Automatic Dustbin Using Arduino UNO, Servo Motor, and Ultrasonic Sensor

Project Overview

An Automatic Dustbin opens its lid automatically when a person brings their hand near the dustbin. The ultrasonic sensor detects the distance, and the servo motor opens or closes the lid accordingly.

Components Required

• 1 × Arduino UNO
• 1 × HC-SR04 Ultrasonic Sensor
• 1 × SG90 Servo Motor
• Jumper Wires
• Breadboard (Optional)
• Dustbin with movable lid
• USB Cable

Circuit Connections

HC-SR04 Ultrasonic Sensor

Servo Motor

Working Principle

1. Ultrasonic sensor continuously measures distance.
2. If distance is less than 20 cm:
   • Servo rotates to 90°.
   • Dustbin lid opens.
3. If distance is greater than 20 cm:
   • Servo returns to 0°.
   • Dustbin lid closes.

Arduino Code

#include <Servo.h>

Servo dustbinServo;

const int trigPin = 9;
const int echoPin = 10;
const int servoPin = 6;

long duration;
int distance;

void setup()
{
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  dustbinServo.attach(servoPin);
  dustbinServo.write(0); // Lid Closed

  Serial.begin(9600);
}

void loop()
{
  // Send ultrasonic pulse
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Read echo
  duration = pulseIn(echoPin, HIGH);

  // Calculate distance
  distance = duration * 0.034 / 2;

  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  if(distance > 0 && distance <= 20)
  {
    dustbinServo.write(90); // Open Lid
    delay(2000);
  }
  else
  {
    dustbinServo.write(0); // Close Lid
  }

  delay(100);
}

Expected Output

Applications

• Smart Dustbin
• Smart Home Automation
• College Mini Project
• IoT & Robotics Demonstration
• Public Hygiene Systems

Future Improvements

• Add LCD to display distance.
• Add buzzer when lid opens.
• Add OLED display.
• Add IoT monitoring using ESP32 and Blynk.
• Add battery-powered operation.