int stepsPerRevolution = 100;
int stepCount = 0;
int reverse = 0;
int step1s = 8;
int step1d = 7;
int step2s = 11;
int step2d = 12;

void setup() {
  // put your setup code here, to run once:
 pinMode(LED_BUILTIN, OUTPUT);
 pinMode(3, INPUT_PULLUP);
 pinMode(step1s, OUTPUT);
 pinMode(step1d, OUTPUT);
 pinMode(step2s, OUTPUT);
 pinMode(step2d, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  int potentiovalue = analogRead(A1);
  int speed = map(potentiovalue, 0, 1023, 10000, 500);
  if (digitalRead(3) == HIGH) {
    digitalWrite(LED_BUILTIN, HIGH);
    digitalWrite(step1d, HIGH);
    digitalWrite(step2d, HIGH);
  }
  else {
    digitalWrite(LED_BUILTIN, LOW);
    digitalWrite(step1d, LOW);
    digitalWrite(step2d, LOW);
  }
  if (speed < 10000) {
   for(int x = 0; x < stepsPerRevolution; x++)
	 {
		digitalWrite(step1s, HIGH);
    digitalWrite(step2s, HIGH);
		delayMicroseconds(speed);
    digitalWrite(step2s, LOW);
		digitalWrite(step1s, LOW);
		delayMicroseconds(speed);
	 }
  }  
}