Induction sensors

I have an induction sensor I wish to use to sense the movement of a machine part (metal)
I am putting the sensor wire into A0
What's the best code method to say turn a LED High when the sensor detects metal.
Many thanks

Post a link to the product page or data sheet for the sensor.

There are several sorts of inductive proximity sensor, principally NPN or PNP open collector
outputs, 5V logic outputs, current loop outputs even - if you want an answer better than
"use the correct interface technique for your sensor", you have to give us all the details on your