Site Survey Tool for Mica Motes Justin Comroe Sean Williams Mike Jonas
Motivation • Site survey tools are often proprietary to specific hardware. • No tool for mica motes could be found. • A practical solution for a small environment.
Steps to Achievement • Interface GPS unit with Windows Mobile on the PDA and test GPS accuracy using HDOP indicator. • Interface Mica motes with PDA and write broadcast and logging code. • Profile signal strength as a function of distance for our hardware. • Generate a contour map of signal strength for our landscape and display this to the user in a meaningful way.
GPS Accuracy Profiling • Walk to Whataburger • Street Grid allows us to gauge inaccuracies easily • Day and Night samples • HDOP relevance, 1 HDOP~= 3 feet of error
Signal Strength Profiling • A default assumption of signal strength as a function of distance is necessary for mapping using limited data sets. • Place motes in a static position and then take measurements along a grid and map the connectivity at each point. 1 4 3 2 Test 1
Graphical Display • Displays for the user a best guess scenario of signal strength at all points in the environment. • We use our signal strength profile for original values and then bend the contours to fit the data the user provides.
Graphical Display • Conceptual Design
Accomplishments • We have succeeded in interfacing all hardware components necessary to complete our goal. • We have created a system for learning the signal strength of any mote hardware, though our system at the moment assumes a homogenous mote environment. • We have devised a method for generating a signal strength contour map with minimal upfront cost.