HC-05 TTL Bluetooth Transceiver Module

HC-05 Bluetooth TTL Transceiver Module (with Enable/Disable Button)

The HC-05 Bluetooth TTL Transceiver Module is a versatile and widely used wireless serial communication device designed for seamless data exchange between microcontrollers, computers, and other Bluetooth-enabled devices. Based on the popular HC-05/HC-06 core module, this breakout board provides an easy-to-use serial (UART) interface that allows transparent wireless communication.

The module works as a serial RX/TX data pipe, meaning any serial data transmitted at baud rates from 9600 to 115200 bps can be wirelessly transferred between devices without complex protocol handling. This makes it ideal for replacing wired serial communication in embedded and automation projects.

The remote unit operates on a supply voltage range of 3.3V to 6V, allowing direct battery operation and compatibility with most development boards. All signal pins are 3V–6V tolerant, so external level shifting is typically not required when interfacing with common microcontrollers. However, it should not be connected directly to a standard RS232 serial port. To interface with a computer, an RS232-to-TTL converter or a USB-to-TTL adapter such as an Arduino-compatible USB adapter is required.

The HC-05 module supports both Master and Slave modes, which can be configured using AT commands. This flexibility allows it to either initiate connections (Master mode) or accept connections (Slave mode). In contrast, the HC-06 variant is typically configured as either Master or Slave during firmware customization. The onboard enable/disable (KEY/EN) button simplifies entering AT command mode for configuration and pairing setup.

This module is widely used in embedded systems, industrial automation, robotics, wireless data logging, GPS data transmission, and communication between portable devices and microcontroller-based systems. It is an excellent choice for adding reliable and cost-effective Bluetooth connectivity to Arduino, AVR, PIC, ARM, and other development platforms.