Department of Computer Science & Engineering

1. Department of Computer Science & Engineering REU 2006 – Parking Lot Occupancy Using Wireless Sensor Networks Cristian Castro and César López, Mentors: Dr. Miguel Labrador, Daladier Jabba, and Pedro Wightman • The data received from the WSN was interpreted and saved into a Postgress database that can be in either a PC or an embedded system platform such us the Startgate which has an embedded linux operating system installed[5]. • The final application was tested with the whole kit. 1. Introduction It is common nowadays that it takes a lot of time to find an empty spot in parking lots everywhere[1]. Imagine knowing ahead of time the exact location where you can park. Wireless Sensor Networks (WSN) are a cost effective solution to solve this problem[2]. Besides being cost effective, they have other features such as portability, low maintenance and ease of installation. Therefore, the objective of this project is to develop a system using WSN which has the capability to collect, send and store information about the parking lot occupancy at all times. • The PIR sensor detects just movement. • The cars deflect the earth magnetic field. • Such a deflection does not have a regular behavior in different circumstances. • A state machine model was the solution to solve the problem. • The data is only sent when changes are detected. Furthermore, the battery lifetime can be increased this way. • Data received from the final parking occupancy application. • 3. Results • Data received from the PIR sensors • Data received from the Magnetic sensors. • 2. Methodology • A WSN kit with eight MSP410 (XSM600C) sensor nodes was used [3]. Each node has one magnetic sensor and four passive infrared (PIR) sensors. A base station connected to a laptop was also used in order to collect the data from the sensors. The nodes were programmed in nesC using TinyOS[4]. • 4. Conclusions • Based on these results, WSN are a suitable solution for the stated problem. • The WSN kit was completely characterized. • Each car deflects the earth magnetic field in a different way depending on the material it is made of. • The parking lot occupancy data is now available in a database to be accessed either locally or remotely. • In order to characterize the sensors, an application was developed to calibrate them. This application also reads sensor data and then sends it to the PC to be displayed on the screen. • 5. References • [1]http://escholarship.bc.edu/cgi/viewcontent.cgi?article=1285&context=econ_papers • [2]http://www.intel.com/research/exploratory/wireless_sensors.htm • [3]http://ceti.cs.ohio-state.edu/exscal/ • [4]http://www.tiyos.net/ • [5]http://www.xbow.com/Products/XScale.htm • Several tests were done with a node using the characterization application to analyze the sensors’ behavior. • 6. Acknowledgements • Thanks to our mentors Daladier, Pedro and Dr. Labrador for their assistance. Thanks to our friends Francisco, Daniel and Paul for their collaboration in the tests. • A final application with a parking spot occupancy detection algorithm was designed.