Using Networked Sensors to Detect Ambient Light

An understanding of the capabilities of the Mica mote light sensors is currently limited. To determine how much information data from the light sensors reveals about the environment, we performed a series of experiments designed to test the sensitivity of the light sensors to the time of day, the presence/absence of close objects, and different colors. Measuring the ambient light alone, we discovered that the light sensors can provide an approximate gauge of the time of day (i.e., morning, noon, evening). Depending on the object size, there is a definite range within which an object's presence can be detected by the sensor motes. Beyond that range, the object cannot be clearly detected. The light sensors can also distinguish between different colored environments. Finally, using a six-sided sensor, we can determine the direction of a light source. We discuss these findings in this paper, as well as the limitations of the mote light sensors.