char val;         // Data received from the serial port

const int Ystep_pin = 22; //defining pin connected to step pin of motor driver
const int Ydir_pin = 23; //defining pin connected to direction pin of motor driver
int delayBetweenSteps = 100; //this defines how fast it moves

void setup() {
  Serial.begin(9600); // Start serial communication at 115200 bps

  pinMode(Ystep_pin, OUTPUT); //saying the pin is for output
  pinMode(Ydir_pin, OUTPUT); //saying the pin is for output
}

void loop() {
  while (Serial.available()) {  // If data is available to read,
    val = Serial.read();        // read it and store it in val
  }
  if (val == 'H') {              // If H was received
    digitalWrite(Ydir_pin, HIGH); //Yr_direction pin to be rotate one way 
  } else { //if anything eles
    digitalWrite(Ydir_pin, LOW); //Yr_direction pin to be rotate another way 
  }
  digitalWrite(Ystep_pin, HIGH); //step to hight
  delayMicroseconds(delayBetweenSteps);  //delay between steps
  digitalWrite(Ystep_pin, LOW); // step to low
  delayMicroseconds(delayBetweenSteps);  //delay between steps
  //code avobe saying continue rotating in certain speed
}