In addition to the sensor module, the energy-harvesting node has further sensing capabilities. The CC2430 has a built-in temperature sensor that can be used to measure the ambient temperature around the microprocessor. Further sensing abilities are provided by virtue of the energy-harvesting modules that have been attached. For example, a variation in the output level from the solar module may indicate the passing of something over the node, causing a shadow to fall on the solar module. Likewise, an increase in the vibration level measured by examining the instantaneous power output of the vibration generator may indicate that the structure to which it is attached is under a greater load, for instance, due to the travel of people or vehicles.