Designing a Low Cost Electronic Devices Switching System Controlled by Short Message Service

This paper explains how a Short Message is used as a command to remotely control a switching system. There is a great demand for applications that can remotely control electrical or electronic devices. Over the last decade, the implementation of this concept has been attempted by using the Internet and through power-line modems. However, these solutions are not only complex but also require a physical connection to access those devices. A simple, cost-effective solution is proposed here, by which devices as mentioned above can be controlled remotely while the user is anywhere across the globe. Short Message Service (SMS) is a mechanism of delivery of short messages over mobile networks that are widely spread all over the world. A mobile phone which is connected to a PC is used to receive commands from the owner. After receiving the text commands, the received data will be analyzed by the PC program and then PC will set the status of its parallel port data pins to high or low. The switches of all the controllable devices are connected to the PC parallel port. Therefore, by sending appropriate data via SMS, the devices can be switched ON/OFF remotely.