General purpose input / output
General-purpose input / output (engl. GPIO - general purpose input / output ) is a common contact pin on an integrated circuit (IC), whose behavior, regardless of whether is freely determined as an input or output contact, by logically programming. GPIO contacts have no purpose, so they are not assigned by default.
connection
A GPIO channel ( port ) is a group of several combined contacts that are addressed as a logical channel.
Application examples
When switched as input, the status of a button - open or closed - can be queried by the IC, for example. Any electrical elements such as light emitting diodes or actuators can be switched on or off as an output (taking into account the permissible current and voltage parameters, possibly indirectly) . Communication protocols such as I²C and Serial Peripheral Interface are also handled via such contacts if the circuit has no or not enough specialized contacts for them; to do this, you have to program the behavior defined in the protocol yourself .