Bluetooth Controlled Home Automation system with Arduino

We think the Easiest Home automation system is Bluetooth controlled home automation system with Arduino. you can easily make this electronic system. to make this home automation system by yourself you should have basic knowledge of  Arduino, Bluetooth module and relay module. in this article, you can find step by step tutorial how to make Bluetooth Controlled Home Automation system with Arduino.  We have the best electronic projects collection in embedded, IOT, Robotics etc.

Bluetooth Controlled Home Automation system with Arduino

In this era of technology, you have to upgrade yourself with the technology. as we see all industries using now a day a smart way to work with technology like  IOT, Automation. So if you want to Make your home or office automated learn this tutorial Bluetooth controlled home automation system. 

In this project control home appliance by using android phone by Bluetooth connection.  send data through Bluetooth to Bluetooth module which is connected to the Arduino and Arduino send instructions to the relay module . with this module connect home appliance like a bulb, fan etc. It will control with an android mobile phone. we have also a Bluetooth controlled RC car  start tutorial with the component

Components Required for Bluetooth controlled home automation:- 

  • Bluetooth Module HC-05
  • 4 channel relay module
  • Arduino Uno
  • Bulb with Holders
Software Required for Bluetooth controlled home automation:-
  • Arduino Uno
  • Arduino Bluetooth 4CH Android app in the mobile phone
  1. Bluetooth Module HC-05 
Bluetooth Module HC-05 is the most commonly used for Bluetooth data transfer in embedded. it’s having 6 pins in which we require only 4 pins. Rx, Tx, Vcc, Gnd. it is by default slave mode. we can change it’s working from slave to master. we do not require to change its mode. we will use it in slave mode. we have a tutorial if you want to learn about Bluetooth working and connection you can see Bluetooth module HC-05 tutorial

Hardware Features


  • Typical ‐80dBm sensitivity.
  • Up to +4dBm RF transmit power.
  • 3.3 to 5 V I/O.
  • PIO(Programmable Input/Output) control.
  • UART interface with programmable baud rate.
  • With an integrated antenna.
  • With the edge connector.

Software Features

  • Slave default Baud rate: 9600, Data bits:8, Stop bit:1,Parity:No parity.
  • Auto‐connect to the last device on power as default.
  • Permit pairing device to connect as default.
  • Auto‐pairing PINCODE: ”1234″.
       2. Relay module 4 channel 
4 channel relay module
relay module 4 channel having four relays which can operate 4 loads. the relay is an electronic switch which can operate with some voltage, this relay works on 5v volt. and can control the 220v load.
  • Arduino Uno 
Arduino Uno is from the Arduino family. it is an open source microcontroller. very easy to use and capable to interface with most of the sensors. How to use Arduino Uno with the example given  in the last updated post you can learn easily arduino from this article.

How to interface Bluetooth module HC-05 with Arduino


How to connect Bluetooth module HC-05 with Arduino


you can see clearly in this image how to connect relay module 4 channel with Arduino and also you can see Bluetooth connection with the Arduino  



  • Connect Bluetooth Tx with Arduino Pin 10 
  • Connect Bluetooth Rx with Arduino Pin 11 
  • Connect Bluetooth Vcc with Arduino Vcc 
  • Connect Bluetooth Gnd with Arduino Gnd 
  • Connect Arduino 2 with Relay Module IN1
  • Connect Arduino 3 with Relay Module IN2
  •  Connect Arduino 4 with Relay Module IN3
  • Connect Arduino 5 with Relay Module IN4
  • Connect Relay with the load as shown in above Image 



C Code for Bluetooth Controlled Home Automation System With Arduino 


Copy this Code and paste into Arduino IDE. upload code into Arduino Uno. 








#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() {
  Serial.begin(9600); } 
void loop() { 
  //cek data serial from bluetooth android App
  if( mySerial.available() >0 )
  {     val =;
  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);   
   //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); 



How to use android app to control Bluetooth Controlled Home Automation system with Arduino
download Android Bluetooth control app from play store in your phone
Connect Bluetooth With the Bluetooth Module as shown in figure

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