Introduction

A Smart Waste Management System is an IoT-based solution designed to monitor and manage garbage bins efficiently. It automatically detects the fill level of bins and alerts municipal authorities when a bin is full, improving cleanliness, hygiene, and urban waste collection efficiency.

This project combines ultrasonic sensors, microcontrollers, and IoT platforms for real-time monitoring.

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Objective of the Project

• To detect the level of waste in garbage bins.
• To send alerts to municipal authorities when bins are full.
• To reduce manual inspection and improve waste collection efficiency.
• To implement IoT monitoring for multiple bins across a city or campus.

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Working Principle

The system works using ultrasonic sensors that measure the distance between the top of the bin and the garbage inside.

Step-by-Step Working

1. Ultrasonic sensors (HC-SR04) measure the distance between the sensor and the garbage level.
2. The ESP32/ESP8266 microcontroller reads the sensor data.
3. If the garbage level exceeds a threshold (e.g., bin is 80% full), an alert is sent to the IoT platform (ThingSpeak, Blynk, or Firebase).
4. Optional: LEDs or buzzers can indicate the bin status locally.
5. Authorities can monitor multiple bins on a central IoT dashboard.

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Components Required

• ESP32 / ESP8266 Microcontroller
• Ultrasonic Sensor (HC-SR04)
• Jumper Wires
• Breadboard / PCB
• Buzzer or LED (optional for alerts)
• IoT Platform (ThingSpeak, Blynk, or Firebase)
• 5V Power Supply

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Circuit Diagram

Connections (Single Bin Setup)

Ultrasonic Sensor HC-SR04:
VCC -> 5V
GND -> GND
Trig -> GPIO5 (ESP32)
Echo -> GPIO18 (ESP32)

ESP32:
VCC -> 5V
GND -> GND

Optional:
Buzzer -> GPIO19 (ESP32) through a resistor
LED -> GPIO21 (ESP32) through a resistor

Note: Multiple bins can use multiple ultrasonic sensors, each connected to different GPIO pins, all sending data to the same IoT platform.

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Arduino/ESP32 Code Example (IoT Monitoring)

#include <WiFi.h>
#include "ThingSpeak.h"

#define TRIG_PIN 5
#define ECHO_PIN 18
#define BUZZER_PIN 19

const char* ssid = "Your_WiFi_SSID";
const char* password = "Your_WiFi_PASSWORD";
WiFiClient client;

unsigned long channelID = 123456; // ThingSpeak Channel ID
const char* writeAPIKey = "YOUR_API_KEY";

void setup() {
  Serial.begin(115200);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);

  WiFi.begin(ssid, password);
  Serial.print("Connecting to Wi-Fi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("Connected!");

  ThingSpeak.begin(client);
}

long getDistance() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  long duration = pulseIn(ECHO_PIN, HIGH);
  long distance = duration * 0.034 / 2; // Distance in cm
  return distance;
}

void loop() {
  long distance = getDistance();
  Serial.print("Distance: "); Serial.println(distance);

  if (distance < 10) { // Bin is full
    digitalWrite(BUZZER_PIN, HIGH);
  } else {
    digitalWrite(BUZZER_PIN, LOW);
  }

  // Send distance to IoT platform
  ThingSpeak.setField(1, distance);
  ThingSpeak.writeFields(channelID, writeAPIKey);

  delay(20000); // Update every 20 seconds
}

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Code Explanation

• HC-SR04 ultrasonic sensor measures garbage level by calculating the distance to the top of the bin.
• ESP32 reads distance and sends it to the IoT platform for monitoring.
• A buzzer or LED indicates when the bin is full locally.
• Multiple bins can be monitored simultaneously on the IoT dashboard.

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Advantages

• Reduces manual waste inspection
• Prevents overflowing garbage bins
• Real-time monitoring through IoT
• Scalable for cities, campuses, or industrial areas

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Applications

• Smart cities and municipalities
• Public parks and campuses
• Industrial and corporate waste management
• IoT-enabled sanitation monitoring

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Future Enhancements

• Integrate GPS tracking for mobile garbage collection units
• Add multiple sensors for large bins and smart segregation
• Connect to AI-based predictive dashboards to optimize waste collection routes
• Include solar-powered sensors for energy efficiency

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Conclusion

The Smart Waste Management System is an essential IoT project for modern urban infrastructure. It combines ultrasonic sensors, microcontrollers, and cloud platforms to improve cleanliness, reduce manual effort, and make waste collection efficient and timely.