Embodiments of computer-implemented methods, systems, computing devices, and computer-readable media are described herein for transitioning a computing device between a first state in which the computing device uses a first amount of power and a second state in which the computing device uses a second, greater amount of power. The computing device may include a shared wake pin to which a first external device and a second external device may be operably coupled, and a communication bus to which the first external device is connected and the second external device is not. Responsive to receipt of a wake signal at the wake pin, the computing device may transition between states, send an instruction to the first external device over the communication bus, and determine whether the first or second external device initiated the wake signal based on a response at the wake pin.