#include <SoftwareSerial.h>   // Include  SoftwareSerial  library
SoftwareSerial BT(10,11);    /*Define pins Rx and Tx on Arduiono, which are connected to Bluetooth.*/

int led1=6;
int led2=5;
char value=0;
 
void setup()
{
  BT.begin(9600);       //Initialize serial port which has been created.
  Serial.begin(9600);   //Initialize serial port.
  pinMode(led1,OUTPUT);
  pinMode(led2,OUTPUT);
}
 
void loop()
{
  if(BT.available())   //If data arrives by BT, it is sent by Serial monitor.
  {
    value=BT.read();    
  }
 
  if(value=='a'){
    digitalWrite(led1,HIGH);
    BT.println("LED1 turn on");
  }
  else if(value=='A'){
    digitalWrite(led1,LOW);
    BT.println("LED1 turn off");
  }
  else if(value=='b'){
    digitalWrite(led2,HIGH);
    BT.println("LED2 turn on");
  }
  else if(value=='B'){
    digitalWrite(led2,LOW);
    BT.println("LED2 turn off");
  }
  value=0;
}