Plane: added reporting of AHRS health

ArduPlane/GCS_Mavlink.pde

 // -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
 
 // default sensors are present and healthy: gyro, accelerometer, barometer, rate_control, attitude_stabilization, yaw_position, altitude control, x/y position control, motor_control
-#define MAVLINK_SENSOR_PRESENT_DEFAULT (MAV_SYS_STATUS_SENSOR_3D_GYRO | MAV_SYS_STATUS_SENSOR_3D_ACCEL | MAV_SYS_STATUS_SENSOR_ABSOLUTE_PRESSURE | MAV_SYS_STATUS_SENSOR_ANGULAR_RATE_CONTROL | MAV_SYS_STATUS_SENSOR_ATTITUDE_STABILIZATION | MAV_SYS_STATUS_SENSOR_YAW_POSITION | MAV_SYS_STATUS_SENSOR_Z_ALTITUDE_CONTROL | MAV_SYS_STATUS_SENSOR_XY_POSITION_CONTROL | MAV_SYS_STATUS_SENSOR_MOTOR_OUTPUTS)
+#define MAVLINK_SENSOR_PRESENT_DEFAULT (MAV_SYS_STATUS_SENSOR_3D_GYRO | MAV_SYS_STATUS_SENSOR_3D_ACCEL | MAV_SYS_STATUS_SENSOR_ABSOLUTE_PRESSURE | MAV_SYS_STATUS_SENSOR_ANGULAR_RATE_CONTROL | MAV_SYS_STATUS_SENSOR_ATTITUDE_STABILIZATION | MAV_SYS_STATUS_SENSOR_YAW_POSITION | MAV_SYS_STATUS_SENSOR_Z_ALTITUDE_CONTROL | MAV_SYS_STATUS_SENSOR_XY_POSITION_CONTROL | MAV_SYS_STATUS_SENSOR_MOTOR_OUTPUTS | MAV_SYS_STATUS_AHRS)
 
 // use this to prevent recursion during sensor init
 static bool in_mavlink_delay;
@@ -217,6 +217,11 @@ static NOINLINE void send_extended_status1(mavlink_channel_t chan)
                                                          MAV_SYS_STATUS_SENSOR_DIFFERENTIAL_PRESSURE);
     control_sensors_health |= MAV_SYS_STATUS_GEOFENCE;
 
+    if (!ahrs.healthy()) {
+        // AHRS subsystem is unhealthy
+        control_sensors_health &= ~MAV_SYS_STATUS_AHRS;
+    }
+
     if (g.compass_enabled && compass.healthy(0) && ahrs.use_compass()) {
         control_sensors_health |= MAV_SYS_STATUS_SENSOR_3D_MAG;
     }