#define BLYNK_TEMPLATE_ID "TMPL3S-CRZpDb"
#define BLYNK_TEMPLATE_NAME "virtual reality navigation"
#define BLYNK_AUTH_TOKEN "t75ZG9sv6zSWmofgSK_o1eGVbwOIiN-h"
#define BLYNK_PRINT Serial   
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <WiFi.h>
#include <BlynkSimpleEsp32.h>

char auth[] = "t75ZG9sv6zSWmofgSK_o1eGVbwOIiN-h";
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

#define TRIG_PIN 12
#define ECHO_PIN 14
#define BUZZER_PIN 26

LiquidCrystal_I2C lcd(0x27, 16, 2);

BlynkTimer timer;

int distance = 0;

void setup() {
  Serial.begin(9600);
  Blynk.begin(auth, ssid, pass);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  
  // Initialize LCD
  lcd.init();
  lcd.backlight();
  
  // Setup a function to be called every 1 second
  timer.setInterval(1000L, sendSensorData);
}

void loop() {
  Blynk.run();
  timer.run();
}

BLYNK_WRITE(V1) {
  int pinValue = param.asInt();
  if (pinValue == 1) {
    // Activate buzzer
    tone(BUZZER_PIN, 1000);
  } else {
    // Deactivate buzzer
    noTone(BUZZER_PIN);
  }
}

void sendSensorData() {
  long duration;
  
  // Trigger ultrasonic sensor
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
  // Measure echo duration
  duration = pulseIn(ECHO_PIN, HIGH);
  
  // Calculate distance
  distance = duration * 0.034 / 2;
  
  // Display distance on LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Distance: ");
  lcd.print(distance);
  lcd.print(" cm");
  
  // Send distance value to Blynk app
  Blynk.virtualWrite(V5, distance);
}