#define BLYNK_TEMPLATE_ID "TMPL3MG913jg-"
#define BLYNK_TEMPLATE_NAME "Visually impaired Navigation"

#include <BlynkSimpleEsp32.h>
#include <WiFi.h>

// WiFi credentials
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// Blynk authentication token
char auth[] = "7_DXAOtUjVTC1WxKbKu0QrGd1wnOyQi1";

const int trigPin = 13;
const int echoPin = 5;
const int ledPin = 12;

long duration;
int distance;

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
  
  // Connect to WiFi and Blynk
  setupBlynk();
}

// Function to initialize WiFi and Blynk
void setupBlynk() {
  Blynk.begin(auth, ssid, pass);
}

void loop() {
  // Clear the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  // Sets the trigPin on HIGH state for 10 microseconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  
  // Calculating the distance
  distance = duration * 0.034 / 2; // Speed of sound wave divided by 2 (go and back)
  
  // Prints the distance on the Serial Monitor
  Serial.print("Distance: ");
  Serial.println(distance);

  // If distance is less than 20 cm, turn on the LED
  if (distance < 20) {
    digitalWrite(ledPin, HIGH);
  } else {
    digitalWrite(ledPin, LOW);
  }

  // Run Blynk
  Blynk.run();
  
  delay(500);
}