appliance controller using serial port (arduino based )

/*////////////////////////////////////
 //////////Magnatron/////////////////
 ////////////////////////////////////
 ////magnatronelectronics@gmail.com//
 ////////////////////////////////////
 ////////////////////////////////////
 */
int val = 0;       // variable to store the data from the serial port
int serbyte = 0; 
int rlyPin1 = 13;
int rlyPin2 = 12;
int rlyPin3 = 11;
int rlyPin4 = 10;
int ipPin = 14;
int a = 0;


void setup()
{
  pinMode(ipPin,INPUT);
  
  pinMode(rlyPin1,OUTPUT); //Declare relayPINs
  pinMode(rlyPin2,OUTPUT); //Declare relayPINs
  pinMode(rlyPin3,OUTPUT); //Declare relayPINs
  pinMode(rlyPin4,OUTPUT); //Declare relayPINs
  Serial.begin(9600);  
  Serial.println("Magnatron Technologies");
  delay(1000);
  Serial.println("Manu Krishnan 9961868899");
  delay(3000);
  Serial.println("Device Status : Initializing");
  delay(1000);
  Serial.println("System check: ");
  delay(500);
  Serial.println("OK");
  delay(500);
}


void loop () 
{
  a = digitalRead(ipPin);
  if (a == LOW)
  {
    Serial.println("101");
    delay(1000);
   
  }  else
  {
    Serial.println("401");
    delay(1000);
  }
  serbyte = Serial.read();
  if (serbyte != -1)
  {
    val = serbyte;
    switch ( val) 
    {   
    case 'A' :    
    //  Serial.println("device 1 Status : OFF");
      digitalWrite(rlyPin1,LOW);
      break;
    case 'B':    
    //  Serial.println("device 1 Status : ON");
      digitalWrite(rlyPin1,HIGH);
      break;
    case 'C':    
    //  Serial.println("device 2 Status : OFF");
      digitalWrite(rlyPin2,LOW);
      break;  
    case 'D':    
   //   Serial.println("device 2 Status : ON");
      digitalWrite(rlyPin2,HIGH);
      break;
    case 'E':    
     // Serial.println("device 3 Status : OFF");
      digitalWrite(rlyPin3,LOW);
      break;  
    case 'F':    
     // Serial.println("device 3 Status : ON");
      digitalWrite(rlyPin3,HIGH);
      break;
    case 'G':    
      //Serial.println("device 4 Status : OFF");
      digitalWrite(rlyPin4,LOW);
      break;  
    case 'H':    
     // Serial.println("device 4 Status : ON");
      digitalWrite(rlyPin4,HIGH);
      break;   
    case 'Q':
     // Serial.println("device * Status : OFF");
      digitalWrite(rlyPin1,LOW);
      digitalWrite(rlyPin2,LOW);
      digitalWrite(rlyPin3,LOW);
      digitalWrite(rlyPin4,LOW);
      break;
    case 'O':
     // Serial.println("device * Status : ON");
      digitalWrite(rlyPin1,HIGH);
      digitalWrite(rlyPin2,HIGH);
      digitalWrite(rlyPin3,HIGH);
      digitalWrite(rlyPin4,HIGH);
      break;
    case 'T':
      Serial.println("S");
      delay(100);
      Serial.println("101");
      break;
 
    }
  }
}