int led=3;
int tipka=2;
int stanje;

void setup() {
  // put your setup code here, to run once:
pinMode(led,OUTPUT);
pinMode(tipka,INPUT_PULLUP);
digitalWrite(led,LOW);
}

void loop() {
  // put your main code here, to run repeatedly:
stanje=digitalRead(tipka);  //pridruženje
if(stanje==HIGH) //usporedba
 digitalWrite(led,LOW);
 else
  digitalWrite(led,HIGH);
 }