Reading AVR button status using WinAVR
If you want to bring some interactivity to your embedded projects, one option is to add buttons. This allows you to control program flow, set parameters, and much more. Few words about AVR ports. AVR Port pins can be configured as input or output. See table for all general pin configurations: DDRx register is the so-called direction register; PORTx – is port output register; PINx – is pin input register;