Arduino Annunciators  for  M$  FSX


                                  Using the  ARDUINO  UNO  or  MEGA  Card   


          This project will only work using “Link2fs_Multi” (v5c upwards)



Annunciator Panel + Gear + trim  (or something else)


Where to start ,,,,

One of the confusing stages of interfacing to FSX is “where to start” ,, well that’s easy.

Here is an easy project to get you going that will give you,,,

1/. Gear up and down control. (toggle switch)

2/. Indication of gear position and “in transit”. (3 greens for gear down,, 3 red’s for gear in transition)

3/. Buttons for adjusting the trim up and down. (You can change this to something else if you want)

4/. Buttons for adjusting the flaps up and down.  (You can change this to something else if you want)

5/. Alarms for 6 various things along with a “cancel” button that sets the active alarms into flashing mode.

All this is done thru Simconnect and NOT via keyboard manipulation.


First you need ,,,

An Arduino Uno or Mega card

3  Green LED’s  (I used the 10mm ones but any size will do)

9  Red LED’s   (as above)

12  resistors to suit the LED’s (If in doubt, use 220 ohm)

1  toggle switch for the gear. (single pole, single throw)

5  Momentary push button switch’s.  (Normally open type)

1  box or a wee panel to set this all up on.


If you have a UNO card ,,,,

Wire up your bits and pieces as per this,,,





































Or ,, if you have a MEGA card ,,,,

Wire up your bits and pieces as per this,,,







































In the download there are better pictures so you can zoom into the detail while you build it.

There is nothing complicated about it ,,, just do one thing at a time and all will be well.

In the case of the Mega ,, you only need to put the switchs and LED’s onto pins 2 to 19. (Forget the rest)


You can download this project here ,,,,,

It contains the INO’s for the Uno and Mega, and a copy of this webpage.

These INO’s were compiled using Arduino’s IDE version 1.1


Next ,,,  load the appropriate INO (Uno or Mega) file into your Arduino ,, if you don’t know how to do that then read,,,,  ( An  INO and a PDE are the same thing ,, it’s the code that gets put into the Arduino)


Next, download my “Link2fs_Multi” program ,,,,

(I haven’t included it with this download as I am continually updating the “Multi” at the moment.)

It is NOT an “install” but a stand-alone program ,,, you make a folder and just unzip the “Multi” into that new folder.

Ignore all the “Demo” INO’s etc that came with the Multi” ,, all you need is the “Link2fs_Multi.exe” program.

Start “Link2fs_Multi” and check in “Extractions” that it is receiving data from FSX. (FSX needs to be running !!  )

If it don’t run at all then you’ve done something wrong OR you need to install the “.Net” framework into your computer (Minimum, framework 2)

or fiddle your UAC settings or  right click on it and “run as administrator:” etc etc ,, your on your own here I’m afraid.


Have the Arduino connected to the computer.

I used the BARON for all my setting up so until you get used to what is happening and understand how to change the parameters ,, use the BARON.


OK lets set all the ‘Link2fs_Multi’ settings ,,,,

In “SimConnect Extractions(2)” tick ,,

?Y (Gear position simple)


In “Annunciators” tick ,,

/B1 (Overspeed flaps @ 140)      (Set the actual figure to suit the plane later)

/C1 (Overspeed Gear @ 160)     (Set the actual figure to suit the plane later)

/D1 (Overspeed Frame @ 180)   (Set the actual figure to suit the plane later)

/E1 (Airspeed  Stall @ 80)          (Set the actual figure to suit the plane later)

/H1 (Total Fuel under 5%)


Make sure nothing else on any of the other pages are ticked ,, then hit the SAVE button.

Now go back to the “Communications Settings” page and connect to your Arduino.

If you’ve done everything properly ,,, it should now be working ,, hit SAVE again.

You should see data going “to” the card and when you press (say) the trim button, you will see data coming back “from” the card.

The “cancel” (pulse) button does NOT send anything back to the Multi.

Happy testing and fiddling.


If things DON’T work then check everything you have done ,,, this worked for me and what I’ve posted here works fine in my setup.

I don’t offer any help with INO’s ,, your on your own on that one.


This INO is not really a “Starter” INO for some-one to learn from ,,, it got somewhat messy because of the flashing light thing.

There are plenty of starter files included with the Multi download but if that is too much then go back to my site and download the older “InOut”

program and learn basic INO programming with it or play with the Arduino using Arduino’s own samples.



Hint No.1,,,

I didn’t use fancy plugs etc ,,,  just basically plugged the Resistor required straight into the sockets. (After trimming)

If your resistors are “fatter” than the ones I used then just bend the end that plugs in, into a tight step to one side. (Don’t go out wider than the body of the resistor though as it could short to the one beside it.)

Putting the Arduino into a small high-walled box helps this physically or, once its all together, hot-glue all the resistors together to make a “plug”.

Sooo ,,,,




































Yes the pictures show a mega card.


Hint No.2

When things get a bit “bigger” there isn’t enough GND pins for all the cables coming from different directions.

To overcome this I use a socket from an old computer cable, short them altogether and plug that into a GND socket on the board. You can see this in the bottom right picture, in the bottom right corner of the box.  I used a cable tie to “strap it” to the box. Or you could use hot glue.

NOW I have heaps of GND sockets.


Hint No.3

For the end of the wires that didn’t have a resistor, I used the same method but used the off-cuts from the previous resistors and covered the solder join with heat-shrink to insulate them from one-an-other.




The same as all my other stuff,,,

Use at your own risk.

There is NO support.

This is what I done ,,, It worked for me.

If it don’t work for you, then go and try something else.




Dated   12 July 2013


Flowchart: Alternate Process:  Back to the simulator main page.