Modulo: A modular sensor network node optimised for research and product development

The paper identifies several key challenges that were experienced by the authors while doing research and development work relating to wireless sensor networks. Some key issues include complexity, outdated platform level designs, lack of flexibility and hardware expenses. The challenges were addressed by designing a new customised mote platform, using a modular design approach. The platform supports both TinyOS and ContikiOS, promoting flexibility and operability. Dual operating system (OS) support allows programmers to choose which OS to use based on the application specific problem that needs to be solved. The mote consists of two modular units that provide processing and communication functionality on one layer and energy storage and harvesting on a second layer. The energy harvesting module uses a solar panel to charge a rechargeable battery pack. Designs were based around minimalistic concepts to minimise cost and reduce hardware complexity. User friendly design was also a key consideration, since the platform is intended to be used by novice programmers to obtain practical experience in sensor networks. The platform can be manufactured in South Africa resulting in an overall cost reduction for small quantities. Future work will include the design of several application specific add-on boards to facilitate field tests in water quality monitoring, gas sensing, smart grid metering, agricultural monitoring and asset tracking.