I am considering doing a project that involves a machine that can accept credit card payment automatically from customers. Think of it as a vending machine, that accept credit card.
I want to out-source the credit card part and just buy a terminal that my machine can interact with. Problem is that I have no idea how this interaction works?
I have seen that in stores, the cash register interact with the credit card terminal when the cashier "sends" the transaction amount to the terminal. Also when the transaction is done, the terminal sends some kind of acknowledge back to the cash register, so that it can log it for sales reports.
It is the same kind of interaction I want my machine to do. Question is which buses and software protocols credit card terminals use (to interact with cash registers for example)? Is there a standard? Or is it different from manufacture to manufacture?