MobiFlight Community Support

Hi guys,
I have been experimenting with normal 2 position switches that use 1 pin and find it usually works quite reliably with the PMDG 737 NG for MSFS 2020. I have recently acquired an APU start switch which has 3 positions possible. Off/On/ and a momentary spring loaded Start position.

It will use 3 pins or only 2 ? That is my first question.
How would the input configuration screen look like, so it is possible to define the 3 positions the switch is capable of. ?

Many thanks in advance for any help offered.

Best Regards Eddie

Hi Eddie,

It all depends on what type of switch you are using, but for this i use a toggle switch which is configured as on/off/(on) (where the (on) is the momentary one)

Here you will use 3 pins, and configure it as 2 separate buttons in Mobiflight. You will have a button 'APU Off' and a button 'APU Start'.

Configuration for the APU Off button:





Configuration for the APU Start button:



This one doesn't have anything for the 'On release' action, that's just left blank.

That ought to do it. If you can't get it to work, please specifiy in more detail what switch you are using for it.

I'm using a real B737 APU switch which has the 3 positions possible, so using your 2 switch analogy should work great. It makes sense. I'll let you know how I get on with it.
Many thanks.

So, I should be able to configure the ON position and output an LED to it too.

Hey Guys.

Whatever the Solution of Aeolus work here.... This is not correct at the end.

Basic Idea:

Electrical ist no mater if a Switch is latching "ON" or Momentary "(ON)" .
This is just a functional (physical) fact... Electrical both are the same.... ON if PRESS.... OFF if RELEASE.

For a 3 Position switch we finally choose between 2 differen versions.....

1. a ON-ON-ON switch ( 3 Controlled Pins)
2. a ON-OFF-ON switch (2 controleld Pins)

The first one is pretty easy.... We create in Mobiflight 3 Devices .... all three are Buttons.... E.g, Button 1 (UP) on Pin 10 ... Button 2 (MID) on Pin 11 and Button 3 (DWN) on pin 12.
Each button got only a ON PRESS Action and send the needed command for the current position. ( So you need 3 Input Configs here)

The Second share the Middle Position....
A On-Off-On switch means.... UP is Button 1 Press.... DWN is Button 2 Press..... MID is Relaese of BOTH!!!! Buttons.
So whatever you move the switch from UP to MID .... or from DWN to MID.... Both Releases will send the same Command for the Mid Position.

So in this Case you only need TWO Configs in MF.... But now Both of them need the Release Tab and send BOTH the Mid Command there.


Summary:

This one doesn't have anything for the 'On release' action, that's just left blank.

Thats technical worng.
It work in PMDG cause the Switch move back in Sim by itself (cause its a momentary switch also in sim)
So it only work in case PMDG on this special switch do the release automaticaly
BUT
To use this logic for other 3 way switches..... its hig recommend to understand.... Both side need the Release !

hi pizman,

let me, first of all, make clear that i have much respect for the amount of time you're spending on this forum answering questions, and just as much respect for your mobiflight knowledge, however, in this case i strongly disagree with you.

Thats technical worng.
It work in PMDG cause the Switch move back in Sim by itself (cause its a momentary switch also in sim)
So it only work in case PMDG on this special switch do the release automaticaly

It is not wrong, and the reason why it's not wrong is already given by yourself. Yes, this works only in the specific cases where the switch in the sim is also a momentary switch, but the question of the topicstarter was specifically aimed at the pmdg, and the apu switch. When you set the apu switch in the pmdg to 'start' and release it, it always takes a small second for it to actually release in the simulator. I believe that if you put an 'on release' action to the start switch, it will release inmediatly when you release the switch hooked up on mobiflight, which could lead to errors like the apu not starting because the switch is released too fast.

Of course this will not be the case for other switches in other aircrafts, but the topicstarter wasn't informing about that.