Bluetooth Controlled Appliances

Bluetooth Controlled Appliances

     Bluetooth Controlled Appliances is another Senior Year Design Project (Thesis) I’ve helped my friends built. Credits to Team Haagen-Dazs for allowing me to share it here.

     This project aims to control typical home appliances like Curtain, Electric Fan and Light Bulb. A computer is used to control them and the device that serves as their bridge of communication is the bluetooth module specifically EGBT 9830 Bluetooth Module. The Graphical User Interface (GUI) is made from Visual Basic 6 using the serial port plugin which is mscomm. The program only transmits single characters for the microcontroller to read. The project uses Half-Duplex Communication.

EGBT 9830 Bluetooth Module

Operating Voltage: 3.3v

     The bluetooth module has visual indicators to show the user if a transmission occured or there’s a problem on the circuitry.

You can use this circuit to provide it a 3.3v power supply.

5 to 3.3v converter

     Under Fig.1 R1 is used to limit the current. Since the current requirement of the Bluetooth Module is 80mA R1 should be in the range of 40-80 ohms or else the bluetooth module will not work.

     The module has CTS and RTS pins and they can be shorted if you want to use them on a beginner level programming. You can of course use the CTS and RTS pins for advance programming since they are flow control signals and it can make your program more stable. It’s TX and RX pins are connected to the RX and TX pins of the micro-controller respectively. The voltage produced by the bluetooth module can be read by the micro-controller so there is no need for an extra circuit between them like Voltage Level Converter.



     The fan is controlled by the micro-controller through triacs. Alternatively you can also use here relays. There are 3 options that the user can choose on how the fan will turn. High is for the faster turning of the fan, Low is for the slower turning of the fan and OFF for shutting down the fan.

Dimming Lights

     Dimming lights refer to the light bulb that varies it’s brightness. The brightness can be adjusted through the visual basic user interface. Options listed are low, medium, high and off. The dimming lights circuit is controlled only by using 1 pin of the microcontroller. I used here Pulse width modulation to vary the bulbs brightness. Using a transistor for switching is very suitable for this kind of application.


     The curtain is controlled by using a stepper motor. The stepper motor involved here is Unipolar. It is drived by a uln2003 Stepper motor driver IC. The curtain is attached to the shaft of the stepper motor which enables it to close and open.

Visual Basic Inteface

Visual Basic Interface


     The software of the project is not that hard to do. Just like my previous Design Project which is the Remote Controlled Surveillance Mobile Robot with IP Cam it uses asynchronous serial communication. The only different thing here is that it uses a bluetooth module, it has a shorter range like about 10m and the address of the bluetooth needs to be set in order for the user to connect to it. For more informations on how to setup the bluetooth module, download the manual on this link. DOWNLOAD MANUAL

     Here is the partial code of the thesis project showing how the bluetooth was enabled and set:

// All program initializations are placed here above

// Bluetooth UART Address Assignment code.
// Bluetooth Requires at least a minimum of 200ms Delay between commands
// in order to relay a response.



//Start Bluetooth Core Code


rest of the codes here

     The program didn’t used any interrupt routines so it is very simple. For questions you can post it here.


22 responses to “Bluetooth Controlled Appliances

  1. hi..would it be possible to make a wireless connection among these devices and can be controlled by using cellular phone with the same technology that is Bluetooth?

  2. Sir lloydi . . can you help me about EGBT – 9830 Interfacing with PIC . . Di ko ma reveal yung Bluetooth may mali po sa code ko siguro .. Gamit ko po Micro C . . Help po please

  3. Hi!

    I am also in process to control electrical appliances through bluetooth. can you tell me how to sent bluetooth commands to controller on BASCOM or any other tool??

  4. Paul, you can use mobile phones to control microcontrollers through bluetooth modules. The challenge is that you have to make a java application to be able to control it.

    I would suggest using laptop computers’ bluetooth to control the microcontroller.


    • Quokka, when I tell them HAVOCK is on the line, they better fkn put me through or it will be look out for RADIO fkn ABC!, I’m a GOD, I’m a Celebrity don’t ya cretins there know..just put me on the line, I promise i will beeauh..trvst me!.

  5. hello sir…..
    can u tell me about visual basic programming for this project…
    how u send command through vb to control fan……. for example???

  6. Sir,
    wishes for the day.

    Here we are trying to control the fan speed through pic controller using bluetooth module.
    here i want to know how can i vary the speed of fan trough pic.

    We are strucked at TRIAC and Optocoupler and PWM programming.
    So please suggest us.


  7. Hey bro, this is Seph Dolido from the Philippines. I would like to know more about your “Bluetooth Controlled Appliances”. I am also a Computer Engineering student. Thank you. Please send me an e-mail,

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