CERERE (Crop and Environmental wiREless monitoRing System) is a complete system for agricultural and environmental control using a Wireless Sensor Network.
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. However Squidbee motes are quite energy consuming and not suitable for battery-powered application. Moreover, nodes use 802.15.4 RF modules but lack a complete network stack; therefore the setup and the management of a Squidbee-based WSN is quite complex and time-consuming.
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 an open (and cheap) gateway – actually a Koala nano PC running Linux and SQLite.
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.
A short presentation by Filippo De Stefani, including many screenshots and additional information, is available here.
All the software needed to setup a working CERERE network is freely available here.
Source code written by Filippo De Stefani is released under the GNU GPL License. SQLite is in the Public Domain. Techfell protocol and uSQLite have been originally written by Roger Irwin and they are in the Public Domain.