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

#define TRIG_PIN 12
#define ECHO_PIN 13
#define BUZZER_PIN 14
#define WIFI_LED_PIN 2

char auth[] = "YourAuthTokenHere";
char ssid[] = "YourWiFiSSIDHere";
char pass[] = "YourWiFiPasswordHere";
char blynk_template_id[] = "YourTemplateIDHere";

BlynkTimer timer;
long distance;

void sendDistanceToBlynk() {
  distance = constrain(distance, 1, 50);
  Blynk.virtualWrite(V2, distance);
}

void setup() {
  Serial.begin(115200);
  pinMode(WIFI_LED_PIN, OUTPUT);
  digitalWrite(WIFI_LED_PIN, LOW);
  WiFi.begin(ssid, pass);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  digitalWrite(WIFI_LED_PIN, HIGH);
  Blynk.config(auth);
  while (!Blynk.connected()) {
    if(Blynk.connect()) {
      Blynk.virtualWrite(BLYNK_TEMPLATE_ID, blynk_template_id);
      break;
    }
    delay(1000);
  }
  timer.setInterval(1000L, sendDistanceToBlynk);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
}

void loop() {
  Blynk.run();
  timer.run();
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long duration = pulseIn(ECHO_PIN, HIGH);
  distance = duration * 0.034 / 2;
  if (distance < 50) {
    tone(BUZZER_PIN, 1000);
  } else {
    noTone(BUZZER_PIN);
  }
  delay(100);
}