#include <Keyboard.h>
int buttonPin = 9;  // Set a button to any pin

void setup()
{
  pinMode(buttonPin, INPUT_PULLUP);  // Set the button as an input
  Keyboard.begin();
}

void loop()
{
  if (digitalRead(buttonPin) == 0)  // if the button goes low
  {
    Keyboard.press('z');  // send a 'z' to the computer via Keyboard HID     // delay so there aren't a kajillion z's
  }else{
    Keyboard.releaseAll(); 
  }
  delay(50);
}