CERERE: a WSN for Agricultural and Environmental Control
Agriculture is one of the areas most likely to benefit from the deployment of wireless sensor networks. Squidbee motes, usually equipped with temperature, humidity and light sensors, could play a role in preserving the environment by reducing water usage and providing early alerts for frost or high temperature damage. Energy consumption and dealing with an incomplete network stack (when using 802.15.4) are the goals of this project. We have developed a stack for Squidbee motes in order to make it easier the setup of a WSN with SquidBee.
Firstly, we have developed an experimental stack for Squidbee nodes: our network is auto-organizing and uses a simple reactive, hierarchical routing protocol. In addition, nodes can enter in sleep mode to save battery: we have profiled the power consumption of every component of Squidbee motes and we have identified strategies to increase energy efficiency. For example, we have been implementing a Scheduled-Rendezvous protocol to organize transmissions and synchronize sleep/wake-up cycles of nodes. We have also studied the effects of vegetation, humidity and position of nodes on the propagation and strength of XBee radio signal.
Then we have developed a multi-tier, interactive Web application to monitor the status of the wireless sensor network. Our system is similar to Meshlium Manager System in some aspect: it allows to manage the WSN just using a web browser. Moreover, data are stored into a lightweight relational DBMS running on the gateway, a Koala nano PC running Linux. Instantaneous sensed data can be visualized on a map using a mashup (based on Google Maps) or a GIS application. Moreover, the evolution of measured values can be plotted on-line using an AJAX script; in addition, data can be exported to a spreadsheet or to an Extended Environments Markup Language (EEML) properly-formatted file, a standard for sharing sensor data between remote responsive environments, both physical and virtual.
All the software is freely available and is released under the GNU GPL License.
This work will be presented at INPUT08, 5th National Conference on IT for Territorial and Urban Pianification, Lecco, Italy, 4-6 March 2009
A short presentation, including many screenshots, and the full thesis (in Italian) by Filippo De Stefani can be downloaded from:
Presentation in English:
Article submitted by Prof. Paolo Gamba, Ing. Emanuele Goldoni, Filippo De Stefani (University of Pavia / TLC and Electronics Lab).