Using limit switch

[TomGeorge]

Hi,
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@oldgee

Thanks for your reply. I tried to connect the limit switch COM to ground and NO to 5V and A4.

That will short your power supply out when the NO becomes closed.
You need;

A4 to COM
GND to NO
no connection to NC.

The pull_ups will provide the 5V.
Your A4 will be at 5V and go to GND when the limit switch is closed.

Tom....