//dieu khien chuc nang vua nhann input vua cho ra out put
#define led 2 // ten la led va gia tri thay the la so 2
#define button 0 // dinh nghia chan so 0
void setup() {
  pinMode (button, INPUT_PULLUP);
  pinMode (led, OUTPUT);
}
void loop() {
  static bool buttonState = HIGH; // luu tam thoi o muc cao
    if(digitalRead(button)==LOW){ // lenh doc nut nhan va kiem tra vs dkien trong ngoac
      if(buttonState==HIGH) // muc cao + nhan nut se cho ra nngo ra ....
      {
        digitalWrite(led, !digitalRead(led));
        delay (200);
        buttonState=LOW;
      }
}
else
{
buttonState=HIGH;
}
}