Arduino Bluetooth Remote Control (Home Appliances)

Very common Bluetooth Remote control

Programming Arduino Nano  from Arduino UNO 

1). Remove Atmega 328 from Arduino UNO 
2).  Connect Arduino UNO  pin RX to Arduino Nano RX
3).  Connect Arduino UNO  pin TX to Arduino Nano TX
4). Select COM 6 ,as Arduino UNO on COM 6

Simple programming but need to be updated 

#include <SoftwareSerial.h>
SoftwareSerial mySerial(10, 11); //Pin10 RX , Pin 11 TX connected to--> Bluetooth TX,RX
#define relay1 2
#define relay2 3
#define relay3 4
#define relay4 5
char val;
void setup() {
pinMode(relay1,OUTPUT);
pinMode(relay2,OUTPUT);
pinMode(relay3,OUTPUT);
pinMode(relay4,OUTPUT);
digitalWrite(relay1,HIGH);
digitalWrite(relay2,HIGH);
digitalWrite(relay3,HIGH);
digitalWrite(relay4,HIGH);
mySerial.begin(9600);
Serial.begin(9600);
}
void loop() {
//cek data serial from bluetooth android App
if( mySerial.available() >0 ) {
val = mySerial.read();
Serial.println(val);
}
//Relay is on


if( val == '1' ) {
digitalWrite(relay1,LOW); }
else if( val == '2' ) {
digitalWrite(relay2,LOW); }
else if( val == '3' ) {
digitalWrite(relay3,LOW); }
else if( val == '4' ) {
digitalWrite(relay4,LOW); }
//relay all on
else if( val == '9' ) {
digitalWrite(relay1,LOW);
digitalWrite(relay2,LOW);
digitalWrite(relay3,LOW);
digitalWrite(relay4,LOW);
}
//relay is off
else if( val == 'A' ) {
digitalWrite(relay1,HIGH); }
else if( val == 'B' ) {
digitalWrite(relay2,HIGH); }
else if( val == 'C' ) {
digitalWrite(relay3,HIGH); }
else if( val == 'D' ) {
digitalWrite(relay4,HIGH); }
//relay all off
else if( val == 'I' ) {
digitalWrite(relay1,HIGH);
digitalWrite(relay2,HIGH);
digitalWrite(relay3,HIGH);
digitalWrite(relay4,HIGH);
}
}