HC-05 Bluetooth Transceiver Slave Module RS232 TTL UART
HC-05 Bluetooth Transceiver Slave Module RS232 TTL UART
HC-05 Wireless Bluetooth Transceiver Slave Module – RS232 / TTL / UART
The HC-05 Wireless Bluetooth Transceiver Slave Module is a compact, reliable serial communication module designed for makers, engineers, and electronics enthusiasts. Whether you're building a DIY Arduino project, designing a custom embedded system, or bridging serial devices wirelessly, this module delivers stable Bluetooth connectivity with easy RS232 / TTL / UART integration.
Key Features
- Bluetooth 2.0 + EDR — reliable short-range wireless serial communication up to ~10 metres
- RS232 / TTL / UART interface — seamlessly connects to microcontrollers, Arduino, Raspberry Pi, and other serial devices
- Slave mode operation — pairs with a Bluetooth master device for straightforward, transparent data transfer
- Wide operating voltage — 3.3 V logic level with onboard 3.3 V regulator (5 V tolerant supply input)
- Configurable via AT commands — easily set baud rate, device name, PIN, and mode to suit your project
- Compact form factor — lightweight PCB design fits neatly into enclosures and breadboards
- Available in 3 colour options — choose the variant that best suits your build
Specifications
- Bluetooth Version: 2.0 + EDR
- Interface: RS232 / TTL UART
- Default Baud Rate: 9600 bps (configurable via AT commands)
- Operating Voltage: 3.3 V (5 V tolerant supply)
- Logic Level: 3.3 V
- Wireless Range: Up to ~10 m (open space)
- Mode: Slave (default)
- Antenna: Onboard PCB antenna
Ideal For
- Arduino, Raspberry Pi & ESP32 wireless serial projects
- Robot control & automation prototyping
- Wireless sensor data logging
- Home automation & IoT builds
- Serial-to-Bluetooth bridge for legacy devices
What's in the Box?
- 1 × HC-05 Bluetooth Transceiver Slave Module
For further information on Bluetooth standards and wireless communication technologies, visit the NIST Bluetooth Security Guide.
Frequently Asked Questions
Q: What is the HC-05 Bluetooth Transceiver Slave Module used for?
A: The HC-05 is a Bluetooth serial communication module that allows microcontrollers and other serial devices to send and receive data wirelessly over Bluetooth. It is widely used in Arduino, Raspberry Pi, and other embedded electronics projects that require a wireless RS232 / TTL / UART connection.
Q: How do I connect the HC-05 module to an Arduino?
A: Connect the HC-05's TX pin to the Arduino's RX pin and the HC-05's RX pin to the Arduino's TX pin. Power the module with 3.3 V–5 V (VCC) and connect GND. Upload a serial sketch to the Arduino, then pair your smartphone or Bluetooth master device with the HC-05 (default PIN: 1234) to begin wireless serial communication.
Q: Can I configure the HC-05 module's baud rate and device name?
A: Yes. The HC-05 supports AT command mode, which lets you change the baud rate, device name, pairing PIN, and operating mode. Enter AT command mode by holding the onboard button while powering on the module, then send AT commands via a serial terminal at 38400 bps.
Q: Is the HC-05 module compatible with both Android and iOS devices?
A: The HC-05 uses Bluetooth Classic (2.0 + EDR), which is fully supported by Android devices. Most modern iOS devices prioritise Bluetooth Low Energy (BLE) and may have limited support for Bluetooth Classic serial profiles — a BLE module (such as HC-08 or HM-10) may be preferable for iOS-based projects.