FSX Help for Sending Waypoint Dynamically

[FSXProjectSam]

Hi all:

First time developing using simconnect.

I am trying to update new waypoint in front of the AI aircraft as the AI aircraft is flying. I see that when I send the first waypoint, AI aircraft will takeoff and fly towards it, but when I try to send another waypoint, I get exception 19 (invalid data size?).

I basically have a function (as a test) that will send a single waypoint by a button click. First time, no exception, everythings cool. Then after the aircraft is in the air on its way to the single waypoint, I call this function again by subsequent button clicks (right now for test I use same waypoint), I get exception 19. Even if I use a different waypoint (by another button click), I get the same.

Basic code is here

private void set_Single_Waypoint(double lat, double lon, double alt, double speed, DEFINITIONS d)
{
simconnect.AddToDataDefinition(d, "AI WAYPOINT LIST", "number", SIMCONNECT_DATATYPE.WAYPOINT, 0.0f, SimConnect.SIMCONNECT_UNUSED);
SIMCONNECT_DATA_WAYPOINT[] wp = new SIMCONNECT_DATA_WAYPOINT[1];

wp[0].Flags = (uint)SIMCONNECT_WAYPOINT_FLAGS.SPEED_REQUESTED;
wp[0].Altitude = 1000;
wp[0].Latitude = 47.445501972979;// 47 + (27.79 / 60);
wp[0].Longitude = -122.308007293086;// -122 - (18.46 / 60);
wp[0].ktsSpeed = 100;


Object[] objv1 = new Object[wp.Length];
wp.CopyTo(objv1, 0);

simconnect.SetDataOnSimObject(DEFINITIONS.Extra300SWaypoints, Extra300SID, 0, objv1);

}

I tried the freeze alt/lat/long, send the above waypoint, then unfreeze it, still get exception 19 (I dont think thats the problem).

I think my methodology of updating new waypoints is wrong...but out of ideas now...

This is for school project. Help will be much appreciated.

Sincerely,

Sam

 

[caKus]

Hi Sam,

I have been using intensively this method and it works alright.

Exception 19 is a data size error. So, I suspect a problem with the SimConnect_AddToDataDefinition command.

Patrick.

 

[TOWSIM]

I even use this method to control AI aircraft interactively. The only difference to my solution is, that I set the SIMCONNECT_DATA_WAYPOINT. percentThrottle explicitely to zero and I take care, that the SimConnect_SetDataOnSimObject is invoked only from the thread who opened the connection. No idea whether this little difference could explain your effect.
Regards,
Mike