Bluetooth Project : Voice Controlled Led

/*CONTROLLING A LED WITH ARDUINO AND BLUETOOTH MODULE [HC-05]
  THIS CODE DEMONSTRATES CONTROLLING A LED WITH VOICE COMMANDS [GIVEN FROM A MOBILE PHONE].
  
  >> CONNECTIONS [LED TO ARDUINO]:
     |------------|-----------|
     |    LED     |  ARDUINO  |
     |------------+-----------|
     |1)POSITIVE  | PIN 13    |
     |------------+-----------|
     |2)NEGATIVE  | GND       |
     |------------|-----------|

  >> CONNECTIONS [HC-05 TO ARDUINO]:
     |------------|-----------|
     |   HC-05    |  ARDUINO  |
     |------------+-----------|
     |1)POSITIVE  | +5V       |
     |------------+-----------|
     |2)NEGATIVE  | GND       |
     |------------+-----------|
     |3)RX        | TX        |
     |------------+-----------|
     |4)TX        | RX        |
     |------------|-----------|

  NOTE-IT IS ADVISED THAT BLUETOOTH MODULE SHOULD BE ATTACHED TO ARDUINO BOARD AFTER
       UPLOADING CODE TO AVOID ERRORS AND PREVENT POSSIBLE DAMAGE TO BLUETOOTH MODULE.

  CODE CREATED BY - AMEYA ANGADI
  LAST MODIFIED ON - 24/7/2021
  
*/

char input;                    //VARIABLE TO STORE INPUT.
int led1 = 13;                 //DECLARING "led1" PIN FOR A LED.

void setup() {
  Serial.begin(9600);          //STARTS SERIAL MONITOR AT 9600 BAUD RATE.
  pinMode(led1, OUTPUT);       //DEFINING "led1" AS A OUTPUT.
}

void loop() {
  if ( Serial.available())
  {
    input = Serial.read();     //READS THE DATA AND STORES IT AS A VARIABLE.
    Serial.println(input);     //PRINTS THE INPUT.
  }

  if (input == 'X')            //CHECKS WHETER THE RECIEVED VALUE IS EQUAL TO 'X'.
    digitalWrite(led1, HIGH);  //IF VALUE IS EQUAL TO 'X' THEN ARDUINO BOARD SETS "led1" TO HIGH.
  else if (input == 'Y')       //CHECKS WHETER THE RECIEVED VALUE IS EQUAL TO 'Y'.
    digitalWrite(led1, LOW);   //IF VALUE IS EQUAL TO 'Y' THEN ARDUINO BOARD SETS "led1" TO LOW.

  delay(100);
}