#include <Keyboard.h>

void setup() {
  // put your setup code here, to run once:
  pinMode(4, INPUT);
  Keyboard.begin();

  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  if (digitalRead(4) == HIGH) {
    Keyboard.press('h');
  } else {
    Keyboard.release('h');
  }

}