#define LED 23
#define BUTTON 22

bool bStatus = 0;
unsigned long bt = 0;

void setup() {
  Serial.begin(9600);
  pinMode(LED, OUTPUT);
  pinMode(BUTTON, INPUT_PULLUP); //  sd nội trở tránh floating state
  bt = millis(); // tương tự halgetick
}

void loop() {
  if(digitalRead(BUTTON) == 0) // an nut
  {
    if(millis() - bt > 100) // khu nhieu, chong rung
    {
      bStatus = !bStatus;
    }
    bt = millis();
  }
  digitalWrite(LED,bStatus);
}