# define CHECK_INTERVAL 50
# define startStopPin 7
# define runningLED   6
# define qPin 5

void setup() {
  Serial.begin(115200);
  Serial.println("HelloWorld!\n");

  pinMode(startStopPin, INPUT_PULLUP);
  pinMode(runningLED, OUTPUT);
}

unsigned long tmrCheck;
bool startStopStatus;
bool previousState = HIGH;
bool running;

void loop() {

  unsigned long currentMillis = millis();

  if (currentMillis - tmrCheck > CHECK_INTERVAL) {

    startStopStatus = digitalRead(startStopPin);

    if (startStopStatus != previousState) {

      if (previousState == HIGH)
        running = !running;
      else
        digitalWrite(qPin, !digitalRead(qPin));



      tmrCheck = currentMillis;
      previousState = startStopStatus;
    }
  }

  digitalWrite(runningLED, running);
}

void loopX() {
  unsigned long currentMillis = millis();

  if (currentMillis - tmrCheck >= CHECK_INTERVAL) {
    // It's time to check the Start/Stop button!
    startStopStatus = digitalRead(startStopPin);
    // Changed? Toggle the "Running" state
    if (startStopStatus != previousState) running = !running;
    // Next check
    tmrCheck = currentMillis;
    previousState = startStopStatus;
  }

  digitalWrite(runningLED, running);
}