#include <Servo.h>Servo myservo; // create servo object to control a servovoid setup() { myservo.attach(D3); // attaches the servo on pin D3 to the servo object}void loop() { int val = analogRead(A0); // reads the value of the potentiometer (value 0-1023) val = map(val, 0, 1023, 0, 180); // scale it to use it with the servo (value between 0 and 180) myservo.write(val); // sets the servo position according to the scaled value delay(15); // waits for the servo to get there}