void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  
  pinMode(12, OUTPUT);

  pinMode(18, INPUT_PULLUP);
}

int nowButtonState, oldButtonState;

void loop() {
  // put your main code here, to run repeatedly:
  
  nowButtonState = digitalRead(18);

  if(nowButtonState == LOW && oldButtonState == HIGH )
  {
    digitalWrite(12, !digitalRead(12)); //flip the last valuable to the inverser if last HIGH then LOW
  }
  
  
  //for the poor simulator :(
  delay(100);
  
  oldButtonState = nowButtonState;
  Serial.print(oldButtonState);

}