int pulPin = 8;
int dirPin = 9;
int ledPin = 5;
int stepDelay = 700;
boolean on = false;
int sensor=A7;
int sensorValue=0;
void setup() {
  Serial.begin(115200);
  pinMode(ledPin, OUTPUT);
  pinMode(pulPin, OUTPUT);
  
  digitalWrite(pulPin, LOW);
}
void loop() {
  while (Serial.available()) {
    String cmd = Serial.readStringUntil(';');
    int comma = cmd.indexOf(',');
    String stepVal = cmd.substring(0, comma);
    if (stepVal == "H") {
      on = true;
    }
    else if (stepVal == "J") {
      on = false;
    }
    String stepSpeed = cmd.substring(comma + 1, cmd.length());
    int val=stepSpeed.toInt();
    if (val > 1) {
      stepDelay = stepSpeed.toInt();
      break;
    }
  }
  sensorValue=analogRead(sensor);
  if(sensorValue>300){
  on=false;
  }
  if (on) {
    digitalWrite(pulPin, LOW);
    digitalWrite(ledPin, LOW);
    delayMicroseconds(stepDelay);
    digitalWrite(pulPin, HIGH);
    digitalWrite(ledPin, HIGH);
    delayMicroseconds(stepDelay);
  }
}