// Name:    Choi Ka Ho
// No.:     240021155
// Class:   EG114403/1D
// Program: Ex.3 Q2

int incomingByte = 0;  //variable allowed datatypes: int, char

void setup() {
  Serial.begin(115200);
  Serial.println("No data byte is received!");
  Serial.println("Please input a single digit number:");
}

void loop() {
  if (Serial.available() > 0)
  {                      //read the sensor value 
    incomingByte = Serial.read(); //sensorReading = analogRead(sensorPin)

    switch (incomingByte) {
      case '0': Serial.println("ZERO");
        break;
      case '1': Serial.println("ONE");  // Why a charcter '1' is used as the constant ??
        break;                       //A char is a type that can store only 1 character.
      case '2': Serial.println("TWO");
        break;
      case '3': Serial.println("THREE");
        break;
      case '4': Serial.println("FOUR");
        break;
      case '5': Serial.println("FIVE");
        break;
      case '6': Serial.println("SIX");
        break;
      case '7': Serial.println("SEVEN");
        break;
      case '8': Serial.println("EIGHT");
        break;
      case '9': Serial.println("NINE");
        break;
      default: Serial.println("Invalid data received! Please input a single digit number:");
        break;
    }
  }
}