XBee-Enabled Sensors Monitor Harsh Environments
Sensor technology research and development is important for monitoring the environment around us, ranging from prevention of forest fires and floods to detecting and monitoring contamination levels in cities. The research and development team at Libelium in Zaragoza, Spain, is dedicated to developing hardware for the implementation of wireless sensor networks, mesh networks and communication protocols.
Libelium needed radio frequency modules to guarantee accurate transmission of information from sensors placed in isolated or difficult-to-access areas. To enable Libelium to develop its sensor devices, the company needed to source a wireless networking provider that offered both long-range links and the interconnection of wireless networks of different frequencies.
Using XBee modules from Digi as the main communication radios, Libelium developed the Waspmote – a low-power wireless sensor capture, geo-localisation and communication device with high transmission power. Based on a modular architecture, Waspmote is able to detect a variety of parameters such as humidity, temperature, CO2 emissions, heartbeats and vibrations. Waspmote can be used in numerous industries including agriculture, environmental, logistics and security.
"Our objective is to detect and store critical values and send these values to a data processing centre for analysis or send emergency alarms. Take the agricultural industry as an example. Waspmote sends a message through the ZigBee network when the sensors detect that the optimal level is reached in soil humidity. This contributes greatly towards efficient water management," explains David Gascón, Libelium's CTO. "It is therefore vital for us to deploy modules built to operate reliably under a wide range of conditions."
The Digi modules satisfy the unique needs of Libelium, providing low-cost and low-power wireless sensor networks. Designed to operate in harsh environments, the modules allow Libelium to network-enable sensor devices so that they can be monitored and controlled remotely. Libelium currently deploys the XBee and XBee-PRO 802.15.4 and DigiMesh® modules; XBee ZB modules; XBee XSC (900 Mhz) and XBee 868.
"The Digi modules operate from 868 to 900 MHz and 2.4 GHz," says Gascón. "This is an invaluable advantage to us, as it means that we are able to choose the model we need and to reach international markets with just one plug. Likewise, it is easy for us to change protocol (802.15.4 or ZigBee) and transmission power (1 mW or 100 mW)."
Waspmote is able to achieve long-range links of 7 km / 2.4 GHz, 24 km / 900 MHz and 40 km / 868 MHz, making it possible to monitor virtually any installation.
"The long-range links are fundamental when monitoring delicate natural environments," explains Gascón. "Infrared or ultraviolet sensors are used to detect flames, heat and gases that help identify the molecules of chemical compounds (CO and CO2) generated during combustion. A Waspmote sensor device can help to detect and prevent forest fires." Gascón continues, "Another example application is in the logistics field. Thanks to the Digi technology, shipping container conditions such as irregular temperatures and humidity levels, and whether the products have been contaminated or suffered an impact during transportation can be detected by Waspmote. Our technology allows this information to be transmitted wirelessly."
Pleased with the partnership, Gascón concludes, "Digi has an outstanding reputation for reliable products and they have met all of our project requirements for Waspmote. We will certainly continue to use Digi products for future developments at Libelium."