilot reboot */
+			if ((int)cmd->param1 == 1) {
+					if (OK == arming_state_transition(status_pub, current_status, ARMING_STATE_REBOOT, armed_pub, armed, mavlink_fd)) {
+						/* reboot is executed later, after positive tune is sent */
+						result = VEHICLE_CMD_RESULT_ACCEPTED;
+						tune_positive();
+						mavlink_log_critical(mavlink_fd, "REBOOTING SYSTEM");
+						usleep(500000);
+						up_systemreset();
+						/* SPECIAL CASE: NEVER RETURNS FROM THIS FUNCTION CALL */
+
+					} else {
+						/* system may return here */
+						result = VEHICLE_CMD_RESULT_DENIED;
+						tune_negative();
+					}
+				}
+			}
+			break;
+
+	//		/* request to land */
+	//		case VEHICLE_CMD_NAV_LAND:
+	//		 {
+	//				//TODO: add check if landing possible
+	//				//TODO: add landing maneuver
+	//
+	//				if (0 == update_state_machine_custom_mode_request(status_pub, current_vehicle_status, SYSTEM_STATE_ARMED)) {
+	//					result = VEHICLE_CMD_RESULT_ACCEPTED;
+	//		}		}
+	//		break;
+	//
+	//		/* request to takeoff */
+	//		case VEHICLE_CMD_NAV_TAKEOFF:
+	//		{
+	//			//TODO: add check if takeoff possible
+	//			//TODO: add takeoff maneuver
+	//
+	//			if (0 == update_state_machine_custom_mode_request(status_pub, current_vehicle_status, SYSTEM_STATE_AUTO)) {
+	//				result = VEHICLE_CMD_RESULT_ACCEPTED;
+	//			}
+	//		}
+	//		break;
+	//
+			/* preflight calibration */
+		case VEHICLE_CMD_PREFLIGHT_CALIBRATION:
+
+			/* gyro calibration */
+			if ((int)(cmd->param1) == 1) {
+
+				/* check if no other task is scheduled */
+				if(low_prio_task == LOW_PRIO_TASK_NONE) {
+
+					/* try to go to INIT/PREFLIGHT arming state */
+					if (OK == arming_state_transition(status_pub, current_status, ARMING_STATE_INIT, armed_pub, armed, mavlink_fd)) {
+						result = VEHICLE_CMD_RESULT_ACCEPTED;
+						/* now set the task for the low prio thread */
+						low_prio_task = LOW_PRIO_TASK_GYRO_CALIBRATION;
+					} else {
+						result = VEHICLE_CMD_RESULT_DENIED;
+					}
+				} else {
+					result = VEHICLE_CMD_RESULT_TEMPORARILY_REJECTED;
+				}
+			}
+
+			/* magnetometer calibration */
+			if ((int)(cmd->param2) == 1) {
+
+				/* check if no other task is scheduled */
+				if(low_prio_task == LOW_PRIO_TASK_NONE) {
+
+					/* try to go to INIT/PREFLIGHT arming state */
+					if (OK == arming_state_transition(status_pub, current_status, ARMING_STATE_INIT, armed_pub, armed, mavlink_fd)) {
+						result = VEHICLE_CMD_RESULT_ACCEPTED;
+						/* now set the task for the low prio thread */
+						low_prio_task = LOW_PRIO_TASK_MAG_CALIBRATION;
+					} else {
+						result = VEHICLE_CMD_RESULT_DENIED;
+					}
+				} else {
+					result = VEHICLE_CMD_RESULT_TEMPORARILY_REJECTED;
+				}
+			}
+
+
+			// /* zero-altitude pressure calibration */
+			// if ((int)(cmd->param3) == 1) {
+
+			// 	/* check if no other task is scheduled */
+			// 	if(low_prio_task == LOW_PRIO_TASK_NONE) {
+
+			// 		/* try to go to INIT/PREFLIGHT arming state */
+			// 		if (OK == arming_state_transition(status_pub, current_vehicle_status, ARMING_STATE_INIT, armed_pub, armed, mavlink_fd)) {
+			// 			result = VEHICLE_CMD_RESULT_ACCEPTED;
+			// 			/* now set the task for the low prio thread */
+			// 			low_prio_task = LOW_PRIO_TASK_ALTITUDE_CALIBRATION;
+			// 		} else {
+			// 			result = VEHICLE_CMD_RESULT_DENIED;
+			// 		}
+			// 	} else {
+			// 		result = VEHICLE_CMD_RESULT_TEMPORARILY_REJECTED;
+			// 	}
+			// }
+
+
+
+			// /* trim calibration */
+			// if ((int)(cmd->param4) == 1) {
+
+			// 	/* check if no other task is scheduled */
+			// 	if(low_prio_task == LOW_PRIO_TASK_NONE) {
+
+			// 		/* try to go to INIT/PREFLIGHT arming state */
+			// 		if (OK == arming_state_transition(status_pub, current_vehicle_status, ARMING_STATE_INIT, armed_pub, armed, mavlink_fd)) {
+			// 			result = VEHICLE_CMD_RESULT_ACCEPTED;
+			// 			/* now set the task for the low prio thread */
+			// 			low_prio_task = LOW_PRIO_TASK_RC_CALIBRATION;
+			// 		} else {
+			// 			result = VEHICLE_CMD_RESULT_DENIED;
+			// 		}
+			// 	} else {
+			// 		result = VEHICLE_CMD_RESULT_TEMPORARILY_REJECTED;
+			// 	}
+			// }
+
+
+			/* accel calibration */
+			if ((int)(cmd->param5) == 1) {
+
+				/* check if no other task is scheduled */
+				if(low_prio_task == LOW_PRIO_TASK_NONE) {
+
+					/* try to go to INIT/PREFLIGHT arming state */
+					if (OK == arming_state_transition(status_pub, current_status, ARMING_STATE_INIT, armed_pub, armed, mavlink_fd)) {
+						result = VEHICLE_CMD_RESULT_ACCEPTED;
+						/* now set the task for the low prio thread */
+						low_prio_task = LOW_PRIO_TASK_ACCEL_CALIBRATION;
+					} else {
+						result = VEHICLE_CMD_RESULT_DENIED;
+					}
+				} else {
+					result = VEHICLE_CMD_RESULT_TEMPORARILY_REJECTED;
+				}
+			}
+
+			/* airspeed calibration */
+			if ((int)(cmd->param6) == 1) {
+
+				/* check if no other task is scheduled */
+				if(low_prio_task == LOW_PRIO_TASK_NONE) {
+
+					/* try to go to INIT/PREFLIGHT arming state */
+					if (OK == arming_state_transition(status_pub, current_status, ARMING_STATE_INIT, armed_pub, armed, mavlink_fd)) {
+						result = VEHICLE_CMD_RESULT_ACCEPTED;
+						/* now set the task for the low prio thread */
+						low_prio_task = LOW_PRIO_TASK_AIRSPEED_CALIBRATION;
+					} else {
+						result = VEHICLE_CMD_RESULT_DENIED;
+					}
+				} else {
+					result = VEHICLE_CMD_RESULT_TEMPORARILY_REJECTED;
+				}
+			}
+			break;
+
+		case VEHICLE_CMD_PREFLIGHT_STORAGE:
+
+			if (((int)(cmd->param1)) == 0) {
+
+				/* check if no other task is scheduled */
+				if(low_prio_task == LOW_PRIO_TASK_NONE) {
+					low_prio_task = LOW_PRIO_TASK_PARAM_LOAD;
+					result = VEHICLE_CMD_RESULT_ACCEPTED;
+				} else {
+					result = VEHICLE_CMD_RESULT_TEMPORARILY_REJECTED;
+				}
+
+
+			} else if (((int)(cmd->param1)) == 1) {
+
+				/* check if no other task is scheduled */
+				if(low_prio_task == LOW_PRIO_TASK_NONE) {
+					low_prio_task = LOW_PRIO_TASK_PARAM_SAVE;
+					result = VEHICLE_CMD_RESULT_ACCEPTED;
+				} else {
+					result = VEHICLE_CMD_RESULT_TEMPORARILY_REJECTED;
+				}
+			}
+		break;
+
+	default:
+		mavlink_log_critical(mavlink_fd, "[cmd] refusing unsupported command");
+		result = VEHICLE_CMD_RESULT_UNSUPPORTED;
+		break;
+	}
+
+	/* supported command handling stop */
+	if (result == VEHICLE_CMD_RESULT_FAILED ||
+	    result == VEHICLE_CMD_RESULT_DENIED ||
+	    result == VEHICLE_CMD_RESULT_UNSUPPORTED ||
+	    result == VEHICLE_CMD_RESULT_TEMPORARILY_REJECTED) {
+
+		tune_negative();
+
+	} else if (result == VEHICLE_CMD_RESULT_ACCEPTED) {
+
+		tune_positive();
+	}
+
+	/* send any requested ACKs */
+	if (cmd->confirmation > 0) {
+		/* send acknowledge command */
+		// XXX TODO
+	}
+
+}
+
+int commander_thread_main(int argc, char *argv[])
+{
+	/* not yet initialized */
+	commander_initialized = false;
+	bool home_position_set = false;
+
+	bool battery_tune_played = false;
+	bool arm_tune_played = false;
+
+	/* set parameters */
+	failsafe_lowlevel_timeout_ms = 0;
+	param_get(param_find("SYS_FAILSAVE_LL"), &failsafe_lowlevel_timeout_ms);
+
+	param_t _param_sys_type = param_find("MAV_TYPE");
+	param_t _param_system_id = param_find("MAV_SYS_ID");
+	param_t _param_component_id = param_find("MAV_COMP_ID");
+
+	/* welcome user */
+	warnx("[commander] starting");
+
+	/* pthread for slow low prio thread */
+	pthread_t commander_low_prio_thread;
+
+	/* initialize */
+	if (led_init() != 0) {
+		warnx("ERROR: Failed to initialize leds");
+	}
+
+	if (buzzer_init() != OK) {
+		warnx("ERROR: Failed to initialize buzzer");
+	}
+
+	mavlink_fd = open(MAVLINK_LOG_DEVICE, 0);
+
+	if (mavlink_fd < 0) {
+		warnx("ERROR: Failed to open MAVLink log stream, start mavlink app first.");
+	}
+	
+	/* Main state machine */
+	struct vehicle_status_s current_status;
+	orb_advert_t status_pub;
+	/* make sure we are in preflight state */
+	memset(&current_status, 0, sizeof(current_status));
+
+	/* armed topic */
+	struct actuator_armed_s armed;
+	orb_advert_t armed_pub;
+	/* Initialize armed with all false */
+	memset(&armed, 0, sizeof(armed));
+
+	/* flags for control apps */
+	struct vehicle_control_mode_s control_mode;
+	orb_advert_t control_mode_pub;
+
+	/* Initialize all flags to false */
+	memset(&control_mode, 0, sizeof(control_mode));
+
+	current_status.navigation_state = NAVIGATION_STATE_INIT;
+	current_status.arming_state = ARMING_STATE_INIT;
+	current_status.hil_state = HIL_STATE_OFF;
+
+	/* neither manual nor offboard control commands have been received */
+	current_status.offboard_control_signal_found_once = false;
+	current_status.rc_signal_found_once = false;
+
+	/* mark all signals lost as long as they haven't been found */
+	current_status.rc_signal_lost = true;
+	current_status.offboard_control_signal_lost = true;
+
+	/* allow manual override initially */
+	control_mode.flag_external_manual_override_ok = true;
+
+	/* flag position info as bad, do not allow auto mode */
+	// current_status.flag_vector_flight_mode_ok = false;
+
+	/* set battery warning flag */
+	current_status.battery_warning = VEHICLE_BATTERY_WARNING_NONE;
+	
+	/* set safety device detection flag */
+	/* XXX do we need this? */
+	//current_status.flag_safety_present = false;
+
+	// XXX for now just set sensors as initialized
+	current_status.condition_system_sensors_initialized = true;
+
+	// XXX just disable offboard control for now
+	control_mode.flag_control_offboard_enabled = false;
+
+	/* advertise to ORB */
+	status_pub = orb_advertise(ORB_ID(vehicle_status), &current_status);
+	/* publish current state machine */
+	
+	/* publish the new state */
+	current_status.counter++;
+	current_status.timestamp = hrt_absolute_time();
+	orb_publish(ORB_ID(vehicle_status), status_pub, &current_status);
+
+
+	armed_pub = orb_advertise(ORB_ID(actuator_armed), &armed);
+
+	control_mode_pub = orb_advertise(ORB_ID(vehicle_control_mode), &control_mode);	
+
+	/* home position */
+	orb_advert_t home_pub = -1;
+	struct home_position_s home;
+	memset(&home, 0, sizeof(home));
+
+	if (status_pub < 0) {
+		warnx("ERROR: orb_advertise for topic vehicle_status failed (uorb app running?).\n");
+		warnx("exiting.");
+		exit(ERROR);
+	}
+
+	// XXX needed?
+	mavlink_log_info(mavlink_fd, "system is running");
+
+	pthread_attr_t commander_low_prio_attr;
+	pthread_attr_init(&commander_low_prio_attr);
+	pthread_attr_setstacksize(&commander_low_prio_attr, 2048);
+
+	struct sched_param param;
+	/* low priority */
+	param.sched_priority = SCHED_PRIORITY_DEFAULT - 50;
+	(void)pthread_attr_setschedparam(&commander_low_prio_attr, &param);
+	pthread_create(&commander_low_prio_thread, &commander_low_prio_attr, commander_low_prio_loop, NULL);
+
+	/* Start monitoring loop */
+	unsigned counter = 0;
+	unsigned low_voltage_counter = 0;
+	unsigned critical_voltage_counter = 0;
+	unsigned stick_off_counter = 0;
+	unsigned stick_on_counter = 0;
+
+	/* To remember when last notification was sent */
+	uint64_t last_print_time = 0;
+
+	float voltage_previous = 0.0f;
+
+	bool low_battery_voltage_actions_done;
+	bool critical_battery_voltage_actions_done;
+
+	uint64_t last_idle_time = 0;
+
+	uint64_t start_time = 0;
+
+	bool state_changed = true;
+	bool param_init_forced = true;
+
+	bool new_data = false;
+
+	/* Subscribe to safety topic */
+	int safety_sub = orb_subscribe(ORB_ID(safety));
+	struct safety_s safety;
+	memset(&safety, 0, sizeof(safety));
+
+	/* Subscribe to manual control data */
+	int sp_man_sub = orb_subscribe(ORB_ID(manual_control_setpoint));
+	struct manual_control_setpoint_s sp_man;
+	memset(&sp_man, 0, sizeof(sp_man));
+
+	/* Subscribe to offboard control data */
+	int sp_offboard_sub = orb_subscribe(ORB_ID(offboard_control_setpoint));
+	struct offboard_control_setpoint_s sp_offboard;
+	memset(&sp_offboard, 0, sizeof(sp_offboard));
+
+	/* Subscribe to global position */
+	int global_position_sub = orb_subscribe(ORB_ID(vehicle_global_position));
+	struct vehicle_global_position_s global_position;
+	memset(&global_position, 0, sizeof(global_position));
+	uint64_t last_global_position_time = 0;
+
+	/* Subscribe to local position data */
+	int local_position_sub = orb_subscribe(ORB_ID(vehicle_local_position));
+	struct vehicle_local_position_s local_position;
+	memset(&local_position, 0, sizeof(local_position));
+	uint64_t last_local_position_time = 0;
+
+	/* 
+	 * The home position is set based on GPS only, to prevent a dependency between
+	 * position estimator and commander. RAW GPS is more than good enough for a
+	 * non-flying vehicle.
+	 */
+
+	/* Subscribe to GPS topic */
+	int gps_sub = orb_subscribe(ORB_ID(vehicle_gps_position));
+	struct vehicle_gps_position_s gps_position;
+	memset(&gps_position, 0, sizeof(gps_position));
+
+	/* Subscribe to sensor topic */
+	int sensor_sub = orb_subscribe(ORB_ID(sensor_combined));
+	struct sensor_combined_s sensors;
+	memset(&sensors, 0, sizeof(sensors));
+
+	/* Subscribe to differential pressure topic */
+	int diff_pres_sub = orb_subscribe(ORB_ID(differential_pressure));
+	struct differential_pressure_s diff_pres;
+	memset(&diff_pres, 0, sizeof(diff_pres));
+	uint64_t last_diff_pres_time = 0;
+
+	/* Subscribe to command topic */
+	int cmd_sub = orb_subscribe(ORB_ID(vehicle_command));
+	struct vehicle_command_s cmd;
+	memset(&cmd, 0, sizeof(cmd));
+
+	/* Subscribe to parameters changed topic */
+	int param_changed_sub = orb_subscribe(ORB_ID(parameter_update));
+	struct parameter_update_s param_changed;
+	memset(&param_changed, 0, sizeof(param_changed));
+
+	/* Subscribe to battery topic */
+	int battery_sub = orb_subscribe(ORB_ID(battery_status));
+	struct battery_status_s battery;
+	memset(&battery, 0, sizeof(battery));
+	battery.voltage_v = 0.0f;
+
+	/* Subscribe to subsystem info topic */
+	int subsys_sub = orb_subscribe(ORB_ID(subsystem_info));
+	struct subsystem_info_s info;
+	memset(&info, 0, sizeof(info));
+
+	/* now initialized */
+	commander_initialized = true;
+	thread_running = true;
+
+	start_time = hrt_absolute_time();
+
+	while (!thread_should_exit) {
+
+		/* update parameters */
+		orb_check(param_changed_sub, &new_data);
+
+		if (new_data || param_init_forced) {
+			param_init_forced = false;
+			/* parameters changed */
+			orb_copy(ORB_ID(parameter_update), param_changed_sub, &param_changed);
+
+			/* update parameters */
+			if (!armed.armed) {
+				if (param_get(_param_sys_type, &(current_status.system_type)) != OK) {
+					warnx("failed getting new system type");
+				}
+
+				/* disable manual override for all systems that rely on electronic stabilization */
+				if (current_status.system_type == VEHICLE_TYPE_QUADROTOR ||
+				    current_status.system_type == VEHICLE_TYPE_HEXAROTOR ||
+				    current_status.system_type == VEHICLE_TYPE_OCTOROTOR) {
+					control_mode.flag_external_manual_override_ok = false;
+
+				} else {
+					control_mode.flag_external_manual_override_ok = true;
+				}
+
+				/* check and update system / component ID */
+				param_get(_param_system_id, &(current_status.system_id));
+				param_get(_param_component_id, &(current_status.component_id));
+
+			}
+		}
+
+		orb_check(sp_man_sub, &new_data);
+
+		if (new_data) {
+			orb_copy(ORB_ID(manual_control_setpoint), sp_man_sub, &sp_man);
+		}
+
+		orb_check(sp_offboard_sub, &new_data);
+
+		if (new_data) {
+			orb_copy(ORB_ID(offboard_control_setpoint), sp_offboard_sub, &sp_offboard);
+		}
+
+		orb_check(sensor_sub, &new_data);
+
+		if (new_data) {
+			orb_copy(ORB_ID(sensor_combined), sensor_sub, &sensors);
+		}
+
+		orb_check(diff_pres_sub, &new_data);
+
+		if (new_data) {
+			orb_copy(ORB_ID(differential_pressure), diff_pres_sub, &diff_pres);
+			last_diff_pres_time = diff_pres.timestamp;
+		}
+
+		orb_check(cmd_sub, &new_data);
+
+		if (new_data) {
+			/* got command */
+			orb_copy(ORB_ID(vehicle_command), cmd_sub, &cmd);
+
+			/* handle it */
+			handle_command(status_pub, &current_status, control_mode_pub, &control_mode, &cmd, armed_pub, &armed);
+		}
+
+		/* update safety topic */
+		orb_check(safety_sub, &new_data);
+
+		if (new_data) {
+			orb_copy(ORB_ID(safety), safety_sub, &safety);
+		}
+
+		/* update global position estimate */
+		orb_check(global_position_sub, &new_data);
+
+		if (new_data) {
+			/* position changed */
+			orb_copy(ORB_ID(vehicle_global_position), global_position_sub, &global_position);
+			last_global_position_time = global_position.timestamp;
+		}
+
+		/* update local position estimate */
+		orb_check(local_position_sub, &new_data);
+
+		if (new_data) {
+			/* position changed */
+			orb_copy(ORB_ID(vehicle_local_position), local_position_sub, &local_position);
+			last_local_position_time = local_position.timestamp;
+		}
+
+		/* set the condition to valid if there has recently been a local position estimate */
+		if (hrt_absolute_time() - last_local_position_time < LOCAL_POSITION_TIMEOUT) {
+			current_status.condition_local_position_valid = true;
+		} else {
+			current_status.condition_local_position_valid = false;
+		}
+
+		/* update battery status */
+		orb_check(battery_sub, &new_data);
+		if (new_data) {
+			orb_copy(ORB_ID(battery_status), battery_sub, &battery);
+			current_status.battery_voltage = battery.voltage_v;
+			current_status.condition_battery_voltage_valid = true;
+
+			/*
+			 * Only update battery voltage estimate if system has
+			 * been running for two and a half seconds.
+			 */
+			
+		}
+
+		if (hrt_absolute_time() - start_time > 2500000 && current_status.condition_battery_voltage_valid) {
+			current_status.battery_remaining = battery_remaining_estimate_voltage(current_status.battery_voltage);
+		} else {
+			current_status.battery_voltage = 0.0f;
+		}
+
+		/* update subsystem */
+		orb_check(subsys_sub, &new_data);
+		
+		if (new_data) {
+			orb_copy(ORB_ID(subsystem_info), subsys_sub, &info);
+
+			warnx("Subsys changed: %d\n", (int)info.subsystem_type);
+
+			/* mark / unmark as present */
+			if (info.present) {
+				current_status.onboard_control_sensors_present |= info.subsystem_type;
+
+			} else {
+				current_status.onboard_control_sensors_present &= ~info.subsystem_type;
+			}
+
+			/* mark / unmark as enabled */
+			if (info.enabled) {
+				current_status.onboard_control_sensors_enabled |= info.subsystem_type;
+
+			} else {
+				current_status.onboard_control_sensors_enabled &= ~info.subsystem_type;
+			}
+
+			/* mark / unmark as ok */
+			if (info.ok) {
+				current_status.onboard_control_sensors_health |= info.subsystem_type;
+
+			} else {
+				current_status.onboard_control_sensors_health &= ~info.subsystem_type;
+			}
+		}
+
+		/* Slow but important 8 Hz checks */
+		if (counter % ((1000000 / COMMANDER_MONITORING_INTERVAL) / 8) == 0) {
+
+			/* XXX if armed */
+			if (armed.armed) {
+				/* armed, solid */
+				led_on(LED_AMBER);
+
+			} else if (armed.ready_to_arm && (counter % (1000000 / COMMANDER_MONITORING_INTERVAL) == 0)) {
+				/* ready to arm */
+				led_toggle(LED_AMBER);
+			} else if (counter % (100000 / COMMANDER_MONITORING_INTERVAL) == 0) {
+				/* not ready to arm, something is wrong */
+				led_toggle(LED_AMBER);
+			}
+
+			if (hrt_absolute_time() - gps_position.timestamp_position < 2000000) {
+
+				/* toggle GPS (blue) led at 1 Hz if GPS present but no lock, make is solid once locked */
+				if ((hrt_absolute_time() - gps_position.timestamp_position < 2000000)
+					&& (gps_position.fix_type == GPS_FIX_TYPE_3D)) {
+					/* GPS lock */
+					led_on(LED_BLUE);
+
+				} else if ((counter + 4) % (1000000 / COMMANDER_MONITORING_INTERVAL) == 0) {
+					/* no GPS lock, but GPS module is aquiring lock */
+					led_toggle(LED_BLUE);
+				}
+
+			} else {
+				/* no GPS info, don't light the blue led */
+				led_off(LED_BLUE);
+			}
+
+
+			// /* toggle GPS led at 5 Hz in HIL mode */
+			// if (current_status.flag_hil_enabled) {
+			// 	/* hil enabled */
+			// 	led_toggle(LED_BLUE);
+
+			// } else if (bat_remain < 0.3f && (low_voltage_counter > LOW_VOLTAGE_BATTERY_COUNTER_LIMIT)) {
+			// 	/* toggle arming (red) at 5 Hz on low battery or error */
+			// 	led_toggle(LED_AMBER);
+			// }
+
+		}
+
+		if (counter % (1000000 / COMMANDER_MONITORING_INTERVAL) == 0) {
+			/* compute system load */
+			uint64_t interval_runtime = system_load.tasks[0].total_runtime - last_idle_time;
+
+			if (last_idle_time > 0)
+				current_status.load = 1000 - (interval_runtime / 1000);	//system load is time spent in non-idle
+
+			last_idle_time = system_load.tasks[0].total_runtime;
+		}
+
+		
+
+		/* if battery voltage is getting lower, warn using buzzer, etc. */
+		if (current_status.condition_battery_voltage_valid && (current_status.battery_remaining < 0.15f /* XXX MAGIC NUMBER */) && (false == low_battery_voltage_actions_done)) { //TODO: add filter, or call emergency after n measurements < VOLTAGE_BATTERY_MINIMAL_MILLIVOLTS
+
+			if (low_voltage_counter > LOW_VOLTAGE_BATTERY_COUNTER_LIMIT) {
+				low_battery_voltage_actions_done = true;
+				mavlink_log_critical(mavlink_fd, "[cmd] WARNING! LOW BATTERY!");
+				current_status.battery_warning = VEHICLE_BATTERY_WARNING_WARNING;
+				tune_low_bat();
+			}
+
+			low_voltage_counter++;
+		}
+
+		/* Critical, this is rather an emergency, change state machine */
+		else if (current_status.condition_battery_voltage_valid && (current_status.battery_remaining < 0.1f /* XXX MAGIC NUMBER */) && (false == critical_battery_voltage_actions_done && true == low_battery_voltage_actions_done)) {
+			if (critical_voltage_counter > CRITICAL_VOLTAGE_BATTERY_COUNTER_LIMIT) {
+				critical_battery_voltage_actions_done = true;
+				mavlink_log_critical(mavlink_fd, "[cmd] EMERGENCY! CRITICAL BATTERY!");
+				current_status.battery_warning = VEHICLE_BATTERY_WARNING_ALERT;
+				tune_critical_bat();
+				// XXX implement state change here
+			}
+
+			critical_voltage_counter++;
+
+		} else {
+			low_voltage_counter = 0;
+			critical_voltage_counter = 0;
+		}
+
+		/* End battery voltage check */
+
+		/* If in INIT state, try to proceed to STANDBY state */
+		if (current_status.arming_state == ARMING_STATE_INIT) {
+			// XXX check for sensors
+			arming_state_transition(status_pub, &current_status, ARMING_STATE_STANDBY, armed_pub, &armed, mavlink_fd);
+		} else {
+			// XXX: Add emergency stuff if sensors are lost
+		}
+
+
+		/*
+		 * Check for valid position information.
+		 *
+		 * If the system has a valid position source from an onboard
+		 * position estimator, it is safe to operate it autonomously.
+		 * The flag_vector_flight_mode_ok flag indicates that a minimum
+		 * set of position measurements is available.
+		 */
+
+		/* store current state to reason later about a state change */
+		// bool vector_flight_mode_ok = current_status.flag_vector_flight_mode_ok;
+		bool global_pos_valid = current_status.condition_global_position_valid;
+		bool local_pos_valid = current_status.condition_local_position_valid;
+		bool airspeed_valid = current_status.condition_airspeed_valid;
+
+
+		/* check for global or local position updates, set a timeout of 2s */
+		if (hrt_absolute_time() - last_global_position_time < 2000000 && hrt_absolute_time() > 2000000) {
+			current_status.condition_global_position_valid = true;
+			// XXX check for controller status and home position as well
+
+		} else {
+			current_status.condition_global_position_valid = false;
+		}
+
+		if (hrt_absolute_time() - last_local_position_time < 2000000 && hrt_absolute_time() > 2000000) {
+			current_status.condition_local_position_valid = true;
+			// XXX check for controller status and home position as well
+
+		} else {
+			current_status.condition_local_position_valid = false;
+		}
+
+		/* Check for valid airspeed/differential pressure measurements */
+		if (hrt_absolute_time() - last_diff_pres_time < 2000000 && hrt_absolute_time() > 2000000) {
+			current_status.condition_airspeed_valid = true;
+
+		} else {
+			current_status.condition_airspeed_valid = false;
+		}
+
+		/*
+		 * Consolidate global position and local position valid flags
+		 * for vector flight mode.
+		 */
+		// if (current_status.condition_local_position_valid ||
+		//     current_status.condition_global_position_valid) {
+		// 	current_status.flag_vector_flight_mode_ok = true;
+
+		// } else {
+		// 	current_status.flag_vector_flight_mode_ok = false;
+		// }
+
+		/* consolidate state change, flag as changed if required */
+		if (global_pos_valid != current_status.condition_global_position_valid ||
+		    local_pos_valid != current_status.condition_local_position_valid ||
+		    airspeed_valid != current_status.condition_airspeed_valid) {
+			state_changed = true;
+		}
+
+		/*
+		 * Mark the position of the first position lock as return to launch (RTL)
+		 * position. The MAV will return here on command or emergency.
+		 *
+		 * Conditions:
+		 *
+		 * 	1) The system aquired position lock just now
+		 *	2) The system has not aquired position lock before
+		 *	3) The system is not armed (on the ground)
+		 */
+		// if (!current_status.flag_valid_launch_position &&
+		//     !vector_flight_mode_ok && current_status.flag_vector_flight_mode_ok &&
+		//     !current_status.flag_system_armed) {
+		// 	 first time a valid position, store it and emit it 
+
+		// 	// XXX implement storage and publication of RTL position
+		// 	current_status.flag_valid_launch_position = true;
+		// 	current_status.flag_auto_flight_mode_ok = true;
+		// 	state_changed = true;
+		// }
+
+		orb_check(gps_sub, &new_data);
+		if (new_data) {
+
+
+			orb_copy(ORB_ID(vehicle_gps_position), gps_sub, &gps_position);
+
+			/* check for first, long-term and valid GPS lock -> set home position */
+			float hdop_m = gps_position.eph_m;
+			float vdop_m = gps_position.epv_m;
+
+			/* check if gps fix is ok */
+			// XXX magic number
+			float hdop_threshold_m = 4.0f;
+			float vdop_threshold_m = 8.0f;
+
+			/*
+			 * If horizontal dilution of precision (hdop / eph)
+			 * and vertical diluation of precision (vdop / epv)
+			 * are below a certain threshold (e.g. 4 m), AND
+			 * home position is not yet set AND the last GPS
+			 * GPS measurement is not older than two seconds AND
+			 * the system is currently not armed, set home
+			 * position to the current position.
+			 */
+
+			if (gps_position.fix_type == GPS_FIX_TYPE_3D
+				&& (hdop_m < hdop_threshold_m)
+				&& (vdop_m < vdop_threshold_m) // XXX note that vdop is 0 for mtk
+				&& !home_position_set
+				&& (hrt_absolute_time() - gps_position.timestamp_position < 2000000)
+				&& !armed.armed) {
+				warnx("setting home position");
+
+				/* copy position data to uORB home message, store it locally as well */
+				home.lat = gps_position.lat;
+				home.lon = gps_position.lon;
+				home.alt = gps_position.alt;
+
+				home.eph_m = gps_position.eph_m;
+				home.epv_m = gps_position.epv_m;
+
+				home.s_variance_m_s = gps_position.s_variance_m_s;
+				home.p_variance_m = gps_position.p_variance_m;
+
+				/* announce new home position */
+				if (home_pub > 0) {
+					orb_publish(ORB_ID(home_position), home_pub, &home);
+				} else {
+					home_pub = orb_advertise(ORB_ID(home_position), &home);
+				}
+
+				/* mark home position as set */
+				home_position_set = true;
+				tune_positive();
+			}
+		}
+
+		/* ignore RC signals if in offboard control mode */
+		if (!current_status.offboard_control_signal_found_once && sp_man.timestamp != 0) {
+			/* Start RC state check */
+
+			if ((hrt_absolute_time() - sp_man.timestamp) < 100000) {
+
+				/*
+				* Check if manual control modes have to be switched
+				*/
+				if (!isfinite(sp_man.mode_switch)) {
+
+					warnx("mode sw not finite");
+					/* no valid stick position, go to default */
+					current_status.mode_switch = MODE_SWITCH_MANUAL;
+
+				} else if (sp_man.mode_switch < -STICK_ON_OFF_LIMIT) {
+
+					/* bottom stick position, go to manual mode */
+					current_status.mode_switch = MODE_SWITCH_MANUAL;
+
+				} else if (sp_man.mode_switch > STICK_ON_OFF_LIMIT) {
+
+					/* top stick position, set auto/mission for all vehicle types */
+					current_status.mode_switch = MODE_SWITCH_AUTO;
+
+				} else {
+
+					/* center stick position, set seatbelt/simple control */
+					current_status.mode_switch = MODE_SWITCH_SEATBELT;
+				}
+
+				// warnx("man ctrl mode: %d\n", (int)current_status.manual_control_mode);
+
+				/*
+				* Check if land/RTL is requested
+				*/
+				if (!isfinite(sp_man.return_switch)) {
+
+					/* this switch is not properly mapped, set default */
+					current_status.return_switch = RETURN_SWITCH_NONE;
+
+				} else if (sp_man.return_switch < -STICK_ON_OFF_LIMIT) {
+
+					/* bottom stick position, set altitude hold */
+					current_status.return_switch = RETURN_SWITCH_NONE;
+
+				} else if (sp_man.return_switch > STICK_ON_OFF_LIMIT) {
+
+					/* top stick position */
+					current_status.return_switch = RETURN_SWITCH_RETURN;
+
+				} else {
+					/* center stick position, set default */
+					current_status.return_switch = RETURN_SWITCH_NONE;
+				}
+
+				/* check mission switch  */
+				if (!isfinite(sp_man.mission_switch)) {
+
+					/* this switch is not properly mapped, set default */
+					current_status.mission_switch = MISSION_SWITCH_NONE;
+
+				} else if (sp_man.mission_switch > STICK_ON_OFF_LIMIT) {
+
+					/* top switch position */
+					current_status.mission_switch = MISSION_SWITCH_MISSION;
+
+				} else if (sp_man.mission_switch < -STICK_ON_OFF_LIMIT) {
+
+					/* bottom switch position */
+					current_status.mission_switch = MISSION_SWITCH_NONE;
+
+				} else {
+
+					/* center switch position, set default */
+					current_status.mission_switch = MISSION_SWITCH_NONE; // XXX default?
+				}
+
+				/* Now it's time to handle the stick inputs */
+				
+				switch (current_status.arming_state) {
+			
+					/* evaluate the navigation state when disarmed */
+					case ARMING_STATE_STANDBY:
+			
+						/* just manual, XXX this might depend on the return switch */
+						if (current_status.mode_switch == MODE_SWITCH_MANUAL) {
+							
+							if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_MANUAL_STANDBY, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								// These is not supposed to happen
+								warnx("ERROR: Navigation state MANUAL_STANDBY rejected");
+							}
+			
+						/* Try seatbelt or fallback to manual */
+						} else if (current_status.mode_switch == MODE_SWITCH_SEATBELT) {
+			
+							if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_SEATBELT_STANDBY, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								// fallback to MANUAL_STANDBY
+								if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_MANUAL_STANDBY, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								// These is not supposed to happen
+								warnx("ERROR: Navigation state MANUAL_STANDBY rejected");
+								}
+							}
+			
+						/* Try auto or fallback to seatbelt or even manual */
+						} else if (current_status.mode_switch == MODE_SWITCH_AUTO) {
+							
+							if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_AUTO_STANDBY, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								// first fallback to SEATBELT_STANDY
+								if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_SEATBELT_STANDBY, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+									// or fallback to MANUAL_STANDBY
+									if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_MANUAL_STANDBY, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+									// These is not supposed to happen
+									warnx("ERROR: Navigation state MANUAL_STANDBY rejected");
+									}
+								}
+							}
+						}
+			
+						break;
+			
+					/* evaluate the navigation state when armed */
+					case ARMING_STATE_ARMED:
+			
+						/* Always accept manual mode */
+						if (current_status.mode_switch == MODE_SWITCH_MANUAL) {
+
+							if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_MANUAL, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								// These is not supposed to happen
+								warnx("ERROR: Navigation state MANUAL rejected");
+							}
+			
+						/* SEATBELT_STANDBY (fallback: MANUAL) */
+						} else if (current_status.mode_switch == MODE_SWITCH_SEATBELT
+								&& current_status.return_switch == RETURN_SWITCH_NONE) {
+			
+							if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_SEATBELT, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								// fallback to MANUAL_STANDBY
+								if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_MANUAL, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								// These is not supposed to happen
+								warnx("ERROR: Navigation state MANUAL rejected");
+								}
+							}
+			
+						/* SEATBELT_DESCENT (fallback: MANUAL) */
+						} else if (current_status.mode_switch == MODE_SWITCH_SEATBELT
+								&& current_status.return_switch == RETURN_SWITCH_RETURN) {
+			
+							if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_SEATBELT_DESCENT, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								// fallback to MANUAL_STANDBY
+								if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_MANUAL, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								// These is not supposed to happen
+								warnx("ERROR: Navigation state MANUAL rejected");
+								}
+							}
+			
+						/* AUTO_LOITER (fallback: SEATBELT, MANUAL) */
+						} else if (current_status.mode_switch == MODE_SWITCH_AUTO
+								&& current_status.return_switch == RETURN_SWITCH_NONE
+								&& current_status.mission_switch == MISSION_SWITCH_NONE) {
+			
+							/* we might come from the disarmed state AUTO_STANDBY */
+							if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_AUTO_READY, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_SEATBELT, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+									// fallback to MANUAL_STANDBY
+									if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_MANUAL, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+									// These is not supposed to happen
+									warnx("ERROR: Navigation state MANUAL rejected");
+									}
+								}
+							/* or from some other armed state like SEATBELT or MANUAL */
+							} else if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_AUTO_LOITER, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_SEATBELT, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+									// fallback to MANUAL_STANDBY
+									if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_MANUAL, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+									// These is not supposed to happen
+									warnx("ERROR: Navigation state MANUAL rejected");
+									}
+								}
+							}
+			
+						/* AUTO_MISSION (fallback: SEATBELT, MANUAL) */
+						} else if (current_status.mode_switch == MODE_SWITCH_AUTO
+								&& current_status.return_switch == RETURN_SWITCH_NONE
+								&& current_status.mission_switch == MISSION_SWITCH_MISSION) {
+							
+							if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_AUTO_MISSION, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_SEATBELT, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+									// fallback to MANUAL_STANDBY
+									if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_MANUAL, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+									// These is not supposed to happen
+									warnx("ERROR: Navigation state MANUAL rejected");
+									}
+								}
+							}
+			
+						/* AUTO_RTL (fallback: SEATBELT_DESCENT, MANUAL) */
+						} else if (current_status.mode_switch == MODE_SWITCH_AUTO
+								&& current_status.return_switch == RETURN_SWITCH_RETURN
+								&& (current_status.mission_switch == MISSION_SWITCH_NONE || current_status.mission_switch == MISSION_SWITCH_MISSION)) {
+			
+							if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_AUTO_RTL, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+								if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_SEATBELT_DESCENT, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+									// fallback to MANUAL_STANDBY
+									if (navigation_state_transition(status_pub, &current_status, NAVIGATION_STATE_MANUAL, control_mode_pub, &control_mode, mavlink_fd) != OK) {
+									// These is not supposed to happen
+									warnx("ERROR: Navigation state MANUAL rejected");
+									}
+								}
+							}
+						}
+						break;
+
+						// XXX we might be missing something that triggers a transition from RTL to LAND
+			
+					case ARMING_STATE_ARMED_ERROR:
+			
+						// XXX work out fail-safe scenarios
+						break;
+			
+					case ARMING_STATE_STANDBY_ERROR:
+			
+						// XXX work out fail-safe scenarios
+						break;
+			
+					case ARMING_STATE_REBOOT:
+			
+						// XXX I don't think we should end up here
+						break;
+			
+					case ARMING_STATE_IN_AIR_RESTORE:
+			
+						// XXX not sure what to do here
+						break;
+					default:
+						break;
+				}
+				/* handle the case where RC signal was regained */
+				if (!current_status.rc_signal_found_once) {
+					current_status.rc_signal_found_once = true;
+					mavlink_log_critical(mavlink_fd, "DETECTED RC SIGNAL FIRST TIME.");
+
+				} else {
+					if (current_status.rc_signal_lost) {
+						mavlink_log_critical(mavlink_fd, "[cmd] RECOVERY - RC SIGNAL GAINED!");
+					}
+				}
+
+				/*
+				* Check if left stick is in lower left position --> switch to standby state.
+				* Do this only for multirotors, not for fixed wing aircraft.
+				*/
+				if ((sp_man.yaw < -STICK_ON_OFF_LIMIT) && (sp_man.throttle < STICK_THRUST_RANGE * 0.1f)) {
+
+					if (stick_off_counter > STICK_ON_OFF_COUNTER_LIMIT) {
+
+						if((current_status.system_type == VEHICLE_TYPE_QUADROTOR) ||
+						 (current_status.system_type == VEHICLE_TYPE_HEXAROTOR) ||
+						 (current_status.system_type == VEHICLE_TYPE_OCTOROTOR)
+						) {
+							if (control_mode.flag_control_position_enabled || control_mode.flag_control_velocity_enabled) {
+								mavlink_log_critical(mavlink_fd, "DISARM DENY, go manual mode first");
+								tune_negative();
+							} else {
+								arming_state_transition(status_pub, &current_status, ARMING_STATE_STANDBY, armed_pub, &armed, mavlink_fd);
+								tune_positive();
+							}
+							
+						} else {
+							mavlink_log_critical(mavlink_fd, "DISARM not allowed");
+							tune_negative();
+						}
+						stick_off_counter = 0;
+
+					} else {
+						stick_off_counter++;
+						stick_on_counter = 0;
+					}
+				}
+
+				/* check if left stick is in lower right position and we're in manual --> arm */
+				if (sp_man.yaw > STICK_ON_OFF_LIMIT &&
+					sp_man.throttle < STICK_THRUST_RANGE * 0.1f) {
+					if (stick_on_counter > STICK_ON_OFF_COUNTER_LIMIT) {
+						arming_state_transition(status_pub, &current_status, ARMING_STATE_ARMED, armed_pub, &armed, mavlink_fd);
+						stick_on_counter = 0;
+						tune_positive();
+
+					} else {
+						stick_on_counter++;
+						stick_off_counter = 0;
+					}
+				}
+
+				current_status.rc_signal_cutting_off = false;
+				current_status.rc_signal_lost = false;
+				current_status.rc_signal_lost_interval = 0;
+
+			} else {
+
+				/* print error message for first RC glitch and then every 5 s / 5000 ms) */
+				if (!current_status.rc_signal_cutting_off || ((hrt_absolute_time() - last_print_time) > 5000000)) {
+					/* only complain if the offboard control is NOT active */
+					current_status.rc_signal_cutting_off = true;
+					mavlink_log_critical(mavlink_fd, "CRITICAL - NO REMOTE SIGNAL!");
+
+					if (!current_status.rc_signal_cutting_off) {
+						printf("Reason: not rc_signal_cutting_off\n");
+					} else {
+						printf("last print time: %llu\n", last_print_time);
+					}
+
+					last_print_time = hrt_absolute_time();
+				}
+
+				/* flag as lost and update interval since when the signal was lost (to initiate RTL after some time) */
+				current_status.rc_signal_lost_interval = hrt_absolute_time() - sp_man.timestamp;
+
+				/* if the RC signal is gone for a full second, consider it lost */
+				if (current_status.rc_signal_lost_interval > 1000000) {
+					current_status.rc_signal_lost = true;
+					current_status.failsave_lowlevel = true;
+					state_changed = true;
+				}
+
+				// if (hrt_absolute_time() - current_status.failsave_ll_start_time > failsafe_lowlevel_timeout_ms*1000) {
+				// 	publish_armed_status(&current_status);
+				// }
+			}
+		}
+
+
+
+
+		/* End mode switch */
+
+		/* END RC state check */
+
+
+		/* State machine update for offboard control */
+		if (!current_status.rc_signal_found_once && sp_offboard.timestamp != 0) {
+			if ((hrt_absolute_time() - sp_offboard.timestamp) < 5000000) {
+
+				// /* decide about attitude control flag, enable in att/pos/vel */
+				// bool attitude_ctrl_enabled = (sp_offboard.mode == OFFBOARD_CONTROL_MODE_DIRECT_ATTITUDE ||
+				// 				  sp_offboard.mode == OFFBOARD_CONTROL_MODE_DIRECT_VELOCITY ||
+				// 				  sp_offboard.mode == OFFBOARD_CONTROL_MODE_DIRECT_POSITION);
+
+				// /* decide about rate control flag, enable it always XXX (for now) */
+				// bool rates_ctrl_enabled = true;
+
+				// /* set up control mode */
+				// if (current_status.flag_control_attitude_enabled != attitude_ctrl_enabled) {
+				// 	current_status.flag_control_attitude_enabled = attitude_ctrl_enabled;
+				// 	state_changed = true;
+				// }
+
+				// if (current_status.flag_control_rates_enabled != rates_ctrl_enabled) {
+				// 	current_status.flag_control_rates_enabled = rates_ctrl_enabled;
+				// 	state_changed = true;
+				// }
+
+				// /* handle the case where offboard control signal was regained */
+				// if (!current_status.offboard_control_signal_found_once) {
+				// 	current_status.offboard_control_signal_found_once = true;
+				// 	/* enable offboard control, disable manual input */
+				// 	current_status.flag_control_manual_enabled = false;
+				// 	current_status.flag_control_offboard_enabled = true;
+				// 	state_changed = true;
+				// 	tune_positive();
+
+				// 	mavlink_log_critical(mavlink_fd, "DETECTED OFFBOARD SIGNAL FIRST");
+
+				// } else {
+				// 	if (current_status.offboard_control_signal_lost) {
+				// 		mavlink_log_critical(mavlink_fd, "RECOVERY OFFBOARD CONTROL");
+				// 		state_changed = true;
+				// 		tune_positive();
+				// 	}
+				// }
+
+				current_status.offboard_control_signal_weak = false;
+				current_status.offboard_control_signal_lost = false;
+				current_status.offboard_control_signal_lost_interval = 0;
+
+				// XXX check if this is correct
+				/* arm / disarm on request */
+				if (sp_offboard.armed && !armed.armed) {
+
+					arming_state_transition(status_pub, &current_status, ARMING_STATE_ARMED, armed_pub, &armed, mavlink_fd);
+
+				} else if (!sp_offboard.armed && armed.armed) {
+
+					arming_state_transition(status_pub, &current_status, ARMING_STATE_STANDBY, armed_pub, &armed, mavlink_fd);
+				}
+
+			} else {
+
+				/* print error message for first RC glitch and then every 5 s / 5000 ms) */
+				if (!current_status.offboard_control_signal_weak || ((hrt_absolute_time() - last_print_time) > 5000000)) {
+					current_status.offboard_control_signal_weak = true;
+					mavlink_log_critical(mavlink_fd, "CRIT:NO OFFBOARD CONTROL!");
+					last_print_time = hrt_absolute_time();
+				}
+
+				/* flag as lost and update interval since when the signal was lost (to initiate RTL after some time) */
+				current_status.offboard_control_signal_lost_interval = hrt_absolute_time() - sp_offboard.timestamp;
+
+				/* if the signal is gone for 0.1 seconds, consider it lost */
+				if (current_status.offboard_control_signal_lost_interval > 100000) {
+					current_status.offboard_control_signal_lost = true;
+					current_status.failsave_lowlevel_start_time = hrt_absolute_time();
+					tune_positive();
+
+					/* kill motors after timeout */
+					if (hrt_absolute_time() - current_status.failsave_lowlevel_start_time > failsafe_lowlevel_timeout_ms * 1000) {
+						current_status.failsave_lowlevel = true;
+						state_changed = true;
+					}
+				}
+			}
+		}
+
+
+
+
+		current_status.counter++;
+		current_status.timestamp = hrt_absolute_time();
+
+
+		// XXX this is missing
+		/* If full run came back clean, transition to standby */
+		// if (current_status.state_machine == SYSTEM_STATE_PREFLIGHT &&
+		//     current_status.flag_preflight_gyro_calibration == false &&
+		//     current_status.flag_preflight_mag_calibration == false &&
+		//     current_status.flag_preflight_accel_calibration == false) {
+		// 	/* All ok, no calibration going on, go to standby */
+		// 	do_state_update(status_pub, &current_status, mavlink_fd, SYSTEM_STATE_STANDBY);
+		// }
+
+		/* publish at least with 1 Hz */
+		if (counter % (1000000 / COMMANDER_MONITORING_INTERVAL) == 0 || state_changed) {
+
+			orb_publish(ORB_ID(vehicle_status), status_pub, &current_status);
+			state_changed = false;
+		}
+
+
+
+		/* Store old modes to detect and act on state transitions */
+		voltage_previous = current_status.battery_voltage;
+
+
+		/* play tone according to evaluation result */
+		/* check if we recently armed */
+		if (!arm_tune_played && armed.armed && ( !safety.safety_switch_available || (safety.safety_off && safety.safety_switch_available))) {
+			if (tune_arm() == OK)
+				arm_tune_played = true;
+
+		/* Trigger audio event for low battery */
+		} else if (current_status.battery_remaining < 0.1f && current_status.condition_battery_voltage_valid) {
+			if (tune_critical_bat() == OK)
+				battery_tune_played = true;
+		} else if (current_status.battery_remaining < 0.2f && current_status.condition_battery_voltage_valid) {
+			if (tune_low_bat() == OK)
+				battery_tune_played = true;
+		} else if(battery_tune_played) {
+			tune_stop();
+			battery_tune_played = false;
+		}
+
+		/* reset arm_tune_played when disarmed */
+		if (!(armed.armed && ( !safety.safety_switch_available || (safety.safety_off && safety.safety_switch_available)))) {
+			arm_tune_played = false;
+		}
+
+
+		/* XXX use this voltage_previous */
+		fflush(stdout);
+		counter++;
+		usleep(COMMANDER_MONITORING_INTERVAL);
+	}
+
+	/* wait for threads to complete */
+	pthread_join(commander_low_prio_thread, NULL);
+
+	/* close fds */
+	led_deinit();
+	buzzer_deinit();
+	close(sp_man_sub);
+	close(sp_offboard_sub);
+	close(local_position_sub);
+	close(global_position_sub);
+	close(gps_sub);
+	close(sensor_sub);
+	close(safety_sub);
+	close(cmd_sub);
+	close(subsys_sub);
+	close(diff_pres_sub);
+	close(param_changed_sub);
+	close(battery_sub);
+
+	warnx("exiting");
+	fflush(stdout);
+
+	thread_running = false;
+
+	return 0;
+}
+
+
+void *commander_low_prio_loop(void *arg)
+{
+	/* Set thread name */
+	prctl(PR_SET_NAME, "commander low prio", getpid());
+
+	while (!thread_should_exit) {
+
+		switch (low_prio_task) {
+
+			case LOW_PRIO_TASK_PARAM_LOAD:
+
+				if (0 == param_load_default()) {
+					mavlink_log_info(mavlink_fd, "Param load success");
+				} else {
+					mavlink_log_critical(mavlink_fd, "Param load ERROR");
+					tune_error();
+				}
+				low_prio_task = LOW_PRIO_TASK_NONE;
+				break;
+
+			case LOW_PRIO_TASK_PARAM_SAVE:
+
+				if (0 == param_save_default()) {
+					mavlink_log_info(mavlink_fd, "Param save success");
+				} else {
+					mavlink_log_critical(mavlink_fd, "Param save ERROR");
+					tune_error();
+				}
+				low_prio_task = LOW_PRIO_TASK_NONE;
+				break;
+
+			case LOW_PRIO_TASK_GYRO_CALIBRATION:
+
+				do_gyro_calibration(mavlink_fd);
+
+				low_prio_task = LOW_PRIO_TASK_NONE;
+				break;
+
+			case LOW_PRIO_TASK_MAG_CALIBRATION:
+
+				do_mag_calibration(mavlink_fd);
+
+				low_prio_task = LOW_PRIO_TASK_NONE;
+				break;
+
+			case LOW_PRIO_TASK_ALTITUDE_CALIBRATION:
+
+				// do_baro_calibration(mavlink_fd);
+
+			case LOW_PRIO_TASK_RC_CALIBRATION:
+
+				// do_rc_calibration(mavlink_fd);
+
+				low_prio_task = LOW_PRIO_TASK_NONE;
+				break;
+
+			case LOW_PRIO_TASK_ACCEL_CALIBRATION:
+
+				do_accel_calibration(mavlink_fd);
+
+				low_prio_task = LOW_PRIO_TASK_NONE;
+				break;
+
+			case LOW_PRIO_TASK_AIRSPEED_CALIBRATION:
+
+				do_airspeed_calibration(mavlink_fd);
+
+				low_prio_task = LOW_PRIO_TASK_NONE;
+				break;
+
+			case LOW_PRIO_TASK_NONE:
+			default:
+				/* slow down to 10Hz */
+				usleep(100000);
+				break;
+		}
+
+	}
+
+	return 0;
+}