A smartphone-controlled home automation system developed using Arduino Uno, HC-05 Bluetooth Module, and Relay Module for wireless control of electrical appliances.
This project was developed as part of the ECE 6th Semester Major Project (Phase-I) at the Indian Institute of Information Technology (IIIT), Bhopal.
- Project Overview
- Features
- Hardware Components
- Software Requirements
- Working Principle
- Circuit Diagram
- Project Structure
- Arduino Program
- Applications
- Future Improvements
- Team Members
- Supervisor
- License
This project demonstrates a low-cost smart home automation system that enables users to control electrical appliances wirelessly using a smartphone.
The system uses Bluetooth communication between an Android smartphone and an Arduino Uno. Commands sent from the mobile application are received through the HC-05 Bluetooth module and processed by the Arduino, which controls a relay to switch appliances ON or OFF.
- Wireless appliance control
- Smartphone-based operation
- Bluetooth communication
- Arduino Uno based
- HC-05 Bluetooth module
- Relay module switching
- Low-cost implementation
- Easy to build
- Beginner-friendly embedded systems project
| Component | Quantity |
|---|---|
| Arduino Uno | 1 |
| HC-05 Bluetooth Module | 1 |
| Relay Module | 1 |
| AC Bulb | |
| Bulb Holder | |
| Jumper Wires | |
| Power Supply | |
| Smartphone |
 Arduino Uno |
 HC-05 Bluetooth Module |
 Relay Module |
- Arduino IDE
- Bluetooth Terminal App
- Windows 10/11
- USB Cable
The completed hardware prototype of the Smartphone Controlled Home Automation System is shown below.
- User opens the Bluetooth control application.
- Smartphone connects with HC-05 Bluetooth module.
- User presses ON or OFF button.
- Bluetooth module receives the command.
- Arduino reads the command through Serial Communication.
- Arduino switches the relay.
- Relay controls the connected electrical appliance.
The complete wiring diagram for the project is shown below.
Smartphone
│
Bluetooth
│
HC-05 Module
│
Arduino Uno
│
Relay Module
│
Electrical Appliance
| Arduino Uno Pin | Connected To | Description |
|---|---|---|
| 5V | HC-05 VCC | Powers the Bluetooth module |
| GND | HC-05 GND | Common ground |
| TX (D1) | HC-05 RX | Serial communication |
| RX (D0) | HC-05 TX | Serial communication |
| D2 | Relay IN | Controls the relay |
| 5V | Relay VCC | Relay power supply |
| GND | Relay GND | Common ground |
Note: Disconnect the HC-05 module from the Arduino TX/RX pins before uploading the program. Reconnect it after the upload is complete to ensure successful communication.
ON-OFF-System-Arduino-Bluetooth
│
├── Arduino_Code/
│ └── ON_OFF_System.ino
│
├── Circuit_Diagram/
│ ├── Circuit_Diagram.jpg
│ └── Relay_Module_Pin_Diagram.jpg
│
├── Images/
│ ├── Prototype.jpg
│ ├── Arduino_Board.jpg
│ ├── Bluetooth_HC05.jpg
│ ├── Relay_Module.jpg
│ ├── Arduino_IDE_Screenshot.png
│ ├── Bluetooth_Controller_App.png
│ └── Bluetooth_Controller_App_Buttons.jpg
│
├── Presentation/
│ └── Project_Presentation.pptx
│
├── Report/
│ └── Minor_Project_Report.pdf
│
├── LICENSE
├── README.md
└── .gitignore
char value;
void setup()
{
Serial.begin(9600);
pinMode(2, OUTPUT);
}
void loop()
{
if(Serial.available()>0)
{
value=Serial.read();
}
if(value=='1')
{
digitalWrite(2,LOW);
}
else if(value=='0')
{
digitalWrite(2,HIGH);
}
}Complete source code is available inside the Arduino_Code folder.
The Arduino sketch was developed and uploaded using the Arduino IDE.
The project uses an Android Bluetooth Controller application to send ON/OFF commands to the Arduino through the HC-05 Bluetooth module.
 Bluetooth Connection |
 Button Configuration |
- Arduino IDE
- Arduino Uno
- HC-05 Bluetooth Module
- Relay Module
- Jumper Wires
- Android Smartphone with a Bluetooth Controller App
- Clone this repository:
git clone https://github.com/Arpeet-Bhaisare/ON-OFF-System-Arduino-Bluetooth.git- Open the Arduino sketch located in:
Arduino_Code/ON_OFF_System.ino
-
Connect your Arduino Uno to your computer using a USB cable.
-
Select the correct Board and Port in the Arduino IDE.
-
Upload the sketch to the Arduino.
-
Disconnect the USB cable if using an external power supply.
-
Connect the HC-05 Bluetooth module.
-
Pair your smartphone with the HC-05 module (default PIN:
1234or0000). -
Open the Bluetooth Controller App.
-
Press ON or OFF to control the connected appliance.
- Home Automation
- Smart Homes
- Embedded Systems Learning
- Wireless Switching
- College Projects
- Arduino Learning
- IoT Foundation
- Arduino programming
- Serial communication
- Bluetooth communication using HC-05
- Relay control
- Embedded systems fundamentals
- Hardware interfacing
- Smartphone-based device control
- ESP32 Integration
- Wi-Fi Control
- Alexa Support
- Google Home Integration
- Blynk IoT Platform
- Mobile Application Development
- Voice Control
- Cloud Monitoring
This project was developed as part of the ECE 6th Semester Major Project (Phase-I) at the Indian Institute of Information Technology (IIIT), Bhopal.
Supervisor
- Dr. Bhupendra Singh Kirar
- Department of Electronics & Communication Engineering
- Indian Institute of Information Technology (IIIT), Bhopal
Team Members
- Arpeet Bhaisare
- Abhishek Brajvasi
- Srirama Aniketh
- Samarth Varshney
- Arduino Official Documentation
- HC-05 Bluetooth Module Documentation
- Arduino IDE Documentation
- Embedded Systems Laboratory Notes
- Course guidance provided during the ECE 6th Semester Project at IIIT Bhopal
This project is licensed under the MIT License.
See the LICENSE file for details.