#define BLYNK_TEMPLATE_ID "TMPL3byTYwj6x"
#define BLYNK_TEMPLATE_NAME "ultrasonic"
#define BLYNK_AUTH_TOKEN "3r9UY-MJ1diTSBqTRrKjKxPL5nh8IMWm"

#include <WiFi.h>
// #include <ESP8266WiFiClient.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>
#include <ESP32Servo.h>

char auth[] = BLYNK_AUTH_TOKEN;
char ssid[] = "LPUWireless";
char pass[] = "123456789a";

const int trigPin = 12;
const int echoPin = 13;
const int servoPin = 4;
long duration;
int distance;
Servo myServo;

BLYNK_WRITE(V1) {
  int servoPosition = param.asInt();
    myServo.write(servoPosition);
    }

void setup() {
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  myServo.attach(servoPin);
  Serial.begin(9600);
  Blynk.begin(auth, ssid, pass);
  }

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;
  Serial.print("Distance=");
  Serial.println(distance);

  Blynk.run();

  Blynk.virtualWrite(V0, distance);

  delay(500);
  }