const int BUTTON = 21;
bool state = false;


void setup() {
  Serial.begin(115200);
  pinMode(21, INPUT_PULLUP);
  pinMode(19, OUTPUT);
  
}

void loop() {
  
  if(digitalRead(BUTTON)== 0 && state == false){
    digitalWrite(19,HIGH);
    Serial.println("Button Pressed");
     Serial.println("---");
     state = true;}

}