DIY Smart Dustbin Project

Have you ever wished your dustbin could open its lid automatically when you come near? In this DIY project, I’ll show you how to build a simple yet effective Smart Dustbin using an Arduino, ultrasonic sensor, and a servo motor.

This is a fun project for beginners and hobbyists that not only makes your home smarter but also teaches you about distance sensing and servo control.

Let’s get started! 👇

Component Required:

• Bucket
• Cardboad
• Servo Motor
• Arduino Uno
• Ultrasonic sensor
• 9v Battery
• Jumper Wire

Circuit Diagram:

Connections:

Component	Arduino Pin
Ultrasonic Trig	D5
Ultrasonic Echo	D6
Servo Signal	D3
LED (+)	D10
LED (-)	GND
Ultrasonic VCC	5V
Ultrasonic GND	GND
Servo VCC	5V
Servo GND	GND

How It Works

• The ultrasonic sensor continuously measures the distance in front of the dustbin.
• If it detects an object (like your hand) within 5 to 30 cm, the Arduino sends a signal to the servo motor to open the lid.
• After 5 seconds, the lid automatically closes.
• An optional LED lights up when the lid is open.

Code:

#include <Servo.h>

Servo servo;

int trigPin = 5;
int echoPin = 6;
int servoPin = 3;
int led = 10;

long duration, dist, aver[3];

bool isOpen = false;
unsigned long openTime = 0;

void setup() {
  Serial.begin(9600);
  servo.attach(servoPin);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(led, OUTPUT);

  closeLid();  // Close lid on power up
}

void measure() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(5);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(15);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH, 30000); // 30ms timeout
  if (duration == 0) {
    dist = 500; // No object detected
  } else {
    dist = (duration / 2) / 29.1;
  }
}

void loop() {
  // Take average of 3 readings
  for (int i = 0; i <= 2; i++) {
    measure();
    aver[i] = dist;
    delay(10);
  }
  dist = (aver[0] + aver[1] + aver[2]) / 3;

  Serial.println(dist);

  // Open only if distance between 5cm and 30cm
  if (dist > 5 && dist < 30 && !isOpen) {
    openLid();
    openTime = millis();
    isOpen = true;
  }

  // Close after 5 seconds
  if (isOpen && (millis() - openTime > 5000)) {
    closeLid();
    isOpen = false;
  }

  delay(100);
}

void openLid() {
  digitalWrite(led, HIGH);
  servo.write(0);  // Adjust angle if needed
}

void closeLid() {
  digitalWrite(led, LOW);
  servo.write(150);  // Adjust angle if needed
}

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