Arduino - BLUETOOTH Voice And Remote Home Control Android

/*
Author: Danny van den Brande. Arduinosensors.nl. BlueCore Tech.
This code is written for my home voice control app.
The app simply reads the bytes @ case, 1,2,3,etc.
You can control 8 relays trough your phone with this.
You can add any device you want to the relays.
 */
int relay1 = 2;
int relay2 = 3;
int relay3 = 4;
int relay4 = 5;
int relay5 = 6;
int relay6 = 7;
int relay7 = 8;
int relay8 = 9;     
  byte serialA;
void setup()
{
  
  Serial.begin(9600); //Check step 2 of my instructable on how to change your HC-06 modules name and baudrate.
  //my HC-06 has a baudrate set of 9600. Your can be different. But you can change it.
  pinMode(relay1, OUTPUT);
  pinMode(relay2, OUTPUT);
  pinMode(relay3, OUTPUT);
  pinMode(relay4, OUTPUT);
  pinMode(relay5, OUTPUT);
  pinMode(relay6, OUTPUT);
  pinMode(relay7, OUTPUT);
  pinMode(relay8, OUTPUT);
}

void loop() {

if (Serial.available() > 0) {serialA = Serial.read();Serial.println(serialA);}
/*
below are the commands 
 all on / all off
 livingroom on / livingroom off
 kitchen on / kitchen off
 balcony on / balcony off
 bathroom on / bathroom off
 bedroom on / bedroom off
 attic on / attic off
 barn on / barn off
 closet on / closet off
*/   
      switch (serialA) {
    case 1:
      digitalWrite(relay1, HIGH);//livingroom on
      break;
    case 2:
      digitalWrite(relay1, LOW);//livingroom off
      break;
      //
    case 3:
      digitalWrite(relay2, HIGH);//kitchen on
      break;
    case 4:
      digitalWrite(relay2, LOW);//kitchen off
      break;
      //
    case 5:
      digitalWrite(relay3, HIGH);//balcony on
      break;
    case 6:
      digitalWrite(relay3, LOW);//balcony off
      break;
      //
    case 7:
      digitalWrite(relay4, HIGH);//bathroom on
      break;
    case 8:
      digitalWrite(relay4, LOW);//bathroom off
      break;
      //
    case 9:
      digitalWrite(relay5, HIGH);//bedroom on
      break;
    case 10:
      digitalWrite(relay5, LOW);//bedroom off
      break;
      //
    case 11:
      digitalWrite(relay6, HIGH);//attic on
      break;
    case 12:
      digitalWrite(relay6, LOW);//attic off
      break;
      //
    case 13:
      digitalWrite(relay7, HIGH);//barn on
      break;
    case 14:
      digitalWrite(relay7, LOW);//barn off
      break;
      //
    case 15:
      digitalWrite(relay8, HIGH);//closet on
      break;
    case 16:
      digitalWrite(relay8, LOW);//closet off
      break;
      //        
    case 17:
      delay(100);//everything on
      digitalWrite(relay1, HIGH);
      digitalWrite(relay2, HIGH);
      digitalWrite(relay3, HIGH);
      digitalWrite(relay4, HIGH);
      digitalWrite(relay5, HIGH);
      digitalWrite(relay6, HIGH);
      digitalWrite(relay7, HIGH);
      digitalWrite(relay8, HIGH);
      delay(100);
    break;
    case 18://everything off
      digitalWrite(relay1, LOW); 
      digitalWrite(relay2, LOW); 
      digitalWrite(relay3, LOW); 
      digitalWrite(relay4, LOW); 
      digitalWrite(relay5, LOW); 
      digitalWrite(relay6, LOW); 
      digitalWrite(relay7, LOW); 
      digitalWrite(relay8, LOW); 
     default:

      break;
  }

}