#define BLYNK_TEMPLATE_ID "TMPL3rTNloqmQ"
#define BLYNK_TEMPLATE_NAME "IOT PROJECT"
#define BLYNK_AUTH_TOKEN "jAeENxYkIqcUEIcG85MfX5zsvuS23olU"  // Replace with your Blynk Auth Token

#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Wi-Fi credentials
char ssid[] = "Wokwi-GUEST";  // Replace with your Wi-Fi SSID
char pass[] = "";  // Replace with your Wi-Fi password

// Pin Definitions
#define TRIG_PIN 5     // GPIO5 (D5) for Ultrasonic Trig
#define ECHO_PIN 18    // GPIO18 (D18) for Ultrasonic Echo
#define GREEN_LED_PIN 2 // GPIO2 for Green LED (safe level)
#define RED_LED_PIN 15 // GPIO15 for Red LED (nearly full)
#define BUZZER_PIN 4   // GPIO4 for Buzzer (audible alert)

// Initialize LCD (I2C address 0x27, 16 chars, 2 lines)
LiquidCrystal_I2C lcd(0x27, 16, 2);

long duration;
int distance;

void setup() {
  // Initialize hardware components
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  lcd.init();       // Initialize the LCD
  lcd.backlight();  // Turn on the backlight

  Serial.begin(115200); // For debugging

  // Initialize Blynk
  Blynk.begin(BLYNK_AUTH_TOKEN, ssid, pass);
}

void loop() {
  // Send a 10us pulse to start measurement
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

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

  // Calculate the distance in cm
  distance = duration * 0.034 / 2;

  // Print distance on Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Display the distance on the LCD
  lcd.setCursor(0, 0);
  lcd.print("Waste Level:");
  lcd.setCursor(0, 1);
  lcd.print(distance);
  lcd.print(" cm");
  delay(500); // Brief delay before clearing the LCD

  lcd.clear(); // Clear LCD for the next update

  // Update Blynk Gauge Widget with waste level
  Blynk.virtualWrite(V1, distance);

  // Check waste level and control LEDs, Buzzer, and Blynk widgets
  if (distance < 10) {
    digitalWrite(RED_LED_PIN, HIGH);   // Turn on Red LED
    digitalWrite(GREEN_LED_PIN, LOW);  // Turn off Green LED
    digitalWrite(BUZZER_PIN, HIGH);    // Turn on Buzzer
    delay(500);
    digitalWrite(BUZZER_PIN, LOW);    // Turn off Buzzer
    delay(500);

    Blynk.virtualWrite(V3, 255); // Turn on Red LED in Blynk
    Blynk.virtualWrite(V2, 0);   // Turn off Green LED in Blynk

    // Send a notification via Blynk
     Blynk.logEvent("Warning", "Warning: Waste level is critically low!");
    
  } else {
    digitalWrite(RED_LED_PIN, LOW);    // Turn off Red LED
    digitalWrite(GREEN_LED_PIN, HIGH); // Turn on Green LED
    digitalWrite(BUZZER_PIN, LOW);     // Turn off Buzzer

    Blynk.virtualWrite(V3, 0);   // Turn off Red LED in Blynk
    Blynk.virtualWrite(V2, 255); // Turn on Green LED in Blynk
  }

  Blynk.run(); // Run Blynk to process incoming commands

  delay(1000); // Wait 1 second before next measurement
}