const int trig = 33;
const int echo = 32;
const int relay = 4;

  long duration;
  int distance;
  int threshold = 61;
  int count = 0;
  int wait = 0;
  int tFlush = 0;


  const int flowsensor = 16;
  const int ledPin = 17;
  volatile int flowDetected = 0;
  unsigned long lastFlowTime = 0;
  const unsigned long flowTimeout = 1000; 

  void flowChange() {
    flowDetected = 1;
    lastFlowTime = millis();
  }

void setup() {
  pinMode(trig, OUTPUT); 
  pinMode(echo, INPUT); 
  pinMode(relay, OUTPUT);
  pinMode(flowsensor, INPUT);
  digitalWrite(flowsensor, HIGH);
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
  Serial.begin(115200);
  attachInterrupt(digitalPinToInterrupt(flowsensor), flowChange, FALLING);
}

void loop() {
// Clears the trigPin
digitalWrite(trig, LOW);
delayMicroseconds(2);

// Sets the trigPin on HIGH state for 10 micro seconds
digitalWrite(trig, HIGH);
delayMicroseconds(10);
digitalWrite(trig, LOW);

// Reads the echoPin, returns the sound wave travel time in microseconds
duration = pulseIn(echo, HIGH);

// Calculating the distance
distance = duration * 0.034/2;

if (distance <= threshold){
digitalWrite(relay, LOW);
}else {
digitalWrite(relay, HIGH);
}

unsigned long currentTime = millis();
if (digitalRead(relay) == HIGH){
if (flowDetected && (currentTime - lastFlowTime < flowTimeout)) {
    Serial.println("Water flow detected!");
    digitalWrite(ledPin, HIGH); // Turn on the LED
  }
  delay(1000); // Adjust delay as needed
}
if (digitalRead(relay) == LOW){
if (flowDetected && (currentTime - lastFlowTime < flowTimeout)) {
    Serial.println("Water flow detected!");
    digitalWrite(ledPin, HIGH); // Turn on the LED
  } else {
    Serial.println("No Water flow detected!");
    digitalWrite(ledPin, LOW); // Turn off the LED
    flowDetected = 0; // Reset flow detection when there is no flow
  }
delay(1000); // Adjust delay as needed
}

}