In this project, we focus on development and deployment of Ultra-low power Pyro-electric Infrared sensors (PIR) based systems inside a compound for the purposes of intrusion detection. The detection capabilities of these systems are augmented by the use of sophisticated detection and classification algorithms and a Wireless Sensor Network (WSN) backbone. As a supplement to intrusion detection, we also explore the options to capture the intrusion as an image or a video. Our team at DESE focuses on developing these PIR sensor systems, energy harvesting electronics and security aspect of the WSN. The novelty of the systems prototyped in our lab lies in the additional design features implemented and industrial design packaging. Also, as security is a critical part of WSN, developing algorithms to protect these WSNs is emphasised.