#include <Servo.h>

const int ser_pin = 11; // Pin for the servo
Servo servo1; // Create a Servo object

void setup() {
  pinMode(12, INPUT); // Set pin 12 as input for motion detection
  servo1.attach(ser_pin); // Attach the servo to pin 11
}

void loop() {
  if (digitalRead(12) == HIGH) { // Check for motion
    for (int pos = 0; pos <= 180; pos++) { // Sweep from 0 to 180
      servo1.write(pos); 
      delay(30); // Wait for the servo to reach the position
    }
    delay(3000); // Wait for 3 seconds
    for (int pos = 180; pos >= 0; pos--) { // Sweep back from 180 to 0
      servo1.write(pos); 
      delay(30); // Wait for the servo to reach the position
    }
  }
}