As the rapid pace of smartphone improvements drives consumer appetites for the latest and greatest devices, the hidden cost is millions of tons of e-waste containing hazardous chemicals and difficult to dispose of safely. Studies show that smartphone users are replacing their devices every 18 months, almost three times faster than desktop computers, producing millions of discarded smartphones each year that end up lying in desk drawers, buried in landfills, or shipped to third-world countries where they are burned to extract precious metals, a process that damages both the health of those involved and the environment.
Fortunately, the capabilities of discarded smartphones make them ideal for reuse. Instead of ending up in a landfill, a discarded smartphone could be integrated into a home security system or transformed into a health care device for the elderly. In this paper, we evaluate using discarded smartphones to replace traditional sensor network "motes". Compared with motes, discarded devices have many advantages: price, performance, connectivity, interfaces, and ease of programming. While the main question is whether their energy consumption is low enough to enable harvesting solutions to allow continuous operation, we present preliminary results indicating that this may be possible.