I need arduino developer

i want to make a new project wih arduino uno board if it possible the project that i have on my mind.
write down a code for:
i have 8 analog coin acceptors ,from each coin acceptor i can take2 wires from the relay a)5v b)Gnd
so i want to read the 5v and when goes 0v (coin insert) print the change on serial
example : pin1 0.50e or pin2 2e etc
(with the interupts)
cause i want to know from which pin it come and the prefixed value of the pin