#include <Stepper.h>

const int stepsPer = 200;
Stepper myStepper(stepsPer,8,9,10,11);
const int potPin = A0;

void setup() {
  
  myStepper.setSpeed(60);
}

void loop() {
 
  int potValue = analogRead(potPin);
  int speed = map(potValue, 0, 1023, 10, 100);
  myStepper.setSpeed(speed);
  myStepper.step(stepsPer);
  delay(500);
}