#define BLYNK_TEMPLATE_ID "TMPL3v7LlK874"
#define BLYNK_TEMPLATE_NAME "smart campus waste management system with Blynk"

#include <LiquidCrystal.h>
#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>

// Blynk authentication token
char auth[] = "ZhW0EitF223jx_np5bMUQKpmyU04uFi-";

// Wi-Fi credentials
char ssid[] = "YourNetworkSSID";    // Replace with your network SSID
char pass[] = "YourNetworkPassword"; // Replace with your network password

// LCD pin configuration
const int rs = 23, en = 22, d4 = 19, d5 = 18, d6 = 5, d7 = 4;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

// Ultrasonic sensor pins
const int trigPin1 = 5, echoPin1 = 18;
const int trigPin2 = 17, echoPin2 = 16;
const int trigPin3 = 4, echoPin3 = 2;

// Buzzer pin
const int buzzerPin = 21;

// Maximum distance in cm (adjust according to your bin height)
const long maxDistance = 400;

void setup() {
  Serial.begin(9600);
  
  // Connect to Wi-Fi and Blynk
  Blynk.begin(auth, ssid, pass);

  // Initialize the LCD
  lcd.begin(16, 2);
  
  // Initialize the buzzer
  pinMode(buzzerPin, OUTPUT);
  digitalWrite(buzzerPin, LOW); // Ensure buzzer is off initially
  
  // Initialize ultrasonic sensors
  pinMode(trigPin1, OUTPUT);
  pinMode(echoPin1, INPUT);
  pinMode(trigPin2, OUTPUT);
  pinMode(echoPin2, INPUT);
  pinMode(trigPin3, OUTPUT);
  pinMode(echoPin3, INPUT);
}

void loop() {
  Blynk.run();

  // Measure distance from each sensor
  long distance1 = measureDistance(trigPin1, echoPin1);
  long distance2 = measureDistance(trigPin2, echoPin2);
  long distance3 = measureDistance(trigPin3, echoPin3);
  
  // Calculate bin fill levels
  long fillLevel1 = maxDistance - distance1;
  long fillLevel2 = maxDistance - distance2;
  long fillLevel3 = maxDistance - distance3;

  // Display distances on the LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("B1:");
  lcd.print(fillLevel1);
  lcd.print("cm B2:");
  lcd.print(fillLevel2);
  lcd.print("cm");
  lcd.setCursor(0, 1);
  lcd.print("B3:");
  lcd.print(fillLevel3);
  lcd.print("cm");
  
  // Send distances to Blynk
  Blynk.virtualWrite(V1, fillLevel1); // Virtual pin V1 represents distance of Bin 1
  Blynk.virtualWrite(V2, fillLevel2); // Virtual pin V2 represents distance of Bin 2
  Blynk.virtualWrite(V3, fillLevel3); // Virtual pin V3 represents distance of Bin 3

  // Check if any bin is full (e.g., distance < 10 cm)
  if (fillLevel1 > 390 || fillLevel2 > 390 || fillLevel3 > 390) {
    digitalWrite(buzzerPin, HIGH); // Activate buzzer
    Blynk.notify("One or more bins are full!"); // Send notification to Blynk app
  } else {
    digitalWrite(buzzerPin, LOW); // Deactivate buzzer
  }
  
  delay(1000); // Wait for 1 second before the next measurement
}

long measureDistance(int trigPin, int echoPin) {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  long duration = pulseIn(echoPin, HIGH);
  long distance = duration * 0.034 / 2;
  return distance;
}