Added safety status feedback, disallow arming of a rotary wing with engaged safety

src/modules/uORB/objects_common.cpp

@@ -154,3 +154,7 @@ ORB_DEFINE(actuator_outputs_3, struct actuator_outputs_s);
 
 #include "topics/debug_key_value.h"
 ORB_DEFINE(debug_key_value, struct debug_key_value_s);
+
+/* status of the system safety device */
+#include "topics/safety.h"
+ORB_DEFINE(safety, struct safety_s);

src/modules/uORB/topics/actuator_controls.h

@@ -68,9 +68,10 @@ ORB_DECLARE(actuator_controls_3);
 
 /** global 'actuator output is live' control. */
 struct actuator_armed_s {
-	bool	armed;		/**< Set to true if system is armed */
-	bool	ready_to_arm;	/**< Set to true if system is ready to be armed */
-	bool	lockdown;	/**< Set to true if actuators are forced to being disabled (due to emergency or HIL) */
+	bool	armed;			/**< Set to true if system is armed */
+	bool	ready_to_arm;		/**< Set to true if system is ready to be armed */
+	bool	throttle_locked;	/**< Set to true if the trottle is locked to zero */
+	bool	lockdown;		/**< Set to true if actuators are forced to being disabled (due to emergency or HIL) */
 };
 
 ORB_DECLARE(actuator_armed);

src/modules/uORB/topics/safety.h

@@ -0,0 +1,60 @@
+/****************************************************************************
+ *
+ *   Copyright (c) 2013 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 safety.h
+ *
+ * Status of an attached safety device
+ */
+
+#ifndef TOPIC_SAFETY_H
+#define TOPIC_SAFETY_H
+
+#include <stdint.h>
+#include "../uORB.h"
+
+enum SAFETY_STATUS {
+	SAFETY_STATUS_NOT_PRESENT,
+	SAFETY_STATUS_SAFE,
+	SAFETY_STATUS_UNLOCKED
+};
+
+struct safety_s {
+	uint64_t timestamp;			/**< output timestamp in us since system boot */
+	enum SAFETY_STATUS status;
+};
+
+/* actuator output sets; this list can be expanded as more drivers emerge */
+ORB_DECLARE(safety);
+
+#endif /* TOPIC_SAFETY_H */

src/modules/uORB/topics/vehicle_status.h

@@ -214,6 +214,8 @@ struct vehicle_status_s
 	bool flag_valid_launch_position;		/**< indicates a valid launch position */
 	bool flag_valid_home_position;			/**< indicates a valid home position (a valid home position is not always a valid launch) */
 	bool flag_airspeed_valid;			/**< set to true by the commander app if there is a valid airspeed measurement available */
+	bool flag_safety_present;			/**< indicates that a safety switch is present */
+	bool flag_safety_safe;				/**< safety switch is in safe position */
 };
 
 /**