// Constants for digital pins
const int trigPin = 13;  // Digital pin for the trigger signal
const int echoPin = 12;  // Digital pin for the echo signal
const int buzzerPin1 = 4; // Digital pin for the buzzer
const int buzzerPin2 = 3; // Digital pin for the buzzer
const int buzzerPin3 = 2; // Digital pin for the buzzer
const int buzzerPin4 = 1; // Digital pin for the buzzer
// Constant for the analog pin
const int potPin = A0;   // Analog pin for the potentiometer

// Variables for the ultrasonic sensor
float duration, distance;

// Variable for the potentiometer value
int potValue;

void setup() {
  // Setup for digital pins
  pinMode(trigPin, OUTPUT);  // Set the trigger pin as an output
  pinMode(echoPin, INPUT);   // Set the echo pin as an input
  pinMode(buzzerPin1, OUTPUT); // Set the buzzer pin as an output
  pinMode(buzzerPin2, OUTPUT); // Set the buzzer pin as an output
  pinMode(buzzerPin3, OUTPUT); // Set the buzzer pin as an output
  pinMode(buzzerPin4, OUTPUT); // Set the buzzer pin as an output
  // No setup for analog pin required (no need to set pinMode for analog input)
  
  // Initialize serial communication
  Serial.begin(9600);
}

void loop() {
  readUltrasonic();
  readPot();
  controlBuzzer();
  delay(distance);
}

// Reading a digital input
void readUltrasonic() {
 // Send a low pulse to ensure the trigger pin is low
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);  // Wait for 2 microseconds

  // Send a high pulse to trigger the ultrasonic sensor
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);  // Wait for 10 microseconds to ensure the pulse is sent
  digitalWrite(trigPin, LOW);  // Set the trigger pin back to low

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

  // Calculate the distance based on the duration
  // Speed of sound is approximately 0.0343 cm/us
  // Dividing by 2 because the pulse travels to the object and back
  distance = (duration * 0.0343) / 2;

  // Display the calculated distance
  Serial.print("Distance: ");
  Serial.println(distance);
}

// Reading an analog input
void readPot() {
// Read the analog input from the potentiometer
  potValue = analogRead(potPin);  // Read the value from the potentiometer (0-1023)
  
  // Display the potentiometer value
  Serial.print("Potentiometer Value: ");
  Serial.println(potValue);
}

void controlBuzzer() {
    // Map the potentiometer value (0-1023) to a PWM value (0-255)
  int pwmValue = map(potValue, 0, 1023, 0, 255);
  
  // Generate the tone at a specific frequency
  tone(buzzerPin1, pwmValue, distance);

  delay(distance + 50);

  tone(buzzerPin2, (pwmValue/2 + (pwmValue/4)), distance);

  delay(distance + 50);

  tone(buzzerPin3, (pwmValue/2), distance);
  
  delay(distance + 50);

  tone(buzzerPin4, (pwmValue/4), distance);


}