HC-Series Bluetooth Module Wireless RS232/TTL to UART for Arduino

Wireless Serial Bluetooth Module for Arduino/RPi

The HC-Series Bluetooth Modules are compact, low-power, cost-effective wireless communication devices designed for easy serial communication between microcontrollers and Bluetooth-enabled devices. These modules offer UART (Universal Asynchronous Receiver/Transmitter) interface with support for both 3.3V TTL and RS232 logic levels, making them ideal for wireless communication with Arduino, Raspberry Pi, STM32, AVR, and other embedded systems.

Whether you need master-slave Bluetooth Classic communication, low-energy BLE support, or transparent serial data transmission, the HC-Series has multiple variants to meet diverse wireless communication needs.

Key Features:

• Bluetooth Standard: Bluetooth V2.0+EDR (HC-05/HC-06), Bluetooth 4.0/4.2 (HM-10), BLE 5.0 (HM-18)

• Interface: UART (TX/RX), supports AT commands for configuration

• Baud Rate: Default 9600 bps (configurable via AT commands: 1200 ~ 1382400 bps)

• Operating Voltage: 3.3V logic level (some variants have onboard regulator to support 5V input)

• Communication Range: 5–30 meters (line of sight)

• Antenna: PCB onboard antenna

• Modes: Master / Slave (configurable on certain variants)

• Compatibility: Arduino, STM32, PIC, AVR, ESP32, Raspberry Pi, etc.

• Compact size for breadboard and prototyping use

Common Variants:

1. HC-05

• Bluetooth Version: V2.0+EDR (Bluetooth Classic)

• Mode: Configurable as Master or Slave

• AT Command Mode: Supported (via KEY/EN pin)

• Applications: Full-duplex wireless communication, Arduino to PC/Mobile, robot control

• Range: ~10 meters

2. HC-06

• Bluetooth Version: V2.0+EDR

• Mode: Slave only

• AT Command Mode: Supported (simplified)

• Applications: Simple wireless UART bridge

• Note: Easier to use than HC-05 for slave-only communication

3. HC-05 with Backboard

• Includes onboard voltage regulator (supports 3.6V–6V supply)

• Suitable for Arduino Uno, Nano (5V logic)

• Easy soldering with pin headers

4. HC-06 with Backboard

• Same as HC-06, with onboard 3.3V regulator

• Directly pluggable into Arduino 5V boards

5. HM-10

• Bluetooth Version: BLE 4.0

• Mode: Slave and Master (configurable)

• Low Power: Ideal for battery-powered IoT applications

• iOS and Android Compatible (BLE support)

• AT Commands: Fully supported

• Applications: BLE remote control, smart devices, wearable communication

6. HM-18 / HM-19

• Bluetooth Version: BLE 5.0

• Upgraded version of HM-10 with extended range, faster data rate

• Compatible with latest smartphones and BLE 5.0 features

Typical Applications:

• Wireless programming/debugging of microcontrollers

• Remote sensor monitoring

• Wireless robot control

• Home automation systems

• Serial communication between devices without physical cables

• Wireless data logger and terminal applications

Pinout (Standard 6-Pin Module):