I'm currently having a project and I have a question regarding the output pins. Can I use (3) three Arduino Nano to parallel with the Switch that I have built. Below is on how to picture out my question and the wiring diagram.
(deleted)
OP image.
How to post images so we don't have to download them and everyone can see them.
How to post an image.
Another page on posting images.
220 Ohm pull down seems like a very low value pulldown resistor. Usual minimum is 1K or so for long wires to the switch (strong pulldown). 4.7K to 10K is more normal.
You do not show a Vcc and grounds to the breadboard. Are we to assume that connection? Because the switch will not work without those connections.
Can I parallel (3) three Arduino Nano output pin 7 with Toggle Switch
You asked about connection to an output pin. No. You can't connect 1 switch to an output pin, let alone to 3 output pins. If you really meant input pin that's ok.