Smart Trash Bin Using Arduino UNO

 

Project Idea

A Smart Trash Bin automatically opens its lid when it detects a person’s hand using an ultrasonic sensor. This helps maintain hygiene and is useful in smart cities, homes, schools, and offices..

🔧 Components Required

1. Arduino UNO

2. Ultrasonic Sensor (HC-SR04)

3. Servo Motor (SG90)

4. Jumper Wires

5. Breadboard

6. Dustbin + Lid (mechanical setup)

7. USB Cable / 5V Power Supply

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⚙️ Working Principle

1. Ultrasonic sensor continuously measures distance.

2. When a hand/object comes within 15 cm, Arduino detects it.

3. Arduino rotates the servo motor to open the dustbin lid.

4. After 3 seconds, the lid closes automatically.

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📐 Circuit Diagram (Connection)

HC-SR04 Ultrasonic Sensor
-------------------------
VCC  → 5V (Arduino)
GND  → GND
TRIG → Digital Pin 9
ECHO → Digital Pin 10

Servo Motor
------------
Red    → 5V
Brown  → GND
Yellow → Digital Pin 6

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💻 Arduino Code (With Comments)

#include <Servo.h>

Servo myServo;

// Ultrasonic sensor pins
int trigPin = 9;
int echoPin = 10;

// Servo pin
int servoPin = 6;

long duration;
int distance;

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

  myServo.attach(servoPin);
  myServo.write(0);   // Lid closed position

  Serial.begin(9600);
}

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

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

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

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

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

  // If object detected within 15 cm
  if (distance > 0 && distance <= 15) {
    myServo.write(90);   // Open lid
    delay(3000);         // Keep open
    myServo.write(0);    // Close lid
  }

  delay(500);
}

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📌 Applications

• Smart homes

• Hospitals

• Schools & colleges

• Public places

• Smart city projects

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📈 Advantages

✔ Touchless operation
✔ Low cost
✔ Easy to build
✔ Hygienic solution