Remote Automatic Doorman via the Internet

Abstract

This paper describes a system designed to take actions o a remote building using an old PC with Internet connection.It is based on a card that uses several relays to close independent circuits.The card is connected to the PC parallel port that receives the orders from Internet.The system has been applied to open the door of an office from another building, just across the street, without using any cable. The delay since clicking the mouse and the door opening is less than 1 second, so the system is very fast and convenient, compared with similar systems based o telephone calls. The automatic-doorman-PC is an old Pentium with just 16 MB of memory running Linux operating system.