#include <Servo.h>
const int Y_pin = A0; 

Servo myservo;  

int val;    

void setup() {
  myservo.attach(7); 
}

void loop() {
  val = analogRead(Y_pin);            
  val = map(val, 0, 1023, 0, 180);     
  myservo.write(val);                  
  delay(15);                           
}