Time synchronization in Arduino-based wireless sensor networks

Wireless sensor networks have attracted a lot of attention due to their wide variety of applications, ranging from inventory management to battlefield surveillance. In most cases, an accurate time synchronization of the nodes is essential to provide a common time reference and to facilitate coordinated actions. However, important challenges arise when network nodes are clocked by low-cost, low-stability oscillators, besides suffering of strong power consumption and computational capacity constraints. In addition, wireless communication protocols used by those simple nodes often have functional and performance disadvantages. Based on that, this paper presents a synchronization technique for Bluetooth-based sensor networks populated by highly resource constrained sensing nodes. In this paper, the main factors influencing time synchronization are characterized and experimentally validated in a real system, including the Bluetooth communication channels. At the end, the proposed synchronization technique is implemented and evaluated in an Arduino-based wireless sensor network, whose motivational application is the localization of acoustic events.