How can i read High Voltages.

Hey guys,

I am working on a project for my home automation using mqtt.
My garage door has internal normally closed endstops built in.
I measured the voltage of that pin in parallel, 35Volts.
But now i don't know how to read the switch with my esp8266 or my arduino uno.

Any tips?



And if you want to be extra-safe use a [u]protection circuit[/u].