Smart Dustbin with Ultrasonic Sensor and Servo

1/*
2 * Project Name: Smart Dustbin with Ultrasonic Sensor and Servo
3 *
4 * Project Description: 
5 * Build a smart dustbin that opens automatically using an ultrasonic sensor and an Arduino UNO. 
6 * The dustbin lid opens when an object is detected within 20 cm and closes after 3.5 seconds.
7 *
8 * License: GPL3+
9 * This project is licensed under the GNU General Public License v3.0 or later.
10 * You are free to use, modify, and distribute this software under the terms
11 * of the GPL, as long as you preserve the original license and credit the original
12 * author. For more details, see <https://www.gnu.org/licenses/gpl-3.0.en.html>.
13 * 
14 *
15 * Copyright (C) 2024  Ameya Angadi
16 *
17 *
18 * Code Created By: Ameya Angadi
19 * Last Modified On: December 5, 2024
20 * Version: 1.1
21 *
22 */
23
24
25#include <Servo.h>  // Includes the Servo library
26
27Servo servo;
28int trig = 5;       // Pin for triggering the ultrasonic sensor
29int echo = 6;       // Pin for receiving the echo signal
30int servoPin = 9;   // Pin to control the servo motor
31long Duration, Distance, Average;
32long aver[3];       // Array to store distance readings for averaging
33
34void setup() {
35  Serial.begin(9600);
36  servo.attach(servoPin);
37  pinMode(trig, OUTPUT);
38  pinMode(echo, INPUT);
39  servo.write(0);           // Initializes with the lid closed
40  delay(100);
41  servo.detach();           // Detaches servo to save power and avoid jitter
42}
43
44void measure() {
45  digitalWrite(trig, LOW);
46  delayMicroseconds(5);
47  digitalWrite(trig, HIGH);
48  delayMicroseconds(15);
49  digitalWrite(trig, LOW);
50  Duration = pulseIn(echo, HIGH);  // Measures the time taken by the echo
51  Distance = (Duration / 2) / 29.1; // Converts time to distance in centimeters
52}
53
54void loop() {
55  for (int i = 0; i <= 2; i++) { 
56    measure();                  
57    aver[i] = Distance;         // Store each reading for averaging
58    delay(10);
59  }
60  
61  Distance = (aver[0] + aver[1] + aver[2]) / 3; // Calculate average distance
62
63  if (Distance <= 20) {        // Opens the lid if an object is detected within 20 cm
64    servo.attach(servoPin);    
65    servo.write(0);            // Opens the lid
66    delay(3500);               // Keeps the lid open for 3.5 seconds
67    servo.write(180);          // Closes the lid
68    delay(1500);
69    servo.detach();            // Detach to save power
70  }
71}