#include <Servo.h>
Servo lidServo;
const int trigPin = 9;
const int echoPin = 10;
const int servoPin = 3;
long duration;
int distance;
void setup() {
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
lidServo.attach(servoPin);
lidServo.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 in cm
distance = duration * 0.034 / 2;
Serial.print(“Distance: “);
Serial.print(distance);
Serial.println(” cm”);
// If hand is detected within 15 cm
if (distance > 0 && distance < 15) {
lidServo.write(90); // Open lid
delay(3000); // Keep open for 3 seconds
lidServo.write(0); // Close lid
}
delay(200);
}