// Define the pins for the ultrasonic sensor
const int trigPin = 11;
const int echoPin = 12;

// Define the pins for the LEDs
const int ledPins[] = {8,7,6,5,4,3,2};
const int numLeds = 7;  // Number of LEDs

void setup() {
  // Initialize ultrasonic sensor pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  // Initialize LED pins
  for (int i = 0; i < numLeds; i++) {
    pinMode(ledPins[i], OUTPUT);
  }

  // Start with all LEDs off
  for (int i = 0; i < numLeds; i++) {
    digitalWrite(ledPins[i], LOW);
  }
}

void loop() {
  // Variables to store distance measurement
  long duration, distance;

  // Trigger the ultrasonic sensor to send a pulse
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Measure the pulse from the echo pin
  duration = pulseIn(echoPin, HIGH);

  // Calculate the distance in centimeters
  distance = (duration / 2) / 29.1;

  // Update LED indicators based on distance
  for (int i = 0; i < numLeds; i++) {
    if (distance >= (i + 1) * 10) {
      digitalWrite(ledPins[i], HIGH);
    } else {
      digitalWrite(ledPins[i], LOW);
    }
  }
}