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Published August 2, 2025

Smart waste segregation system

Automated waste segregation using Arduino, sensors, and servo motors to sort wet/dry waste, reduce labor, and improve urban sanitation.

IntermediateWork in progress12 hours170

Things used in this project

Hardware components

Arduino UNO

Digilent IR Range Sensor

SG90 Micro-servo motor

Seeed Studio Grove - Capacitive Moisture Sensor (Corrosion Resistant)

SparkFun Ultrasonic Sensor - HC-SR04

LED (generic)

Story

Smart Waste Segregation System

The Problem That Sparked Innovation

Every day, millions of tons of waste are generated, and most of it ends up being thrown into a single bin. Wet food scraps, plastics, metals, and paper all mix together, making recycling inefficient and unhygienic. Manual segregation is time-consuming, unpleasant, and often ignored, leading to overflowing bins, foul smells, and health hazards.

This raised a simple question in our minds:

“What if waste could sort itself?”

That idea became the foundation for our Smart Waste Segregation System.

The Solution: Intelligence Meets Cleanliness

We designed a system that combines simple sensors with automation to separate waste into the right bins without human effort. Instead of depending on awareness or discipline, the system itself takes charge of the process.

The setup consists of:

Hardware Component: Arduino Uno with sensors and actuators.

Software Component: Arduino program that decides, in real time, where the waste should go.

When an item of waste is dropped in, the system instantly checks what type it is, rotates the funnel, and directs it into the right bin — wet, dry, or recyclable.

Technical Architecture: How It All Works

The Brain: Arduino Uno

The Arduino controls the sensors, motors, and decision-making process. Its key inputs and outputs include:

IR Sensor → Detects if waste has been placed.

Moisture Sensor → Differentiates between wet waste (like food scraps) and dry waste (like paper or plastic).

Ultrasonic Sensor → Monitors how full each bin is.

Servo Motor → Rotates the input funnel towards the right bin.

LEDs/Buzzer → Alerts when a bin is nearly full.

The Process Flow

Waste is dropped into the input container.

IR sensor detects the presence of an item.

Moisture sensor checks whether it is wet or dry.

Arduino commands the servo to turn towards the correct bin.

Ultrasonic sensor checks fill level.

LED or buzzer notifies when a bin is nearly full.

State-of-the-Art Features

Automatic Waste Classification

Wet waste vs. dry waste handled instantly.

No human contact required, ensuring hygiene.

Smart Bin Monitoring

Each bin’s level is tracked with an ultrasonic sensor.

Real-time alerts prevent overflow and misuse.

Compact & Portable Design

Can be deployed in homes, offices, or public spaces.

The Development Journey

Phase 1: Understanding the Problem

We realized people often throw everything into one bin out of habit. The insight: automation, not awareness campaigns, could solve this problem at the root.

Phase 2: Hardware Selection

We picked Arduino Uno for its simplicity and wide compatibility. Servo motors were chosen to rotate the funnel, and cheap, reliable sensors were used to keep the system low-cost and accessible.

Phase 3: Building the System

We wired the sensors to Arduino, programmed the logic, and tested various waste samples to fine-tune the classification.

Phase 4: Adding Intelligence

Bin monitoring and alerting were added to make the system more practical for daily use, ensuring bins never overflow silently.

Safety & Reliability Features

Hands-Free Operation: No need to touch or sort waste manually.

Real-Time Alerts: LEDs and buzzers provide instant feedback.

Scalable Design: Can be extended with more bins and classification types.

Building Your Own System

Hardware Requirements:

Arduino Uno

IR Sensor

Moisture Sensor

Ultrasonic Sensor

Servo Motor

LEDs / Buzzer

Li-ion Battery Pack

DIY Bins & Funnel

Software Setup:

Arduino IDE

Libraries for Servo & Ultrasonic sensors

Pre-written logic for classification and bin management

Market Impact and Future Vision

Impact

This system reduces manual effort, promotes recycling, and ensures cleaner public spaces. Municipalities, households, and offices can all benefit from automated segregation.

Future Enhancements

Advanced Sensors: Add color and metal sensors to identify plastic, glass, and metal waste.

IoT Connectivity: Send bin status updates to a central dashboard.

Sustainability: Power the system with solar energy for outdoor use.

AI Integration: Train models to classify waste types more precisely.

Conclusion: Technology Serving the Environment

The Smart Waste Segregation System is more than just an electronics project — it’s a step towards solving one of the biggest urban challenges. By merging low-cost sensors with automation, we’ve shown how technology can make waste management cleaner, smarter, and more efficient.

Every item correctly sorted means:

Less landfill waste

More efficient recycling

A healthier, cleaner community

This project proves that small innovations can make a big environmental impact.

Code

Untitled file

#include <Servo.h>

Servo servo1;

#define IR_PIN 5
#define BUZZER 12
#define MOISTURE_PIN A0
#define TRIG_PIN 2
#define ECHO_PIN 3
#define LED_PIN 13

int soil = 0;
int fsoil = 0;
long duration;
long distance;

void setup() {
  Serial.begin(9600);
  pinMode(IR_PIN, INPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(BUZZER, OUTPUT);
  pinMode(LED_PIN, OUTPUT);

  servo1.attach(7);
  servo1.write(90);
  delay(1000);
}

void loop() {
  fsoil = 0;

  if (digitalRead(IR_PIN) == 0) {
    tone(BUZZER, 1000, 300);
    delay(350);  // wait until tone finishes

    for (int i = 0; i < 3; i++) {
      soil = analogRead(MOISTURE_PIN);
      Serial.print("Raw moisture reading: ");
      Serial.println(soil);
      fsoil += soil;
      delay(75);
    }

    fsoil = fsoil / 3;
    Serial.print("Average moisture reading: ");
    Serial.println(fsoil);

    if (fsoil < 500) {
      Serial.println("Wet waste detected → rotating to 30°");
      servo1.write(30);
    } else {
      Serial.println("Dry waste detected → rotating to 150°");
      servo1.write(150);
    }
    delay(1000);

    Serial.println("Returning to center (90°)");
    servo1.write(90);
    delay(1000);
  }

  // Ultrasonic sensor
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  duration = pulseIn(ECHO_PIN, HIGH);
  distance = duration * 0.034 / 2;
  Serial.print("Bin distance: ");
  Serial.println(distance);

  if (distance < 10) {
    Serial.println("Bin is full! LED ON");
    digitalWrite(LED_PIN, HIGH);
    tone(BUZZER, 2000, 500);
    delay(600);  // ensure tone duration
  } else {
    digitalWrite(LED_PIN, LOW);
  }

  delay(500);
}