#include <AccelStepper.h>

int stepsPerRevolution = 6400;
int switchPin = 2;
int dirPin = 5;
int setpPin =6;
int enablePin = 8;

Stepper motor(stepsPerRevolution, dirPin, stePin);

void setup() {
  pinMode(switchPin, INPUT_PULLUP);
  pinMode(enablePin, OUTPUT);
  digitalWrite(enablePin, HIGH);
  motor.setSpeed(1000);
}

void loop() {
  int steps = 6400;
  motor.step(steps);
  delay(500);
  if (digitalRead(switchPin) == LOW) {
    steps = -6400;
    motor.step(steps);
    delay(500);
  }
}