Can the two GPIOs on the Fastrack be used to sense a simple open/close contact?
ie, no externally applied voltage, just the contact connected between the two GPIOs
GPIO4 -------+ | | \ \ Contact \ | | GPIO5 -------+
Could I then set one GPIO as an output, the other as an input, and detect whether the contact is open or closed?
Would I need to drive the output High or Low?
This would rely upon a GPIO set for input giving a defined value when open-circuit, and the other GPIO driving it to the opposite state when the contact closes.
Would this work?