void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(2, INPUT_PULLUP);
  pinMode(3, INPUT_PULLUP);
  pinMode(4, INPUT_PULLUP);
  pinMode(A0, INPUT);
  pinMode(13, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(11, OUTPUT);

  //switchcase_display();
}

void loop() {
  // put your main code here, to run repeatedly:
  //ifelse_digital();
  //ifelse_analog();
  //switchcase();
  //whileloop();
  //forloop();
}

void ifelse_digital()
{
  if (digitalRead(2) == LOW)
  {
    digitalWrite(13, HIGH);
  }
  else if (digitalRead(3) == LOW && digitalRead(4) == LOW)
  {
    digitalWrite(12, HIGH);
  }
  else if (digitalRead(2) == LOW && digitalRead(3) == LOW)
  {
    digitalWrite(11, HIGH);
  }
  else
  {
    digitalWrite(13, LOW);
    digitalWrite(12, LOW);
    digitalWrite(11, LOW);
  }
}

void ifelse_analog()
{
  if(analogRead(A0) >= 0 && analogRead(A0) <= 200)
  {
    digitalWrite(13, HIGH);
  }
  else if(analogRead(A0) >= 500 && analogRead(A0) <= 600)
  {
    digitalWrite(12, HIGH);
  }
  else if(analogRead(A0) >= 900 && analogRead(A0) <= 1024)
  {
    digitalWrite(11, HIGH);
  }
  else
  {
    digitalWrite(13, LOW);
    digitalWrite(12, LOW);
    digitalWrite(11, LOW);
  }
}

void switchcase() {
  char val = Serial.read();

  switch (val)
  {
    case 'R':
      digitalWrite(13, HIGH);
      digitalWrite(12, LOW);
      digitalWrite(11, LOW);
      Serial.println("Red LED is turned on.");
    break;
    case 'Y':
      digitalWrite(13, LOW);
      digitalWrite(12, HIGH);
      digitalWrite(11, LOW);
      Serial.println("Yellow LED is turned on.");
    break;
    case 'G':
      digitalWrite(13, LOW);
      digitalWrite(12, LOW);
      digitalWrite(11, HIGH);
      Serial.println("Green LED is turned on.");
    break;
    case 'O':
      digitalWrite(13, LOW);
      digitalWrite(12, LOW);
      digitalWrite(11, LOW);
      Serial.println("All LED is turned off.");
    break;
    default:
      //digitalWrite(13, LOW);
    break;
  }
}

void switchcase_display()
{
  Serial.println("Please type 'R' to turn on Red LED.");
  Serial.println("Please type 'Y' to turn on Yellow LED.");
  Serial.println("Please type 'G' to turn on Green LED.");
  Serial.println("Please type 'O' to turn off all LED.");
}