摘要：The monitoring of power consumption has become of a great interest in recent years as well as the innovative technologies available to realize Wireless Sensor Networks (WSNs) have experienced a great growth. While smart metering technologies for electric energy are already established, as sensors power supply comes directly from power lines, WSN nodes for gas metering should necessarily be equipped with long life batteries. The presented work describes a new prototypal low cost WSN designed ad hoc for gas smart metering. The network has a star topology: each sensor node can be completely integrated with standard reed relay gas meter, and it is capable to measure the gas consumption. The information is sent to the central node (the Access Point, AP) through an RF links. The sensor nodes have been designed with custom electronics and a proprietary firmware, in order to work with a common 3.6 V lithium battery which is able to ensure a life period of about 10 years for each node. Only the AP must be connected directly to electric power. The AP is connected through the RS-232 interface to a control embedded PC equipped with a LAMP (Linux, Apache, MySQL, PHP) framework: it stores all the information coming from each node in a coherent database and allows authorized users to check the network status using a web interface. The WSN is self-learning and it is capable to detect new nodes joining the network without altering the normal operative flow. Moreover e-mail and SMS alerts can be activated to alert if a node is disconnected from the network or some problems occur. A first prototype of the WSN has been already tested achieving good results.

摘要：Photovoltaic (PV) systems have attracted increasing attention in last years as well as Wireless Sensor Networks (WSNs), which have been used in many application fields. In PV plants, especially in ground installations, a lot of thefts and damages occur due to the still high cost of the modules. A new experimental WSN ad-hoc has been designed to be an anti-theft alarm system. Each node of the network is directly installed under each PV string and it is equipped with an accelerometer sensor capable to detect a minimum displacement of the panel from its steady position. The WSN presents a star topology: a master node cyclically interrogates the slave nodes through RF link. It collects all the nodes responses and communicates though a RS-232 interface with a control PC checking the network status. When a slave node detects an alarm, continuous messages are sent to the control PC which turns on all the alarm signaling systems. The control PC is equipped with an open source operative system and software and provides for SMS, e-mail and sound-light signaling in case of alarm. It also communicates with a remote server where all the WSN information is stored. A first low cost experimental WSN has been already installed and it is working properly.