Wireless Sensor Networks For Watershed Assessment
Emerging Technologies
Implementing a large scale sensor deployment for watershed 
assessment has previously been limited by the high cost of the datalogging and communication infrastructure.
The Christina River Basin Critical Zone Observatory (CRB-CZO) is overcoming the obstacles to large near-real-time data collection networks by using Arduino, an open source electronics platform, in combination with XBee ZigBee wireless radio modules.
The open-source nature of Arduino means the cost is extremely low compared to similar commercial electronics options.
By significantly decreasing the cost of the datalogging and communication hardware, resources can be focused on installing more sensors for greater spatial coverage.
Researchers, students, and individuals can easily build and deploy inexpensive dataloggers without the need for electronics experience, complicated software, or specialized tools. Dozens of low cost boards allow even novice users to build devices using boards that connect in a modular framework.
Benefits of Open-Source Datalogger Hardware
Low Cost: For around $150, we can replicate 
the capabilities of a $3000 wireless commercial datalogger system.
Ease of use: The Arduino electronics prototyping platform was initially designed "for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments." As such, the Arduino family of electronics hardware is easy to snap together and program; yet it is also capable of nearly any task we might imagine.
Support: The large user community provides support as well as constant innovation and development of new hardware and applications
Reliability: Self-healing mesh wireless networks route the radio signal from the nodes to the base station using the most efficient route. Each node also has a removable memory card to store a backup of the sensor data
Compatibility: Commercial dataloggers can join an Arduino mesh network by simply connecting an Xbee radio module to the logger so it can transmit the data that it usually only stores on its internal memory
Our Preliminary Results
We believe that using open-source electronics hardware for watershed instrumentation will transform our ability to deploy sensors, field instruments, and other electronic "eyes and ears" to unprecedented levels. High quality commercial sensors are relatively inexpensive and widely available. Easy customization of the Arduino node interface hardware and software means virtually any sensor can be used.
Documentation Note
As we finalize our electrical designs and Arduino programming code in the coming months, we will be sharing all of the documentation for our loggers and other devices so anyone can replicate and implement their own versions of our instrumentation. For more information, contact contact Steve Hicks.
Building the Networks
Datalogger nodes consist of a microprocessor board paired with a radio module, all mounted in a weatherproof enclosure along with a solar panel and rechargeable battery.
The nodes conserve battery power by sleeping most of the time, then waking periodically to take measurements from the sensors, and then transmitting their data through the mesh back to the base before going back to sleep.
In areas with no mesh network, standalone loggers with just a memory card can be used.
Custom Devices
Other custom devices such as a remote streamwater sampling system and a multi-chamber respirometer controller can be built using the same type of Arduino microprocessor boards.
|
|
Soil moisture datalogger |
|
Laboratory respirometer |
|
Portable respirometer |
Data Visualization
At the base station, the incoming live streaming data can be displayed on a computer, stored in a database, and plotted on a web page for near-real-time viewing and analysis.
The chart below shows live stream depth data from an Arduino stream gage on White Clay Creek at Stroud Water Research Center.
Live stream depth data (in centimeters) from White Clay Creek :
Links:
-
Forum for Adafruit Industries, an open-source hardware company that sells kits and parts for original, open source hardware electronics projects
Arduino Electronics Platform
The information in this page was presented at the 2011 Fall Meeting of the American Geophysical Union.
View the poster.Online Resources, Tutorials, Product
Xbee ZigBee Radio Modules
