Hello Team (Hello Vlad),

I assigned to the pin 30 the multiplexer where I connected for a test, two 3-pos toggle switch (Where central is ground). Four pin are in use 0+1n and 2+1n. 

With my surprise, trying the first switch, independently if I was moving it up or down, the "virtual switch" in my b737Zibo, was moving always up... connecting ground to c2 (which was assigned to the other switch) the first switch is went down....there was a strange overlap...

Obviously I double checked all the electrical connections, I tried to remove the ground to EN, connect to it another ground, Double checked the data.cfg, tried to reconfigured....moreover... the "funny" thing is if try some different pin (SIG) using for eg, Pin 13 or 18 on my Arduino Mega during the same configuration... the multiplexer doesn't works at all!

Only with PIN 30.  :-\ 

I also tried to connect the same 3Pos toggle switch direcly on the arduino mega an it works fine. I assume the problem can be my multiplexer and I'm going to replace it.

However,can you confirm I'm doing everything correctly?

Thank you so much for your best support and work!!


in Wiring, Powering by

1 Answer

0 votes


If you have connected your 3-pos switch correctly as in the picture (red switch) -   you need to check your wires again:

It seems like you have swapped two lines S0, S1 and address line S0 has no contact at all.

>>.."remove the ground to EN, connect to it another ground,.."<<

There is no "another" ground, there is only one GND bus wire.

>>.."Only with PIN 30..."<<

Any pin should work, there is no difference between them all. Only avoid to use pin #13 as input.


Ha, ha! Pin #13 is to be avoided! Didn't know that! I use two input multiplexers connected to pins 12 and 13! No wonder I was experiencing issues with the one connected to pin 13! I wonder what's special with pin 13? Glad I read this post. Thanks Vlad. JJ
Hi Vlad! Thank you for your answer! I replaced the mutliplexer with a new one and now everything is working. Thank you also for your useful hints!