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Bluetooth Controlled Electronic Home Appliances

Bluetooth Controlled Electronic Home Appliances is a simple project, where we can control different electrical appliances and electronic devices using an Android device with the help of Bluetooth Technology.

We have already seen how a DTMF controlled home appliances system works in the earlier post. Operating conventional wall switches is difficult for physically handicapped or elder people. This project provides the solution to this problem by integrating all the electrical appliances to a control unit that can be operated by an Android application on a device (Android smart phone or Tablet).

The proposed system controls the electrical loads based on the data transmitted by the Android device. An Android application should be installed in user’s mobile or tablet to control the electrical loads. Using this Android application user can send the commands to the Bluetooth module to control the electrical loads. Wireless technology used in this project is Bluetooth. It can also be called as “Bluetooth Controlled Electronic Home Appliances” or “Android based Home Automation System” or “Remote Password Operated Electronic Home Appliances Control System”.

[Also Read: How To Make an Adjustable Timer ]

Bluetooth Controlled Electronic Home Appliances Circuit Principle

In this project, a Bluetooth module is interfaced to 8051 Microcontroller. This Bluetooth Module receives the commands from the Android application that is installed on the Android device, using wireless communication (Bluetooth Technology). The program which is written to the 8051 microcontroller communicates with Bluetooth module serially to receive the commands. Microcontroller switches the electrical loads automatically based on the commands received from the Bluetooth.

Android Based Home Automation System Circuit Block Diagram

Bluetooth Controlled Home Electronic Appliances - Block DiagramBluetooth Controlled Electronic Home Appliances Circuit Diagram

Bluetooth Controlled Electronic Home Appliances Circuit Diagram

Components Required

Hardware Requirements

  • 8051 Microcontroller (AT89C51)
  • 8051 Development Board
  • 8051 Programmer (Programming Board)
  • Programming Cable
  • 16 × 2 LCD Display
  • 10KΩ Potentiometer
  • Bluetooth Module (HC – 05)
  • 4 – Channel Relay Module
  • Loads (like Light Bulb, Fan, etc.)
  • Power Supply
  • Connecting wires
  • If 8051 Development Board isn’t available, then you might need the following
    • 10µF Electrolytic Capacitor
    • 2 x 10KΩ Resistors (1/4 Watt)
    • 2 x 33pF Ceramic Disc Capacitors
    • 0592 MHz Quartz Crystal
    • Push Button
    • 1KΩ x 8 Resistor Pack
  • If Relay Module isn’t available, then you can build the 1 – channel relay circuit (for 1 load) using the following
    • 5V or 12V Relay
    • BC547 NPN Transistor
    • 1N4007 PN Junction Diode
    • 1 KΩ Resistor (1/4 Watt)

Software Requirements

  • Keil µVision IDE
  • Willar Software
  • Proteus (for Circuit Diagram and Simulation)
  • Android Application installed on Android Device
Buy Step by step Guide along with Code:Bluetooth Controlled Electronic Home Appliances»

Android Based Home Automation System Circuit Design

This project consists of a microcontroller, 16 x 2 alphanumeric LCD, 4 – Channel Relay Module, Loads (Light Bulbs are used in the demonstration) and Bluetooth Module.

Here, AT89C51 Microcontroller is used. It is an 8 – bit microcontroller and it requires supply voltage of 5V DC. Use 7805 power supply circuit to provide 5V DC to the microcontroller. We can use 9V DC battery or 12V, 1A adapter to provide the supply to the circuit.

For the above circuit additionally you need to connect reset circuit and crystal circuit to the controller to work properly. You can ignore these connections (Power Supply Regulator, Crystal Circuit and Reset Circuit) if you are using an 8051 Development Board.

In the above circuit, the LCD display is used to indicate the status of electrical loads and also used to display received data from Bluetooth (Optional Feature).

Here, the LCD Display is interfaced to the PORT1 of the microcontroller in 8 – bit mode i.e. the data pins of the LCD are connected to PORT1. The three control pins of the LCD i.e. RS, RW and EN are connected to P3.6, GND and P3.7 pins respectively.

Also, a 10KΩ POT is connected to the Contrast Adjust pin of the LCD to control the contrast of the display.

The TX and RX Pins of the Bluetooth Module are connected to the RXD and TXD pins (P3.0 and P3.1) of the microcontroller. VCC pin (Pin 40) is connected to the +5V and GND pin (Pin 20) is connected to ground.

The Microcontroller communicates with Bluetooth Module using serial communication (UART protocol). Use a baud rate of 9600 to communicate with Bluetooth.

If you want to change the Bluetooth name and password then you need to use Bluetooth AT commands.

Below are the few Bluetooth AT commands:

  • AT — Responds OK. (Used to test the Bluetooth module)
  • AT+RESET — Responds OK. (Used to reset the module)
  • AT+NAME? — Responds with the module name.
  • AT+NAME = <name> — Responds OK. Name should be less than or equal to 20 characters.
  • AT+PSWD? — Responds with the existing password.
  • AT+PSWD =<password> — Sets module pairing password.

To know about all the Bluetooth AT commands refer HC-03/05 Embedded Bluetooth Serial Communication Module AT command set.

Electrical loads (like Lamp and DC motor) are connected to the P0.0 to P0.3 Pins through the 4 – Channel Relay Module. Here, relays are used to switch AC loads using small DC voltages. NPN transistors are used to drive the relays.

If you are using a relay module, then transistor and other important components to drive the relay are already embedded on the module itself.

NOTE: The Circuit Diagram shows connections of only one load. But the connections to the other loads can also be made in a similar fashion.

Algorithm for Bluetooth Controlled Electronic Home Appliances

  1. Initialize the LCD and UART protocol.
  2. Now read the data from Bluetooth module.
  3. Display the received data on LCD.
  4. Compare the received string with predefined strings and accordingly switch the electrical loads.
  5. Display the status of electrical loads on LCD.

Android based Home Automation System Circuit Simulation Video

Watch the following output video of home automation system using android applications.


How Bluetooth Controlled Electronic Home Appliances Circuit Works?

  1. Write the program to the project in Keil software and create .hex file.
  2.  Burn program to the controller with help of 8051 Programmer and Willar Software.
  3.  Now, give the connections as per the circuit diagram.
  4. While making the connections, ensure that there is no any common connection between DC and AC supplies.
  5. Use 5V power supply circuit to provide regulated 5V DC to the microcontroller.
  6.  Switch on the both AC and DC supplies.
  7. Now relay output pins gets 230V. So, do not touch the load connected pins.
  8. Install the “Bluetooth Controller” application on your Android Device (Mobile Phone or Tablet) from the following link
  9. Now pair the Android device with Bluetooth module.
  10. Configure the Bluetooth Controller App as per the 8051 Program.
  11. Send data to switch ON or OFF the electrical loads.

Related Post: Also read the post – RF remote control for Home Appliances.

Bluetooth Controlled Electronic Home Appliances Project Output Video

Bluetooth Controlled Electronic Home Appliances Project Applications

  • This project is used to control the various electrical appliances from the remote area.
  • Using this project we can control all the loads using a single remote and a control unit.

Limitations of the Circuit

  • In this project the distance between control unit and android device is limited.

79 Responses

  1. can this bluetooth controlled robot be used in any room with only a single remote control , or some connections have to be made in each different room

  2. thanks for this informative project demonstration i really enjoyed watching it everyday. And i want to do similar project but with more than two appliances, i will like to have the programming code to used as set of reference.

  3. I wan the code because I have similar project.
    My project will control the devices only by clicking on buttons, which will be much easier for old people
    I did not start on the project, just i am collecting information now.

  4. I am doing the same project, using the same IC, for personal use & also am planning to use a relay driver in place of transistor. Can you help me with the C code?

  5. I need the hex file so that I can use the project for my final year project. I am a student of physics with electronics in Lagos State University. I believe that this project will help slot aged people around me.

  6. hello. i need this project code as i believe it will help me figure out what to get the code for my own project working. the project i am making is different from this one. my project requires communication between devices via bluetooth.

  7. I tried ti generate the hex file by using code that you provided. But, it was showing some errors.So, please help out in this.

  8. Send the the android application code and would love to make the project for college mini project banishing the limitation mentioned above

  9. I want to do this project for my mini project in third year. plz if u can guide me for this project ill be helpful.

  10. Sir your project is too good to operate a device from remote location. I have checked and compiled your code on keil and has also simulated it on proteus but the only thing I am confusing about is the android application, can I get that application too sir. I am making this project to learn about the UART communication with more added devices.

  11. Hey ! i m making a project on remote home security system . being amateur i need a little help . it wil be awesome if you could send me the microcontroller code and algorithm or help me in anyway you can as i m not getting any material on internet 🙂

  12. I have made the above hardware for my project…….the code abcd which I’ve typed on Android phn is not being displayed on the LCD ……kindly help…..give suggestions….

  13. hey! in bluetooth controlled home appliances the given project code is wrong .Because wfen i am compiling in zeil compiler erroe has been generated.

  14. Hello!
    My friend and I are interested making this project. We are in third year. As amateurs, we would be glad if you provided the project code to us. Also, can you please say which Bluetooth app need to be downloaded?

  15. sir i interested but i have one problem , i have 89c51 ic , i already install program , but i want to know it is compulsory to connect crystal in circuit, i confuse bcs in your circuit diagram not show crystal and also one question which android app download for this project please sir reply me fast,

  16. Interfacing with lcd not working,when we try to simulate the programme in proteus lcd and loads are not connected .. please help us

  17. can anyone help me to remove this error “ERROR C141 IN LINE 1 OF C:\Keil\C51\BIN\..\INC\uart.h: syntax error near ‘void’ ”

  18. hello sir
    i got an error while compiling bluetooth controlled home appliances the given project code.
    the error is
    uart.h(1): error C141: syntax error near ‘void’
    please help me for correct code
    thank u

  19. I like your video which you have uploaded . I made this project at home. I want programming for PIC16f877a for this project where we can home automation by bluetooth of android.

  20. Hi, i have similar circuit just like yours but the output I place with a kettle. How the schematic circuit would become if the output I use is kettle. I hope you will guide me to build this circuit and i would really appreciate it ;-).

  21. Hello sir i can’t burn program in AT89c51 microcontroller through flash magic.How to burn a program for same or Can i used another microcontroller place it?

    1. There is already a project using Arduino. The title is “How To Make Arduino Based Home Automation Project via Bluetooth?”

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