#define BLYNK_TEMPLATE_ID "TMPL6ej14n0Vo"
#define BLYNK_TEMPLATE_NAME "Quickstart Template"
#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>
#include <NewPing.h>

// Your Wi-Fi credentials
char ssid[] = "Wokwi-GUEST";
char pass[] = "";

// Your Blynk authentication token
char auth[] = "A-TrV61D62-nRZMRp-f9FGypdohD46YG";

// Define the GPIO pins for the ultrasonic sensor
#define trigPin 2
#define echoPin 4
#define buzzer 18
#define ledred 19

// Create an instance of the NewPing library
NewPing sonar(trigPin, echoPin);

void setup() {
  Serial.begin(115200);
  Blynk.begin(auth, ssid, pass);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(ledred, OUTPUT);
}

void controlBuzzerAndLEDs(long distance) {
  if (distance < 201) {
    // If the distance is less than 199
    digitalWrite(ledred, HIGH);
    digitalWrite(buzzer, HIGH);
    delay(100); // Delay for buzzer ON duration
    digitalWrite(buzzer, LOW);
    delay(100); // Delay for buzzer OFF duration
  } else {
    // If the distance is greater than or equal to 199 cm, turn off the red LED and turn off the buzzer
    digitalWrite(ledred, LOW);
    digitalWrite(buzzer, LOW);
  }
}

void loop() {
  Blynk.run();

  long duration, distance;
  
  // Trigger ultrasonic sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Read the echo pulse
  duration = pulseIn(echoPin, HIGH);

  // Calculate distance in centimeters
  distance = (duration / 2) / 29.1;

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Check the distance and control LEDs and buzzer
  controlBuzzerAndLEDs(distance);

  // Send the distance data to Blynk
  Blynk.virtualWrite(V4, distance);  // Use V4 as a display widget in your Blynk app
  
  delay(1000); // Delay between measurements
}