char t;
const int DIR = 12;
const int STEP = 13;
const int REV = 600;
const int DER = 2;
const int STIP = 3;
const int WL = 6;
const int YL = 6;

void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(STEP, OUTPUT);
pinMode(DIR, OUTPUT);
pinMode(STIP, OUTPUT);
pinMode(DER, OUTPUT);
pinMode(WL, OUTPUT);
pinMode(YL, OUTPUT);

Serial.println("Connecting...");
Serial.println("Connected");
}

void loop() {
  // put your main code here, to run repeatedly:
if(Serial.available()){
t = Serial.read();
Serial.println("Processing...");
if(t == 'F'){
Serial.println("Vehicle intiated to move forward");
digitalWrite(DIR, HIGH);
digitalWrite(DER, HIGH);
digitalWrite(WL, LOW);

for(int x = 0;x<REV;x++){
digitalWrite(STEP, HIGH);
digitalWrite(STIP, HIGH);
delayMicroseconds(5000);
digitalWrite(STEP, LOW);
digitalWrite(STIP, LOW);
delayMicroseconds(20);
}
}
else if(t == 'B'){
Serial.println("Vehicle intiated to move backward");
digitalWrite(DIR, LOW);
digitalWrite(DER, LOW);
digitalWrite(WL, LOW);

for(int x = 0;x<REV;x++){
digitalWrite(STEP, HIGH);
digitalWrite(STIP, HIGH);
delayMicroseconds(5000);
digitalWrite(STEP, LOW);
digitalWrite(STIP, LOW);
delayMicroseconds(20);
}
}
delay(100);
}
}