//DeafGuard Project

//In the simulation of this program, the Wokwi platform was used.

//The very basic components such as the transistor of which we need in building our device is not on the platform.

//But this code I believe would work, if our calculations are done right.

//A vibration motor is also not in the platform, but using a LED in place of it, helps us understand the logic of fthe code.

// Ultrasonic sensor pins
const int trigPin = 3; // Trig pin connected to D3
const int echoPin = 2; // Echo pin connected to D2

// Vibration motor pin
//(Using a led in place of the motor, becuase there is no vibration motor in Wokwi)
const int ledPin = 10; // Motor connected to D10

// Distance threshold in centimeters (2.10 meters)
const int thresholdDistance = 210; 

void setup() {
  // Initialize serial communication (optional for debugging)
  Serial.begin(115200);
  
  // Set up the pin modes for ultrasonic sensor
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  
  // Set up the pin mode for the vibration motor
  pinMode(ledPin, OUTPUT);
  
  // Start with the vibration motor off
  digitalWrite(ledPin, LOW);
}

void loop() {
  long duration, distance;
  
  // Send a pulse from the ultrasonic sensor's Trig pin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  // Read the pulse duration from the Echo pin
  duration = pulseIn(echoPin, HIGH);
  
  // Calculate distance in centimeters (duration in microseconds / 58 = distance in cm)
  distance = duration / 58;
  
  // Print distance for debugging (optional)
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  
  // If the object is within the threshold distance, activate the vibration motor 
  //(Using a led in place of the motor, becuase there is no vibration motor in Wokwi)
  if (distance > 0 && distance <= thresholdDistance) {
    digitalWrite(ledPin, HIGH); // Turn on the motor
  } else {
    digitalWrite(ledPin, LOW);  // Turn off the motor
  }
  
  // Short delay before next measurement
  delay(200); // 200 milliseconds
}