byte sw = 13; 
byte led = 12;
bool ledState = LOW;       
bool buttonState;            
bool lastButtonState = HIGH; 

unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50; 


void setup() {
pinMode(sw, INPUT);
  Serial.begin(115200);  
pinMode(led, OUTPUT);


}

void loop() {
  bool reading = digitalRead(sw);


  
if(reading != lastButtonState) {
 lastDebounceTime = millis();

}
if((millis() - lastDebounceTime) > debounceDelay) {
 if (reading != buttonState) {
      buttonState = reading;
 }
   if (buttonState == LOW) {
        ledState = !ledState;
      }

}

digitalWrite(led, ledState);
lastButtonState = reading;

}