In this paper we address three challenges that are present when building and analyzing wireless sensor networks (WSN) as part of ubiquitous computing environment: the need for an in-situ user interface, a data logger, and a power consumption meter. Solutions for the above have been presented using laptops, personal digital assistants (PDA), onboard flash memory chips of limited size (usually 1MB), and laboratory test equipment. All of them have a good utility for the right applications. However, considering a certain variety of WSNs, where size, battery life, and cost are crucial, none of the above solutions is satisfactory. In this paper we present a compact, lightweight, low power, and low cost multimodal sensor module SeeMote that meets the stated challenges, and is compatible with the popular MICAz mote. Our module has the following components: (1) a graphical user interface component that combines a color liquid crystal display (LCD) and 5-way buttons, (2) a power meter component that is reconfigurable for attaching various low-power devices, and (3) a data logger component that is interfaced to a removable secure digital (SD) or multimedia memory card (MMC). The module dimensions are 34times58times12 mm. This paper describes the hardware and software design and experiences while developing and using the device. The device is evaluated by comparing its parameters and functionality to laptop and PDA solutions. We conclude that SeeMote is preferred for certain WSNs, such as very large scale, difficult to reach, and wearable WSNs. We also present several applications that use the LCD module, such as the portable frequency spectrum analyzer and remote sensory data display device.
['Leo Selavo', 'Gang Zhou', 'John A. Stankovic']
SeeMote: In-Situ Visualization and Logging Device for Wireless Sensor Networks