During the last decade, Wireless Sensor Networks (WSNs) have been evolving towards more advanced applications using the latest technology breakthroughs. This evolution leads to an important increase of the resources required to cover the needs of these new scenarios. Even though the use of hardware-based solutions had been avoided by the majority of WSN designers, new approaches are being opened to this kind of devices due to their much higher powerful processing capabilities. In this book, a novel hardware-based wireless sensor node architecture with specific energy saving methodologies is presented.