This report goes into discussion of a particular application, a rainfall measuring device, with wireless devices developed by Crossbow Technology and students and faculty of the University of California Berkeley. The first several pages introduce the tasks of the Wireless Sensor Networks Group followed by a detailed report of the wireless equipment interfacing successfully with the rain gauge application. A step-by-step technical approach was taken to inform the reader of the uses of this wireless technology. To conclude the senior project, results were recorded from the application demonstration to verify the completeness of the senior project.-　　This report goes into discussion of a particular application, a rainfall measuring device, with wireless devices developed by Crossbow Technology and students and faculty of the University of California Berkeley.　The first several pages introduce the tasks of the Wireless Sensor Networks Group followed by a detailed report of the wireless equipment interfacing successfully with the rain gauge application.　A step-by-step technical approach was taken to inform the reader of the uses of this wireless technology.　To conclude the senior project, results were recorded from the application demonstration to verify the completeness of the senior project.