// Define the analog pin
const int analogPin = A0;

// Constants for converting the analog reading to distance
const int minDistance = 10;  // Minimum distance the sensor can measure in cm
const int maxDistance = 80;  // Maximum distance the sensor can measure in cm
const float minVoltage = 0.4; // Minimum voltage at 10 cm (0.4V)
const float maxVoltage = 3.1; // Maximum voltage at 80 cm (3.1V)

void setup() 
{
  Serial.begin(9600); // Initialize serial communication
}

void loop() 
{
  // Read the analog voltage from the sensor
  int sensorValue = analogRead(analogPin);
  float voltage = sensorValue * (5.0 / 1023.0); // Convert the reading to voltage

  // Print the raw sensor value and voltage for debugging
  Serial.print("Sensor Value: ");
  Serial.print(sensorValue);
  Serial.print("  Voltage: ");
  Serial.print(voltage);
  Serial.println(" V");

  // Convert the analog reading to a distance in centimeters
  float distance = convertVoltageToDistance(voltage);

  // Print the distance to the serial monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  delay(500); // Wait 500 milliseconds before the next reading
}

// Function to convert voltage to distance
float convertVoltageToDistance(float voltage) 
{
  float distance;

  // If voltage is outside the expected range, set it to max/min distance
  if (voltage <= minVoltage) 
  {
    distance = minDistance;
  } 
  else if (voltage >= maxVoltage) 
  {
    distance = maxDistance;
  } 
  else 
  {
    // Convert voltage to distance based on a linear approximation
    distance = 27.86 / (voltage - 0.42);
  }

  return distance;
}