Possible GTN650 integration?

Black Square

I almost don't want to give away the secret... This is how I implemented the GNS "takeover" of the autopilot. There are actually two GNS's in the airplane. One is passive, and the other takes control of the autopilot when it's enabled. This is because Working Title has not implemented some of the hot-swapping features that other GPS developers have, which would allow me to toggle their autopilot features on and off live. Come to think of it, you're going to have a tough time getting the GTN to do more than appear in the cockpit for reference, if you also want it to control the autopilot. Still very possible, but you will need to make some code modifications that I can help you with.

jmarkows

@Black-Square aha! I was wondering how you had worked around the WT hot swapping issue since we were dealing with it with the Caravan (in my case) in the last year or so.

Don't worry, unlike learning how a magic trick is performed, here the wonder and marvel still remain

Rhinozherous

Is there a way to use the TDS GTN in standalone mode with the Starship? I tried it (having it open in a window on a second monitor) and it seems it messed up the flightplan and autopilot (for the autopilot only the assignments from the manual where used). After takeoff it was not following the plan (GNS was set as source) and autopilot did all kinds of crazy stuff.

@Black-Square Would it be more "easy" to somehow implement the use of standalone mode for GTNs? I am fine if this is not possible at all, I am just curious!

Rhinozherous

As I also have the PMS50 GTN installed I tried this one. it seems the PMS50 can directly modify the Starships CDU flightplan - I am currently testing....

Rhinozherous

It works like a charm with the PMS50 GTN - I use it as a pop out on my second monitor and it is writing directly into the cdu.

Dingle

@Rhinozherous what do you mean as a pop out? Just open it from the top menu and use it?

Rhinozherous

@Dingle said in Possible GTN650 integration?:

@Rhinozherous what do you mean as a pop out? Just open it from the top menu and use it?

This works at least in MSFS2020, i did not trie it in 24 so far:
Open it from the top menu, minimize it (the arrow symbol in the top left), now you can drag it onto another monitor and resize it to your liking.

Andydigital

It does work in 2024, I use it all the time with the Starship

Dingle

Thanks, I will give it a try, thanks!

MarkS

@Black-Square thus far I've only been able to get the GTN650 to replace the 430 in the N2000A plain livery, which is the panel folder without a tail number, and then only after configuring a hardware switch in AAO to turn on the avionics master (I don't think you're using this switch, but the GTN unit needs it). I've had a series of, shall we say, "adventures" with the other liveries, depending on which method I use. If I put everything in an external mod (like you're supposed to), the GNS430 continues to show up in the non-plain liveries. If I make the changes directly inside the aircraft folder (bad bad bad), the GTN650 appears but cycles on and off at short irregular intervals. I suspect this latter item might have something to do with the dual-GPS implementation. The GTN replacement method is one I've used on over 70 other aircraft in both 2020 and 2024, including other Black Square offerings, so I'm at something of a loss to understand why this plane is so different.

Black Square

Sorry to keep this short for now, but I can't think of any reason the other panel.cfg's would behave any differently, unless your mod is not being loaded into the virtual file system at all. I don't know if you're familiar with the VFS inspector in Developer Mode, but that's where I would be looking. Once you located the panel.cfg in the right Starship sub-folder, hover-over to see where it's being pulled from. If it doesn't have the name of your mod in the file string, then it's not being ingested.

MarkS

Success! Thanks for the VFS tip @Black-Square, it helped set me on the right track. I now have the GTN650 working in all liveries in both 2020 and 2024. The GTN also appears to be able to control the autopilot without any significant issues.

Two minor issues:

The GTN powers on with the main battery instead of the copilot avionics switch; this is because the GTN needs the 'standard' avionics switch for power, which the stock Starship does not appear to use, so the switch is forced on in the apron.flt and hangar.flt files.
Any custom settings you make to the GTN (display fields, etc) will need to be made twice, because there are two GPS units defined depending on whether the GPS is enabled for autopilot control.

I'm going to let this simmer for a day or so and get a few more testers' eyes on it before putting it up on fsto.

Dingle

Wow, nice. I would be happy to test it aswell.

patchadams502003

Oh nice! I’m willing to upgrade my starship to the GTN650

Black Square

You can fix the electrical problem by adding the following lines of code to Starship_Interior.XML, after 0 (>L:var_ManualExtensionHandleFailure, bool)

@GpsCircuit(&gt;L:TDSGTNXI650U1_ElectricalCircuit, number)
@GpsCircuit(&gt;L:TDSGTNXI650U2_ElectricalCircuit, number)

HOWEVER: I still suspect the unit will not know when to turn on and off, or when to control the autopilot without some more code changes. You're welcome to have fun for the time being, but please be aware that you are changing things that were never meant to be changed in Starship if you have crazy autopilot problems.

MarkS

@Black-Square the lvars you provided look to be for the TDS GTN unit, I'm using the PMS50 GTN. Since the PMS requires AVIONICS MASTER SWITCH for power, it seems reasonable to have that switch track the value of var_AvionicsCoPilotSwitch so that it powers with the copilot avionics like the GNS does, something like this (RPN is not my strongest language) in the interior xml:

(L:var_AvionicsCoPilotSwitch, bool) (A:AVIONICS MASTER SWITCH, bool) != if{ 
   (L:var_AvionicsCoPilotSwitch, bool) (&gt;K:AVIONICS_MASTER_SET)
}

I've done several flights to test the interaction with the autopilot. No issues so far with power or switching between FMS and GNS. Is there a particular scenario where you think things could go sideways?

Black Square

Ah. You should be able to solve that too by adding these sections to all the panel.XML's. I might not have that 100% correct, but give it a try.

	<Instrument>
		<Name>GTN650_INT</Name>
		<ComIndex>1</ComIndex>
		<NavIndex>1</NavIndex>
		<Electric>
			<Simvar name="CIRCUIT ON:135" unit="Boolean"/>
		</Electric>
	</Instrument>

	<Instrument>
		<Name>GTN650_INT</Name>
		<ComIndex>2</ComIndex>
		<NavIndex>2</NavIndex>
		<Electric>
			<Simvar name="CIRCUIT ON:135" unit="Boolean"/>
		</Electric>
	</Instrument>

I will also try to fix the "avionics switch" problem. I've fixed that in other aircraft, but I guess it never made it to Starship. Often, hardware will still fight with those events.

MarkS

I added those sections to the panel.xmls but then something was preventing livery selection (weird), so I took them out. On the plus side, the code snippet to have the avionics master track the copilot avionics switch works, so the GTN power behaves the same as the GNS.

Black Square

I'll have the avionics switch fixed for you in the next update too. Did you rebuild the Layout.json after making those changes, if you're testing in MSFS 2024? That might have caused the livery problem.

Dingle

Did you observe a loss of the flight plan when the Power goes off and on aswell as in the GNS430?