q_estimator: correctly handle loss of external yaw estimation

src/modules/attitude_estimator_q/attitude_estimator_q_main.cpp

@@ -361,16 +361,21 @@ void AttitudeEstimatorQ::task_main()
 					// Hence Rvis must be transposed having (Rwr)' * Vw
 					// Rrw * Vw = vn. This way we have consistency
 					_vision_hdg = Rvis.transpose() * v;
-
+				}
+			}
+		}
 		// vision external heading usage (ATT_EXT_HDG_M 1)
 		if (_ext_hdg_mode == 1) {
 			// Check for timeouts on data
-						_ext_hdg_good = vision.timestamp > 0 && (hrt_elapsed_time(&vision.timestamp) < 500000);
+			uint64_t time_topic;
-					}
+			if (orb_stat(_vision_odom_sub, &time_topic)) {
-				}
+				/* error getting last topic publication time */
+				time_topic = 0;
 			}
+			_ext_hdg_good = time_topic > 0 && (hrt_elapsed_time(&time_topic) < 500000);
 		}
 
+
 		bool mocap_updated = false;
 		orb_check(_mocap_odom_sub, &mocap_updated);
 
@@ -393,14 +398,18 @@ void AttitudeEstimatorQ::task_main()
 					// Hence Rmoc must be transposed having (Rwr)' * Vw
 					// Rrw * Vw = vn. This way we have consistency
 					_mocap_hdg = Rmoc.transpose() * v;
-
+				}
+			}
+		}
 		// Motion Capture external heading usage (ATT_EXT_HDG_M 2)
 		if (_ext_hdg_mode == 2) {
 			// Check for timeouts on data
-						_ext_hdg_good = mocap.timestamp > 0 && (hrt_elapsed_time(&mocap.timestamp) < 500000);
+			uint64_t time_topic;
-					}
+			if (orb_stat(_mocap_odom_sub, &time_topic)) {
-				}
+				/* error getting last topic publication time */
+				time_topic = 0;
 			}
+			_ext_hdg_good = time_topic > 0 && (hrt_elapsed_time(&time_topic) < 500000);
 		}
 
 		bool gpos_updated = false;