While the Arduino family of boards connect to your computer using a USB virtual serial port, the ATmega ones have an actual serial connection on-board.

You can read the state of a button using Arduino and a few lines of code. The actual state is shown in the Serial Monitor window as 0 or 1, 0 meaning the button is not pressed and 1 that the button is ...

An Arduino Uno provides the processing power and drives the serial monitor. A joystick and a Hitachi H48C accelerometer are mounted on a breadboard and wired to the Uno.