Bluetooth Controlled Home Automation System Using 8051 Microcontroller

Imagine that you can control the electronic appliances of your home from anywhere inside the house, just using your Smart phone. In this project, we will use wireless Bluetooth technology to control the Home Electronic Appliances through a Android Phone. Bluetooth has a range of 10-15 meters, so that you can switch ON and OFF any electronic appliance within the range. We have also developed a Toy car controlled by Android Phone, using Bluetooth module and Arduino.

 

Here we have used 8051 microcontroller with a Bluetooth module, for wirelessly receive the data, sent from the Android Phone. So that microcontroller can Turn ON and OFF the home appliances accordingly. [Check here more 8051 microcontroller based projects]

 

Main Components

  • 8051 microcontroller
  • Bluetooth Module HC05
  • Relay
  • ULN2003
  • Bulb
  • Holder
  • Wire
  • IC 7805
  • Android phone
  • Bluetooth controller app Android app
  • 10uf capacitor
  • 1000uf capacitor
  • 10K resistor
  • 1k resistor
  • Power Supply

Bluetooth Module:

 HC-05 Bluetooth module consists two things one is Bluetooth serial interface module and a Bluetooth adaptor. Bluetooth serial module is used for converting serial port to Bluetooth.

Bluetooth-Module-HC-05

How to operate Bluetooth module?

You can directly use the Bluetooth module after purchasing from market, because there is no need to change any setting of Bluetooth module. Default baud rate of new Bluetooth module is 9600 bps. You just need to connect rx and tx to controller or serial converter and give 5 volt dc regulated power supply to module.

 

Bluetooth module has two modes one is master mode and second one is slave mode. User can set either mode by using some AT commands. Even user can set module’s setting by using AT command. Here is some commands uses are given:

First of all user need to enter AT mode with 38400 bps baud rate by pressing EN button at Bluetooth module or by giving HIGH level at EN pin. Note: all commands should ends with \r\n (0x0d and 0x0a) or ENTER KEY from keyboard.

After it if you send AT to module then module will respond with OK

AT → Test Command

AT+ROLE=0 → Slave Mode select

AT+ROLE=1 → Master Mode select

AT+NAME=xyz  → Set Bluetooth Name

AT+PSWD=xyz → Set Password

AT+UART=<value1>,<value2>,<value3>  → set Baud rate

Eg. AT+UART=9600,0,0

 

Pin Description of accelerometer:

  1. STATE  → Open
  2. Rx  → Serial receiving pin
  3. Tx  → Serial transmitting pin
  4. GND   → ground
  5. Vcc     → +5volt dc
  6. EN       → to enter in AT mode
  7.  

Working Explanation: 

In this project we have used 8051 microcontroller for controlling the whole process of this project. And a Bluetooth module is used for controlling the home appliances wirelessly. Home appliances will turned ON and OFF when user will touch button in the Bluetooth mobile app in Android mobile phone. To run this project, first we need to download Bluetooth app form Google play store. We can use any Bluetooth app that can send data using Bluetooth. Here are some apps name that can be used:

  1. Bluetooth Spp pro
  2. Bluetooth controller

After installing the App, you need to open it and then search Bluetooth device and select HC-05 Bluetooth device. And then configure keys.

Here in this project we have used Bluetooth controller app.

  1. Download and install Bluetooth Controller.
  2. Turned ON mobile Bluetooth.
  3. Now open Bluetooth controller app
  4. Press scan
  5. Select desired Bluetooth device (Bluetooth Module HC-05).
  6. Now set keys by pressing set buttons on screen

To set keys we need to press ‘set button’ and set key according to picture given below:

Bluetooth controller app for home automation

After setting keys press ok.

You can see in the above picture that there are 9 buttons in which first row is for fan controlling, second one is for light controlling and last one is for TV controlling.  Means First row’s ON and OFF buttons are used to ON and OFF the fan, second row’s buttons are for Light and third ones are for TV. We have used three bulbs of different colors instead of TV and fan, for demonstration purpose.

 

Now, when we touch any button in Bluetooth controller app then Android phone sends a value to Bluetooth module, after receiving this value, Bluetooth module sends the received value to the microcontroller and then microcontroller reads it and compare it with predefined value. If any match is occurred then microcontroller performs relative operation. Same operation will performed each time when button pressed.

Bluetooth Controlled Home Automation Block diagram

Now, when user touch ‘Fan On’ button in Bluetooth controller app then microcontroller receives ‘1’ via Bluetooth module and then controller Switch ‘On’ the Fan by using relay driver and relay. And when user touch ‘Fan Off’ button in Bluetooth controller app then microcontroller receives ‘2’ via Bluetooth module and then controller Switch ‘Off’ the Fan by using relay driver and relay.

Likewise 3,4,5,6 numbers are sent by Android Phone, when Light On, Light Off, TV On, TV Off button has been touched respectively:

Button

Data

Operation

Fan On

1

Fan Turned On

Fan Off

2

Fan Turned Off

Light On

3

Light Turned On

Light Off

4

Light Turned Off

TV On

5

TV Turned On

TV Off

6

TV Turned Off

 

Circuit Diagram and Explanation

Circuit connections of this project are very simple. Bluetooth module’s Rx and Tx pins are directly connected to the  Tx and Rx pins of Microcontroller. Three 5 volt relays are used as a switch for turning On and Off the home appliances running on AC mains. And a relay driver ULN2003 is used for driving relays. Fan, Light and TV are connected at P2.1, P2.2 and P2.3 via relays and relay driver. An 11.0592 MHz Crystal oscillator is used in this circuit for generating clock signal for microcontroller. And a 5 volt voltage regulator LM7805 is used for provide 5 volt for the whole circuit.

Bluetooth Controlled Home Automation System Circuit Diagram

Program Explanation:

In this program, first of all we have included header file and defines input, output pins and variables.

#include<reg51.h>

sbit Fan=P2^0;
sbit Light=P2^1;
sbit TV=P2^2;

 char str;
 char Charin=0;

After this we have created a function for delay.

void delay(int time)
{
  unsigned int i,j;
  for(i=0;i<time;i++)
  for(j=0;j<1275;j++);
}

Here we have some functions that we have used in our program. In this we have configured 9600bps baud rate at 11.0592MHz Crystal Frequency.

void Serialwrite(char byte)
{
  SBUF=byte;
  while(!TI);
  TI=0;
}      
void Serialprintln(char *p)
{
  while(*p)
  {
    Serialwrite(*p);
    p++;
  }
  Serialwrite(0x0d);
}

void Serialbegin()
{
   TMOD=0x20;
   SCON=0x50;
   TH1=0xfd;
   TR1=1;
}

After this, in main program we have initialized UART and monitored the SBUF register for receiving the data. Then data is matched and compared with predefined values and relative operation has been performed.

void main()
{
  P2=0x00;
  Serialbegin();
  Serialprintln("System Ready...");
  delay(50);
  while(1)
  {
    while(!RI);
    Charin=SBUF;
    str=Charin;
    RI=0;
      if(str=='1')
      {
        Fan=1;
        Serialprintln(" Fan ON");
        delay(50);
      }
      else if(str=='2')
      {
        Fan=0;
        Serialprintln(" Fan OFF");
        delay(50);
      }

So that’s how we can create a whole system for the house and can connect all the AC appliances to the 8051 microcontroller using Relays. And this bluetooth controlled home automation system can be operated from a Smart phone.

Code: 

#include<reg51.h>

sbit Fan=P2^0;
sbit Light=P2^1;
sbit TV=P2^2;

 char str;
 char Charin=0;

void delay(int time)
{
 unsigned int i,j;
 for(i=0;i<time;i++)
 for(j=0;j<1275;j++);
}

void Serialwrite(char byte)
{
  SBUF=byte;
  while(!TI);
  TI=0;
}

void Serialprintln(char *p)
{
  while(*p)
  {
    Serialwrite(*p);
    p++;
  }
  Serialwrite(0x0d);
}

void Serialbegin()
{
   TMOD=0x20;
   SCON=0x50;
   TH1=0xfd;
   TR1=1;
}

void main()
{
  P2=0x00;
  Serialbegin();
  Serialprintln("System Ready...");
  delay(50);
  while(1)
  {
    while(!RI);
    Charin=SBUF;
    str=Charin;
    RI=0;
      if(str=='1')
      {
        Fan=1;
        Serialprintln(" Fan ON");
        delay(50);
      }
      else if(str=='2')
      {
        Fan=0;
        Serialprintln(" Fan OFF");
        delay(50);
      }

       else if(str=='3')
      {
        Light=1;
        Serialprintln(" Light ON");
        delay(50);
      }

       else if(str=='4')
      {
        Light=0;
        Serialprintln(" Light OFF");
        delay(50);
      }

       else if(str=='5')
      {
        TV=1;
        Serialprintln(" TV ON");
        delay(50);
      }

       else if(str=='6')
      {
        TV=0;
        Serialprintln(" TV OFF");
        delay(50);
      }
      str=0;
  }
}

Video: 

Comments (67)

  • Pearl's picture
    Pearl

    Please I can't really interpret the circuit diagram and what software did you use for the simulation (was it proteus)

    Feb 05, 2016
  • saddam khan's picture
    saddam khan

    this circuit diagram is draw by using dip trace software.

    and i think it easy to understand. you need to give some of your concentration on the circuit to understand.
    try it again.

    Feb 07, 2016
  • Shah Hussain's picture
    Shah Hussain

    how to use AT commands in program

    Feb 13, 2016
  • ronnie's picture
    ronnie

    Sir what IDE you use for code?

    Feb 24, 2016
  • Abhishek's picture
    Abhishek

    Use Keil IDE.

    Feb 24, 2016
  • ronnie's picture
    ronnie

    sir i'm using egbt-045ms as my bluetooth module. what will be the adjustment?

    Feb 24, 2016
  • ronnie's picture
    ronnie

    Can i usethe same android app. even i'm using egbt-045ms as my bluetooth module?

    Feb 25, 2016
  • aarti's picture
    aarti

    sir plz give me complete information

    Mar 15, 2016
  • Jayant's picture
    Jayant

    All the information is already given.

    Mar 28, 2016
  • eman adel's picture
    eman adel

    please, can i get Code In Assembly language by Keil 8051 Compiler ?

    Apr 04, 2016
  • Azmath's picture
    Azmath

    Sir , what is "R2" in circuit diagram (left side of circuit diagram),
    please explain it.

    Apr 13, 2016
  • Maddy's picture
    Maddy

    R2 is resistor of 10k Ohm

    Apr 18, 2016
  • MOHAMMAD ALI's picture
    MOHAMMAD ALI

    Sir , please provide the code with LCD interface also the modified circuit diagram.

    Apr 23, 2016
  • Namrata's picture
    Namrata

    Is RS232 MAX required for bluetooth interfacing with microcontroller?

    May 16, 2016
  • Maddy's picture
    Maddy

    No

    May 17, 2016
  • Malik Saad's picture
    Malik Saad

    sir i need a help to understand what is TI in the program......if register it is not configured....kindly let me know.

    May 28, 2016
  • Abhishek's picture
    Abhishek

    SBUF (serial buffer special function register) is used for serial communication, whenever we want to send any byte to serial device we put that byte in SBUF register, when the complete byte has been sent then TI bit is set by hardware. We need to reset it for sending next byte. It’s a flag that indicates that byte has been sent successfully. TI is the second bit of SCON register.

    Jul 09, 2016
  • shivam 's picture
    shivam

    Sir whether we require 12v or5v relay ??
    Is there will be no damage by using5v relay??
    Plzz give info in detail I m confused???

    Jun 17, 2016
  • Sumana's picture
    Sumana

    Good project

    Jul 08, 2016
  • zahra modi's picture
    zahra modi

    as bluetooth range is 10-15 meters so if range extension is possible?

    Jul 25, 2016
  • Shivali singh's picture
    Shivali singh

    difference b/w SBUF and str

    Jul 26, 2016
  • Maddy's picture
    Maddy

    SBUF is the 8051's internal Register which is used in Serial Communication where as 'str' is just user defined variable.

    Aug 20, 2016
  • saddam khan's picture
    saddam khan

    yes you may use another bluetooth module with good quality antenna.

    Jul 29, 2016
  • Morinyo's picture
    Morinyo

    Good job

    Jul 30, 2016
  • manoj's picture
    manoj

    i can't understood anything of the circuite diagram.
    please explain the circuite diagram.

    Aug 26, 2016
  • pg's picture
    pg

    is the given code full code?? I dnt think that the given code is working. can u kindly provide me the right o
    ne

    Aug 30, 2016
  • sumangal mistry's picture
    sumangal mistry

    if I change Bluetooth module to extension the rang. then is there program will change?

    Sep 09, 2016
  • sumangal mistry's picture
    sumangal mistry

    if I increase the rang of Bluetooth module up to 100 meter so what I shall I do. pleaze told me sir.

    Sep 18, 2016
  • Maddy's picture
    Maddy

    100 meter is not possible with HC-05 Bluetooth module, better use GSM Based Home Automation, to control the appliances from anywhere.

    Sep 21, 2016
  • pvn's picture
    pvn

    is the given code working or it needs come modification ??
    I need complete code.
    I have tried the abive mentioned code but its not working in proteus. wat can I do to make it work?
    plz help man

    Oct 03, 2016
  • Mitul 's picture
    Mitul

    Can we use atmega32 instead of 8051.Can you give the code and the block diagram.

    Oct 06, 2016
  • sumangal mistry's picture
    sumangal mistry

    if I increase the rang of Bluetooth module up to 100 meter so what I shall I do. pleaze told me sir.

    Oct 07, 2016
  • Maddy's picture
    Maddy

    Your question is already answered above, why are you posting it again and again. Your comment is only visible after getting approved, so you wont be able to see it just after posting.

    Oct 07, 2016
  • ali 's picture
    ali

    can we use arduino instead of micro controller

    Oct 11, 2016
  • omartag's picture
    omartag

    do u have an assembly code for this project?

    Oct 26, 2016
  • prakash 's picture
    prakash

    sir can u help me ,doing bluthooth controlled HA ,but the program is not uploded in targeted MC unit ,i have already chekked that all pheriperal interfaces ande power sources ,i am using friendly board of ours

    Nov 05, 2016
  • Maqsood ali ansari's picture
    Maqsood ali ansari

    SIR, i want to control my load using Gsm, not bluetooth, may it possible.

    Nov 23, 2016
  • monib ahmad's picture
    monib ahmad

    can u plz provide me the code and circuit diagram to control home appliances using arduino and bluetooth module from android mobile..

    Nov 29, 2016
  • uma mahesh's picture
    uma mahesh

    is the above code is assembly language

    Dec 08, 2016
  • Sarmad's picture
    Sarmad

    Hello guys please I need help, I've done everything as mentioned in the article but the issue I am facing is that when I press 0n key from my phone the relay only ticks very low sound as if it is not being magnetised properly to switch on or off inside relay please tell me a solution the signal from microntroller are not enough to energise the relay even though I'm using relay driver

    Dec 18, 2016
  • Abhishek's picture
    Abhishek

    Which Relay are you using? Use 5v Relay.

    Dec 24, 2016
  • sumangal mistry's picture
    sumangal mistry

    sir if I make ISP burner then what I shall do. plz send circuit diagram of AT89C51 ISP burner

    Dec 26, 2016
  • UMA MAHESH BEERAM's picture
    UMA MAHESH BEERAM

    Can you please help me about Bluetooth module

    Jan 21, 2017
  • Jitendra's picture
    Jitendra

    Sir what oscillator is used in circuit for 11.0592 MHz frequency

    Jan 22, 2017
  • VINOD KUMAR MISHRA's picture
    VINOD KUMAR MISHRA

    Dear sir,
    I have degitizer, which is communicate data to PC over comport. I am a software developer and need communication with Android over Bluetooth.
    Can you please provide the circuit to convert from comport to Bluetooth.

    I shall be highly grateful to you.
    Thanking you

    Jan 25, 2017
  • Kirankumar's picture
    Kirankumar

    10uf & 1000uf capacitor voltage??

    Feb 03, 2017
  • sumangal mistry's picture
    sumangal mistry

    sir if I make ISP burner then what I shall do. plz send circuit diagram of AT89C51 ISP burner

    Feb 09, 2017
  • akash's picture
    akash

    Anyone can give me the PCB layout for this circuit

    Feb 12, 2017
  • mousa's picture
    mousa

    what is the type of this language
    is it c or c++ or java or what ?

    Feb 26, 2017
  • Maddy's picture
    Maddy

    Its Embedded C.

    Feb 27, 2017
  • Mahaan's picture
    Mahaan

    Sir in video as shown below relay have u connected IC ULN2003A n if u have connected frm dat have taken one i/p wire r frm relay

    Mar 22, 2017
  • Abhrodeep's picture
    Abhrodeep

    Please Sir reply. Can i use 12Mhz crystal oscillator in this project? is the source code complete?

    Apr 06, 2017
  • Abhishek's picture
    Abhishek

    Source code is complete, you can use 12Mhz crystal but then you need to change the the frequency in Keil uVision software while uploading the code.

    Apr 08, 2017
  • sohil 's picture
    sohil

    sir can we use 8051 development board

    Apr 22, 2017
  • Rustem's picture
    Rustem

    Hi sir. How did u programm this microcontroller? what did u use to programm ? for example phyton chipporog etc..

    May 25, 2017
  • john wick's picture
    john wick

    Sir, could i use the "5V charger or 9V battery through 7805" to supply relays, HC05 and microcontroller instead of using 12V through 7805 ??

    Jun 14, 2017
  • john wick's picture
    john wick

    Sir, could i use the "5V charger or 9V battery through 7805" to supply relays, HC05 and microcontroller instead of using 12V through 7805 ??

    Jun 15, 2017
  • Sam's picture
    Sam

    HI, its a nice project, got scope for lots of applications,
    why are there no header files for bluetooth and usart in the above code.
    could you post it on the wall

    Jun 16, 2017
  • john wick's picture
    john wick

    Sir, what is the function of S1 (in the left hand side of the circuit diagram). Can we skip it ?

    Jun 18, 2017
  • vasky's picture
    vasky

    IS it possible that we can use WiFi instead of Bluetooth to extend its range???

    Jul 09, 2017
  • Hrishikesh's picture
    Hrishikesh

    Sir....I did all the connections properly.......I programmed microcontroller properly.............Then why it's not working............Please reply me.....
    It worked once......

    Aug 12, 2017
  • Asad Abbas's picture
    Asad Abbas

    Good

    Sep 08, 2017

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