Abstract—This paper describes the project and development of a very low-cost and small electronic prototype, especially designed for monitoring and controlling existing home automation alarm systems (intruder, smoke, gas, flood, etc.), via TCP/IP, with a typical web browser. Its use will allow home owners to be immediately alerted and aware when an alarm event occurs, and being also able to interact with their home automation alarm system, disarming, arming and watching event alerts, with a personal wireless Wi-Fi PDA or smartphone logged on to a dedicated predefined web page, and using also a PC or Laptop. Keywords—Alarm Systems, Home Automation, Web-Server, TCP/IP. I. INTRODUCTION HERE are nowadays in the market many different types of home automation systems. Although several popular integrated systems like X10, EIB (European Installation Bus), Echelon Lonworks, and National Instruments LabVIEW modules, already bring along the possibility to add internet servers for distance remote web monitoring/control and for alarm notification, these are yet still quite expensive and are not usually full compatible with previous home automation models. The mail goal for this project was to build a very low-cost electronic prototype, with the use of an embedded standard micro web-server, with built-in IP connectivity, to allow receiving and sending digital commands, via TCP/IP [1], for all existing alarm and notification home automation models, and without the need to have a dedicated server PC or even special software. II. HARDWARE IMPLEMENTATION A. The Micro Web-Server The low-cost Modtronix SBC45EC board [2] was used to implement the micro web-server. It contains a PIC18F452 microcontroller [3] and a 24LC1025 non-volatile EEPROM Manuscript received December 31, 2007. This work was supported by Escola Superior de Tecnologia de Setúbal (ESTSetúbal), Portugal. Helder Adão is a final year BSc Electronics and Computers Student at Escola Superior de Tecnologia de Setúbal, Professor Rui Antunes and Assistant Frederico Grilo are with the Electrical Engineering Department at Escola Superior de Tecnologia de Setúbal (Setúbal Polytechnic Institute), Rua Vale de Chaves, Estefanilha, 2910-761 Setúbal, Portugal (phone: 351-265- 790000; fax: 351-265-721869; e-mail: rui.antunes@estsetubal.ips.pt , fgrilo@est.ips.pt). that can store up to 128Kbyte of data (net configuration, username and password for login, I/O values, and for the web pages that will be loaded and presented [4]). Fig. 1 Modtronix SBC45EC board It has also an Ethernet 10BaseT interface, allowing the connection to an Ethernet line. Sample source code for programming is also available at the web site: http://www.modtronix.com/products/sbc45ec/ . B. An Implementation for Intruder Alarm Systems It was used a DSC PowerSeries [5] intruder alarm control panel to test the web-control module for alarm monitoring, notification and control. The basic electrical signals used are: The BELL signal is an output from the alarm control panel. It is used for triggering sounder devices. The STROBE signal is another output from the alarm control panel that will enable the flash lamps from the external sounder. VBAT and GND are the power source terminals for the alarm control and the external sounder. Power is +12V. TR (“Tamper Return”) input is the external sounder output signal, and it is used to inform of an opened sounder cover tamper condition. In all hardwired commercial alarm systems each protected zone is made with a closed loop circuit, where a fixed controlled current flows [6]. The first protected zones are usually door entry zones, for manual or remote entry and exit pre-time arming and disarming. Several intruder alarm configurations are available. Usually are called NC, NO, EOLR, DEOLR (or 2-EOLR), and 3-EOLR loop circuits. Web-Based Control & Notification for Home Automation Alarm Systems Helder Adão, Rui Antunes, and Frederico Grilo T TABLE I ELECTRICAL SIGNALS OF AN INTRUDER ALARM SYSTEM Signal Function Source Enabled BELL sounder bell output +12V" 0V STR sounder strobe output +12V" 0V VBAT power (+12V) power All GND ground (0V) power All TR sounder tamper return input 0VOpen International Journal of Electrical and Computer Engineering 3:9 2008 586