One special feature of the Raspberry Pi is its GPIO, or General Purpose Input/Output connector. This is the strip of pins that runs along one side of the Pi, which acts as a connector to a number of physical inputs or outputs.
It is this ability to wire up custom physical inputs, i.e. switches or buttons, that is part of the reason Box Of Stops was written for the Raspberry Pi.
== Setting up a Gpio input ==
In [[Configuration mode]], if you click the plus icon to add a trigger to a [[Stop]], [[Coupler]] or [[Combination]] in the usual way, then the screen will wait for you to press the new input button. Assuming everything has been wired up correctly, the screen will then confirm which button you pressed.
== Sharing Gpio inputs with another application on the Pi ==
By default Box Of Stops will assume it is the only application running on the Raspberry Pi that needs to access the Gpio inputs, and take input from all 17 of them.
To share the inputs with another application, please look in the [[Application properties]] for Box Of Stops. The <tt>pi.input.pins</tt> property can be used to define which pins Box Of Stops should open - more details in the <tt>application.properties.default</tt> file.