Hi I am in my final year of uni and for my project I am looking at doing it on a wireless sensor network for a car park application. The thing that I am currently stuck on is that I am trying to define my specifications for the project, in particular the hardware specs. My project is going to be modular and small scale, my design will monitor 6 bays and there will be all most real time updates to a web database. I am struggling to decide on what kind of sensory will be needed, I mean there are a lot of choices and they all could work. Light, infra-red, ultra sonic. But i am aiming for low power consumption. Also I am lost in regards to the communications, what type of wireless comms would be best, what device to choose, what speed. And i will need to justify my choices for each piece of hardware. I guess I am asking if anyone could help me choose or develop a criterion for hardware selection that would be great. Has anyone designed a wireless sensor network? What was your reason for choosing the hardware you used?