#define TRIG_PIN 19   // Ultrasonic sensor TRIG pin
#define ECHO_PIN 18   // Ultrasonic sensor ECHO pin
#define LED_PIN 12    // LED indicator pin

long duration;
int distance;

void setup() {
  Serial.begin(115200);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(LED_PIN, OUTPUT);
}

void loop() {
  // Trigger the ultrasonic sensor
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // Read the echo time
  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 below a certain threshold (e.g., 10 cm)
  if (distance < 10) {
    digitalWrite(LED_PIN, HIGH); // Turn on the LED if water is low
  } else {
    digitalWrite(LED_PIN, LOW);  // Turn off the LED if water level is okay
  }

  delay(500); // Wait before the next measurement
}