스마트 쓰레기통

#include <Servo.h>

Servo lidServo;

const int TRIG = 7;
const int ECHO = 6;
const int SERVO_PIN = 9;
const int LED_PIN = 13;
const int BUZZER = 8;
const int OPEN_DIST = 20;  // 20cm 이내 감지시 열림

void setup() {
  lidServo.attach(SERVO_PIN);
  lidServo.write(0);  // 닫힌 상태
  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  Serial.begin(9600);
}

long getDistance() {
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);
  long duration = pulseIn(ECHO, HIGH, 30000);
  return duration * 0.034 / 2;
}

void openLid() {
  digitalWrite(LED_PIN, HIGH);
  tone(BUZZER, 1000, 100);
  for (int pos = 0; pos <= 90; pos += 3) {
    lidServo.write(pos);
    delay(15);
  }
}

void closeLid() {
  for (int pos = 90; pos >= 0; pos -= 3) {
    lidServo.write(pos);
    delay(15);
  }
  digitalWrite(LED_PIN, LOW);
}

void loop() {
  long dist = getDistance();
  Serial.print("Distance: ");
  Serial.print(dist);
  Serial.println(" cm");

  if (dist > 0 && dist < OPEN_DIST) {
    openLid();
    delay(3000);   // 3초간 열린 상태 유지
    closeLid();
    delay(500);
  }

  delay(100);
}