MAVLink app: Add option to configure broadcast, default to off

src/modules/mavlink/mavlink_main.cpp

@@ -237,12 +237,15 @@ Mavlink::Mavlink() :
 	_message_buffer_mutex {},
 	_send_mutex {},
 	_param_initialized(false),
-	_param_system_id(0),
+	_logging_enabled(false),
-	_param_component_id(0),
+	_broadcast_mode(Mavlink::BROADCAST_MODE_OFF),
-	_param_radio_id(0),
+	_param_system_id(PARAM_INVALID),
-	_param_system_type(MAV_TYPE_FIXED_WING),
+	_param_component_id(PARAM_INVALID),
-	_param_use_hil_gps(0),
+	_param_radio_id(PARAM_INVALID),
-	_param_forward_externalsp(0),
+	_param_system_type(PARAM_INVALID),
+	_param_use_hil_gps(PARAM_INVALID),
+	_param_forward_externalsp(PARAM_INVALID),
+	_param_broadcast(PARAM_INVALID),
 	_system_type(0),
 
 	/* performance counters */
@@ -539,6 +542,7 @@ void Mavlink::mavlink_update_system(void)
 		_param_system_type = param_find("MAV_TYPE");
 		_param_use_hil_gps = param_find("MAV_USEHILGPS");
 		_param_forward_externalsp = param_find("MAV_FWDEXTSP");
+		_param_broadcast = param_find("MAV_BROADCAST");
 
 		/* test param - needs to be referenced, but is unused */
 		(void)param_find("MAV_TEST_PAR");
@@ -597,6 +601,8 @@ void Mavlink::mavlink_update_system(void)
 	int32_t forward_externalsp;
 	param_get(_param_forward_externalsp, &forward_externalsp);
 
+	param_get(_param_broadcast, &_broadcast_mode);
+
 	_forward_externalsp = (bool)forward_externalsp;
 }
 
@@ -889,7 +895,7 @@ Mavlink::send_packet()
 		struct telemetry_status_s &tstatus = get_rx_status();
 
 		/* resend message via broadcast if no valid connection exists */
-		if ((_mode != MAVLINK_MODE_ONBOARD) &&
+		if ((_mode != MAVLINK_MODE_ONBOARD) && broadcast_enabled() &&
 			(!get_client_source_initialized()
 			|| (hrt_elapsed_time(&tstatus.heartbeat_time) > 3 * 1000 * 1000))) {
 
@@ -2475,6 +2481,26 @@ Mavlink::stream_command(int argc, char *argv[])
 	return OK;
 }
 
+void
+Mavlink::set_boot_complete()
+{
+	_boot_complete = true;
+
+#ifdef __PX4_POSIX
+	Mavlink *inst;
+	LL_FOREACH(::_mavlink_instances, inst) {
+		if ((inst->get_mode() != MAVLINK_MODE_ONBOARD) &&
+			(!inst->broadcast_enabled()) &&
+			((inst->get_protocol() == UDP) || (inst->get_protocol() == TCP))) {
+			printf("\n\n   **********   NETWORK BROADCAST NOT ENABLED   **********\n" \
+				"   The drone will only connect to localhost (excluding VMs).\n" \
+				"   Run 'pxh> param set MAV_BROADCAST 1' to enable.\n");
+		}
+	}
+#endif
+
+}
+
 static void usage()
 {
 	warnx("usage: mavlink {start|stop|stream} [-d device] [-u network_port] [-o remote_port] [-t partner_ip] [-b baudrate]\n\t[-r rate][-m mode] [-s stream] [-f] [-p] [-v] [-w] [-x]");

src/modules/mavlink/mavlink_main.h

@@ -164,6 +164,11 @@ public:
 		MAVLINK_MODE_CONFIG
 	};
 
+	enum BROADCAST_MODE {
+		BROADCAST_MODE_OFF = 0,
+		BROADCAST_MODE_ON
+	};
+
 	void			set_mode(enum MAVLINK_MODE);
 	enum MAVLINK_MODE	get_mode() { return _mode; }
 
@@ -181,13 +186,15 @@ public:
 
 	void			set_config_link_on(bool on) { _config_link_on = on; }
 
+	bool			broadcast_enabled() { return _broadcast_mode > BROADCAST_MODE_OFF; }
+
 	/**
 	 * Set the boot complete flag on all instances
 	 *
 	 * Setting the flag unblocks parameter transmissions, which are gated
 	 * beforehand to ensure that the system is fully initialized.
 	 */
-	static void		set_boot_complete() { _boot_complete = true; }
+	static void		set_boot_complete();
 
 	/**
 	 * Get the free space in the transmit buffer
@@ -504,6 +511,7 @@ private:
 
 	bool			_param_initialized;
 	bool			_logging_enabled;
+	uint32_t		_broadcast_mode;
 
 	param_t			_param_system_id;
 	param_t			_param_component_id;
@@ -512,6 +520,7 @@ private:
 	param_t			_param_system_type;
 	param_t			_param_use_hil_gps;
 	param_t			_param_forward_externalsp;
+	param_t			_param_broadcast;
 
 	unsigned		_system_type;
 	static bool		_config_link_on;

src/modules/mavlink/mavlink_params.c

@@ -99,6 +99,18 @@ PARAM_DEFINE_INT32(MAV_USEHILGPS, 0);
  */
 PARAM_DEFINE_INT32(MAV_FWDEXTSP, 1);
 
+/**
+ * Broadcast heartbeats on local network
+ *
+ * This allows a ground control station to automatically find the drone
+ * on the local network.
+ *
+ * @value 0 Never broadcast
+ * @value 1 Always broadcast
+ * @group MAVLink
+ */
+PARAM_DEFINE_INT32(MAV_BROADCAST, 0);
+
 /**
  * Test parameter
  *