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Programming interface to associate Switch Devices to FSX GPS


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System Summary: Desktop PC running Windows 7- 64 bit, S.P.1, FSX-SE, FSUIPC4 Registered


My proposed project is like many others I have looked at on the 'net. I wish to free myself of the mouse when using the various GPS panels in FSX stock aircraft. Many projects I have seen both D.I.Y and commercially available claim to do the job (I am referring to the ones using the popular USB button/switch circuit boards.) I find info. on the 'net that seems to be contradictory. As recently as 2020 dated posts elsewhere people have said this is not possible. I have read that the GPS panel buttons are only clickable regions on the panel that do not have (for lack of a better term) command codes. Of course I understand there must be some sort of command sent to FSX to affect the needed function.


I have been searching endlessly on the 'net for the programmable numeric codes or "handles" that I can use within my licensed FSUIPC4 to which I can associate a joystick and button with each action on the GPS panel. So far the only choices I can see are the FSUIPC "Buttons" tab drop-down list box which offers up some 20 or so GPS related commands. This list doesn't appear to represent all the possibilities on the 2 GPS types of panels offered in the stock aircraft in FSX. Please correct me if I'm wrong.


I have observed that the "Button Board" products for D.I.Y. sim builders have software associated with them that allows them to function in the sim. but as of yet I do not understand how those physical devices (buttons, encoders, etc.) get mapped over to all the button functions of the GPS panel since a mouse click on a panel image is not detected by FSUIPC like a Keyboard and Joystick buttons are.


I am reaching out to successful D.I.Y. builders of such a switch bank that operates the GPS panels in FSX. Would someone confirm if there is a solution to this problem and what the key concepts are here. Lacking that, could you direct me to an explanation on some website or forum? If this message looks familiar I have posted it on other sim forums because there seems to be limited activity on other sites I have searched.

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Yes, this is entirely possible with FSUIPC (or indeed, without). You can find the appropriate event ids in the SDK documentation here. I have done this for a complete implementation of the GNS530 in my Twin Otter cockpit, which is essentially the default FSX GPS with a veneer to make it look like a GNS530. I used Leo Bodnar BBI32 boards, which appear to FSX as collections of simple buttons, with up/down actions. I also used LINDA to make the programming easier. LINDA makes Lua programming more accessible, although for the GPS you do't really need Lua.


There are lots of videos on my YT channel about programming the GPS, including

. You can see the GPS in action in various videos, including
(start from about 3:10)You can find LINDA code for the GPS at my forum (linked from the YT page), although you shouldn't really need it.




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It may not completely address what you are looking for, but I use HID Macros and a standalone keypad to control my default GPS. No rotaries or anything, but it works pretty well. It wouldn't fit if with a DIY panel, but it serves me.

Ernest Pergrem

System: i7-13700K, Gigabyte Z790 UD AX, 32GB RAM, GeForce GTX 1080 FTW Gaming, Windows 11 Pro 64-bit, MSFS 2020, FSX, Thrustmaster T.16000M Joystick, Cessna Pedals, Saitek Trim Wheel, Switch Panel, and Multi Panel

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