Introduction to HC-05 Bluetooth Module

The HC-05 Bluetooth module is a versatile component that enables wireless communication with Arduino Uno projects. It offers a simple and cost-effective solution for integrating Bluetooth functionality into your Arduino creations. In this tutorial, we will explore how to set up and use the HC-05 module with the Arduino Uno board.

Setting up Arduino Uno for HC-05 Communication

  • Connect the HC-05 module to the Arduino Uno using jumper wires.
  • Ensure the module is powered correctly by connecting VCC to 5V and GND to GND.
  • Connect the HC-05 module's TX pin to the Arduino's RX pin and RX pin to TX pin.
  • Set the Arduino Uno board to work at 9600 baud rate.

Establishing Bluetooth Communication with HC-05

  • Install a Bluetooth terminal application on your mobile device.
  • Enable Bluetooth on your mobile device and search for available devices.
  • Locate and pair with the HC-05 module by entering the default pairing code (usually "1234" or "0000").
  • Once connected, note the Bluetooth address (MAC address) of the HC-05 module for future use.

Sending and Receiving Data

  • Use the Arduino IDE to upload a simple program to the Arduino Uno board.
  • Write code to initialize the serial communication and configure the HC-05 module.
  • Implement functions to send and receive data between the Arduino Uno and the connected device.
  • Test the communication by sending commands or data from your mobile device to the Arduino Uno and vice versa.

Building an Arduino Uno and HC-05 Project

To showcase the capabilities of the HC-05 module, let's build a simple project—an Arduino-based home automation system. Use the HC-05 module to wirelessly control lights, fans, or other electrical appliances using a smartphone or tablet. You can expand on this idea to create more advanced automation systems.


In this tutorial, we explored the HC-05 Bluetooth module and its integration with the Arduino Uno board. We learned how to establish a Bluetooth connection, send and receive data wirelessly, and build a practical Arduino project. With the HC-05 module, the possibilities for Arduino projects expand significantly, enabling seamless wireless communication. Start experimenting with the HC-05 and Arduino Uno to unlock the full potential of your projects.