#include <Servo.h>

Servo myServo; 
const int servoPin = 3; //pin 3

void setup() {
  myServo.attach(servoPin);  //pin 3 подключаю
}
void loop() {

  myServo.write(0); 
  delay(1000);      
  myServo.write(180);               
  delay(1000);       
}