timesync: Add uORB topic, general fixes

src/modules/mavlink/mavlink_receiver.cpp

@@ -121,6 +121,7 @@ MavlinkReceiver::MavlinkReceiver(Mavlink *parent) :
 	_rc_pub(-1),
 	_manual_pub(-1),
 	_land_detector_pub(-1),
+	_time_offset_pub(-1),
 	_control_mode_sub(orb_subscribe(ORB_ID(vehicle_control_mode))),
 	_hil_frames(0),
 	_old_timestamp(0),
@@ -729,8 +730,8 @@ MavlinkReceiver::handle_message_vision_position_estimate(mavlink_message_t *msg)
 	// Use the component ID to identify the vision sensor
 	vision_position.id = msg->compid;
 
-	vision_position.timestamp_boot = to_hrt(pos.usec); // Synced time
-	vision_position.timestamp_computer = pos.usec;
+	vision_position.timestamp_boot = hrt_absolute_time(); // Monotonic time
+	vision_position.timestamp_computer = sync_stamp(pos.usec); // Synced time
 	vision_position.x = pos.x;
 	vision_position.y = pos.y;
 	vision_position.z = pos.z;
@@ -1013,6 +1014,9 @@ MavlinkReceiver::handle_message_timesync(mavlink_message_t *msg)
 	mavlink_timesync_t tsync;
 	mavlink_msg_timesync_decode(msg, &tsync);
 
+	struct time_offset_s tsync_offset;
+	memset(&tsync_offset, 0, sizeof(tsync_offset));
+
 	uint64_t now_ns = hrt_absolute_time() * 1000LL ;
 
 	if (tsync.tc1 == 0) {
@@ -1039,6 +1043,15 @@ MavlinkReceiver::handle_message_timesync(mavlink_message_t *msg)
 		}
 	}
 
+	tsync_offset.offset_ns = _time_offset ;
+
+	if (_time_offset_pub < 0) {
+		_time_offset_pub = orb_advertise(ORB_ID(time_offset), &tsync_offset);
+
+	} else {
+		orb_publish(ORB_ID(time_offset), _time_offset_pub, &tsync_offset);
+	}
+
 }
 
 void
@@ -1522,9 +1535,12 @@ void MavlinkReceiver::print_status()
 
 }
 
-uint64_t MavlinkReceiver::to_hrt(uint64_t usec)
+uint64_t MavlinkReceiver::sync_stamp(uint64_t usec)
 {
-	return usec - (_time_offset / 1000) ;
+	if(_time_offset > 0)
+		return usec - (_time_offset / 1000) ;
+	else
+		return hrt_absolute_time();
 }
 
 

src/modules/mavlink/mavlink_receiver.h

@@ -73,6 +73,7 @@
 #include <uORB/topics/airspeed.h>
 #include <uORB/topics/battery_status.h>
 #include <uORB/topics/vehicle_force_setpoint.h>
+#include <uORB/topics/time_offset.h>
 
 #include "mavlink_ftp.h"
 
@@ -138,9 +139,10 @@ private:
 	void *receive_thread(void *arg);
 
 	/**
-	* Convert remote nsec timestamp to local hrt time (usec)
+	* Convert remote timestamp to local hrt time (usec)
+	* Use timesync if available, monotonic boot time otherwise
 	*/
-	uint64_t to_hrt(uint64_t nsec);
+	uint64_t sync_stamp(uint64_t usec);
 	/**
 	* Exponential moving average filter to smooth time offset
 	*/
@@ -177,6 +179,7 @@ private:
 	orb_advert_t _rc_pub;
 	orb_advert_t _manual_pub;
 	orb_advert_t _land_detector_pub;
+	orb_advert_t _time_offset_pub;
 	int _control_mode_sub;
 	int _hil_frames;
 	uint64_t _old_timestamp;

src/modules/uORB/objects_common.cpp

@@ -250,3 +250,7 @@ ORB_DEFINE(wind_estimate, struct wind_estimate_s);
 
 #include "topics/rc_parameter_map.h"
 ORB_DEFINE(rc_parameter_map, struct rc_parameter_map_s);
+
+#include "topics/time_offset.h"
+ORB_DEFINE(time_offset, struct time_offset_s);
+

src/modules/uORB/topics/time_offset.h

@@ -0,0 +1,67 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2015 PX4 Development Team. All rights reserved.
+ *
+ * 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 time_offset.h
+ * Time synchronisation offset
+ */
+
+#ifndef TOPIC_TIME_OFFSET_H_
+#define TOPIC_TIME_OFFSET_H_
+
+#include <stdint.h>
+#include <stdbool.h>
+#include "../uORB.h"
+
+/**
+ * @addtogroup topics
+ * @{
+ */
+
+/**
+ * Timesync offset for synchronisation with companion computer, GCS, etc.
+ */
+struct time_offset_s {
+
+	uint64_t offset_ns;		/**< time offset between companion system and PX4, in nanoseconds */
+
+};
+
+/**
+ * @}
+ */
+
+/* register this as object request broker structure */
+ORB_DECLARE(time_offset);
+
+#endif /* TOPIC_TIME_OFFSET_H_ */