Switch and resistance

[nicolamassarenti]

Hi all,
i am using Arduino Mega 2560, and i have a switching pcb. I will use 5V from Arduino, and i need a resistance beetween vcc and switches.
How much has to be the resistance?

Thanks in advance.
Nicola

[pwillard]

A schematic will help here...

...having us trace a pcb for you to figure out what you intended it to do is needed before any advice is given.  Maybe someone else is willing to trace your PCB.

[nicolamassarenti]

I have two boards. The right board is the "master" and the left board sends to the right signals (i use flat cable). From the right board i send to Arduino signals. I'm using the Mux Shield to had multiple digital input tools.

I attached two photos of my pcb project. I hope my circuit goes well  :~

dx.jpg is the right board
sx.jpg is the left board