#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>

char auth[] = "ZhW0EitF223jx_np5bMUQKpmyU04uFi-";  // Enter your authentication token here

// WiFi credentials
char ssid[] = "YourNetworkSSID";
char pass[] = " ";

// 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;

void setup() {
  Serial.begin(9600);

  // Connect to WiFi
  Blynk.begin(auth, ssid, pass);

  // Initialize the LCD
  lcd.begin(16, 2);
  
  // Initialize the buzzer
  pinMode(buzzerPin, OUTPUT);
  
  // 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);
  
  // Display distances on the LCD
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("B1:");
  lcd.print(distance1);
  lcd.print("cm ");
  lcd.setcursor(8,0);
  lcd.print("B2");
  lcd.print(distance2);
  lcd.print("cm");
  lcd.setCursor(0, 1);
  lcd.print("B3:");
  lcd.print(distance3);
  lcd.print("cm");
  
  // Send distances to Blynk
  Blynk.virtualWrite(V1, distance1);  // Virtual pin V1 represents distance of Bin 1
  Blynk.virtualWrite(V2, distance2);  // Virtual pin V2 represents distance of Bin 2
  Blynk.virtualWrite(V3, distance3);  // Virtual pin V3 represents distance of Bin 3

  // Check if any bin is full (e.g., distance < 10 cm)
  if (distance1 < 10 || distance2 < 10 || distance3 < 10) {
    digitalWrite(buzzerPin, HIGH); // Activate buzzer
    Blynk.notify("Bin is 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;
}