Failsafe throttle when RC is lost is now a parameter

apps/multirotor_att_control/multirotor_att_control_main.c

@@ -68,10 +68,13 @@
 
 #include <systemlib/perf_counter.h>
 #include <systemlib/systemlib.h>
+#include <systemlib/param/param.h>
 
 #include "multirotor_attitude_control.h"
 #include "multirotor_rate_control.h"
 
+PARAM_DEFINE_FLOAT(MC_RCLOSS_THROT, 0.0f);
+
 __EXPORT int multirotor_att_control_main(int argc, char *argv[]);
 
 static bool thread_should_exit;
@@ -142,6 +145,9 @@ mc_thread_main(int argc, char *argv[])
 	bool flag_system_armed = false;
 	bool man_yaw_zero_once = false;
 
+	param_t failsafe_throttle_handle = param_find("MC_RCLOSS_THROT");
+	float failsafe_throttle = 0.0f;
+
 	while (!thread_should_exit) {
 
 		/* wait for a sensor update, check for exit condition every 500 ms */
@@ -228,10 +234,11 @@ mc_thread_main(int argc, char *argv[])
 				att_sp.thrust = manual.throttle;
 
 				if(state.rc_signal_lost) {
+					param_get(failsafe_throttle_handle, &failsafe_throttle);
 					att_sp.roll_body = 0.0f;
 					att_sp.pitch_body = 0.0f;
 					att_sp.yaw_body = 0.0f;
-					att_sp.thrust = 0.4f;
+					att_sp.thrust = failsafe_throttle;
 				}
 
 				att_sp.timestamp = hrt_absolute_time();