#include "Keyboard.h"

const int buttonPin = 4; // input pin for pushbutton
int previousButtonState = HIGH; // for checking the state of a pushButton
int counter = 0; // button push counter
void setup() {
   pinMode(buttonPin, INPUT); // make the pushButton pin an input:
   Keyboard.begin(); // initialize control over the keyboard:
}
void loop() {
   int buttonState = digitalRead(buttonPin); // read the pushbutton:
   if ((buttonState != previousButtonState)&& (buttonState == HIGH)) // and it's currently pressed: {
      // increment the button counter
      counter++;
      // type out a message
      Keyboard.print("You pressed the button ");
      Keyboard.print(counter);
      Keyboard.println(" times.");
   }
   // save the current button state for comparison next time:
   previousButtonState = buttonState;
}