MobiFlight Community Support

Good evening,

I have been setting up a 12 position rotary switch on 5 positions. (This is for a ProsimParts Boeing 737 Transponder panel mode select switch)

As I rotate the switch it detects the contact and reads it as "release" and when rotated further it reads the disconnection as a "Press", I am thinking it may be the PCB that the switch is connected to. I had the switch apart and shorted the pins with a jumper wire and still the same issue.

I have connected one of my own 12 position switches and it works correctly.

For now I have resolved the problem by setting the switch to action on "Release". I was wondering if anyone else has experienced this sort of behaviour with a rotary switch....

Regards to everyone.

Steve

Hi

Without see the shematic of the PCB i can not give you a confirmed statement.

On first view the PCB is for inverted Logic To MF.... it not set Pins to GRD.... it set Pins to 5V !

If you have a multimeter scan tool you can check it yourself....
I expect the mid Pin (common) is 5V ..... For MF usage it should be GRD.

Thank you it looks like you are correct !!

So solution can be easy or difficult....

Way 1.... Use inverted Logic in MF.... As you do work with the release.

Way 2... Check the wire (pcb line) logic of the board.
IN theory also all Buttons or latching switches work inverted.

If there is a own "common" Circuit for Inputs you pretty sure wire it as written in the manuals to 5V....
Simply Change it to GRD and all should be fine.

But take Care..... If the Board use this 5V also for Outputs like LED you can get in trouble.

For example on Hispapanels PCB´s there is a seperate Common Circuit for IN and Out. The In is set to GRD ( as expected) but the OUT is set to 5V.
Here we have to invert all LED outputs.... it light if Value in MF is "0" and it not light if value is "1".
BUT
Also there we can easy rework this.... We simply turn LED´s by 180° and we set GRD instead of 5V to the common Pin.


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At the End.... this is no issue itself.
Pretty sure the PCB was designed for a different Software. MF go the know way.... Other Software go a inverted way.
So hardly eyplaned.... The error is yours in case you use a Hardware with a software that it was not planned for.