ABSTRACT
This chapter focuses on hardware implementation of wireless sensor networks where location information is of paramount importance. It describes a low-power miniaturized navigation system design for sensor nodes in wireless sensor networks (WSNs), where cost, size, and energy consumption are focal concerns. The components of the system can be divided into five main blocks: data acquisition components: inertial sensors, global positioning system (GPS), magnetic sensor; data processing unit: digital signal processor (DSP); power management unit: microcontroller; wireless transceiver; and power supply. The GPS module transmits data using the universal asynchronous receiver/transmitter interface and it uses National Marine Electronics Association data communication protocol to transmit position information. To improve the real-time performance and reduce the data acquisition overheads, field-programmable gate arrays are used in many GPS/inertial navigation system applications to assist the DSP in receiving navigation data. When the WSN node is stationary and its position is fixed, both GPS and inertial sensors will be turned off until it starts to move again.
