Abstract
Wireless Sensor Networks (WSNs) have become the ideal candidate to provide effective and economically viable solutions for a large variety of applications ranging from health monitoring, scientific data collection, environmental monitoring to military operations. In this paper, we present a proof-of-concept WSN to collect soil moisture content, which is one of the most fundamental data required for precision agriculture. Leveraging existing off-the-shelf hardware (MicaZ motes, MDA300CA data acquisition board, and EC-5 soil moisture sensors), the dominant open source embedded operating systems software (TinyOS 2.1.1), and MViz, we have built a prototype WSN to collect soil moisture. We present the detailed design and implementation of MDA300CA driver for TinyOS 2.1.1. Note that our architecture is general, so it is easy to integrate the driver of other sensor probes, thus collecting more types of data for different research purposes. Limited battery supply is a major concern when utilizing WSNs to build realistic applications. Therefore, we utilize solar panels and rechargeable battery to address this challenging problem. We illustrate our detailed design to package WSN nodes for outdoor development and present collected data to validate our design. Specifically, using sand soils with different water content, we demonstrate the result of our system. With enough details for researchers to understand and thus improve our design, our system could be a good starting point for their own research.