#define TRIG_PIN 2
#define ECHO_PIN 3
#define PUMP_PIN 4
#define BUTTON_PIN 5

bool glassDetected = false;
bool manualStop = false;
unsigned long lastDetectionTime = 0;

void setup() {
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(PUMP_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  Serial.begin(9600);
}

void loop() {
  long duration, distance;
  
  // Check if the manual stop button is pressed
  if (digitalRead(BUTTON_PIN) == LOW) {
    manualStop = true;
    digitalWrite(PUMP_PIN, LOW); // Turn off the pump
  } else {
    manualStop = false;
  }
  
  // If manual stop is active, exit loop
  if (manualStop) {
    return;
  }
  
  // Clear the trigger pin
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  
  // Send a 10 microsecond pulse to trigger the sensor
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
  // Read the pulse from the echo pin
  duration = pulseIn(ECHO_PIN, HIGH);
  
  // Calculate the distance in cm
  distance = duration * 0.034 / 2;
  
  // Print the distance to the serial monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  
  // Check if the distance is less than a threshold (adjust as needed)
  if (distance < 10) {
    if (!glassDetected) {
      // Activate the pump
      digitalWrite(PUMP_PIN, HIGH);
      lastDetectionTime = millis(); // Record the time of glass detection
      glassDetected = true;
    } else {
      // Check if 4 seconds have passed since the last detection
      if (millis() - lastDetectionTime >= 4000) {
        digitalWrite(PUMP_PIN, LOW); // Turn off the pump
      }
    }
  } else {
    glassDetected = false;
    digitalWrite(PUMP_PIN, LOW); // Ensure the pump is off when no glass is detected
  }
  
  // Delay before the next reading
  delay(100);
}