The HC-05 Bluetooth Module is a wireless serial communication module that allows microcontrollers and electronic devices to communicate with Bluetooth-enabled devices. It uses UART serial communication and is commonly used in Arduino projects for wireless data transmission, remote control, and monitoring applications.

Features

• Bluetooth Classic wireless communication

• Supports serial communication through UART

• Can operate in master or slave mode

• Compatible with Arduino and many microcontrollers

• Wireless data exchange with compatible Bluetooth devices

• Compact design with an onboard antenna

• Suitable for robotics and home automation projects

• AT command support for configuration

Specifications

Pin Configuration

Applications

• Arduino wireless communication

• Bluetooth-controlled robots

• Wireless home automation

• Smartphone-controlled electronics

• Wireless sensor data transmission

• Remote switching systems

• Embedded system development

• DIY electronics projects

Advantages

• Eliminates the need for a wired serial connection

• Supports two-way wireless data transmission

• Can communicate with compatible Bluetooth Classic devices

• Easy to integrate with UART-based microcontrollers

• Supports both master and slave configurations

• Suitable for educational and prototyping applications

Package Includes

– 1 × HC-05 Bluetooth Wireless Serial Transceiver Module

Note

The HC-05 module uses 3.3V logic levels. Some breakout boards accept a higher supply voltage through an onboard regulator, but this does not necessarily make the RXD pin 5V-tolerant. Use a suitable logic-level shifter or voltage divider when connecting a 5V microcontroller’s TX pin to RXD. Compatibility with modern smartphones may vary because the HC-05 uses Bluetooth Classic rather than Bluetooth Low Energy (BLE).