enum SystemState {IDLE, PRESS};
SystemState state;
int buttonState = 15;
int ledPin = A14;
int press_time;
float press_start, press_end;
float debounce_start;
int debounce_time;
int prevButton;
int random_no;

void setup() {
  // put your setup code here, to run once:
  pinMode(buttonState, INPUT_PULLUP);
  pinMode(ledPin, OUTPUT);
  press_time = 0;
  state = IDLE;
  prevButton = 1;
  random_no = 500;
  debounce_time = 30;
  digitalWrite(ledPin, LOW);
  SerialUSB.begin(0);
}



void loop() {
  // put your main code here, to run repeatedly:
  pwm_LED();

}

void pwm_LED() {
  switch (state) {
    
    case IDLE:
      SerialUSB.println(press_time);
      SerialUSB.println(random_no);
      if (press_time > random_no) {
        digitalWrite(ledPin, HIGH);
      } else {
        digitalWrite(ledPin, LOW);
      }
      SerialUSB.println(digitalRead(ledPin));
      if (debounce(buttonState, prevButton)) {
        press_start = millis();
        prevButton = !prevButton;
        state = PRESS;
        
      }
    break;
    case PRESS:
      digitalWrite(ledPin, LOW);
      if (debounce(buttonState, prevButton)) {
        press_end = millis();
        press_time = press_end - press_start;
        random_no = random(500);
        state = IDLE;
        prevButton = !prevButton;
      }
    break;
  }
}

int debounce(int button, int previous) {
  if (digitalRead(button) != previous) {
    debounce_start = millis();
  }
  while (millis() - debounce_start < debounce_time) {};
  return digitalRead(button) != previous;
}