Bluetooth Module (HC-05)

Add bluetooth to your project with the HC-05 Bluetooth Module and get access to a simple Rx/Tx pipeline through classic bluetooth protocol. The HC-05 module itself is mounted onto a breakout board which provides easy, breadboard friendly 0.1" headers for Power, Ground, TX, RX, and enable pins. The breakout board also provides a 3.3V regulator so you can power it with 5V from an Arduino or other 5V board.

• Tx/RX Pipeline - The HC-05 is designed to be a transparent TX/RX serial pipeline which allows devices to communicate over serial as they would through a wired connection. The is made possible by the Bluetooth software stack that is onboard the HC-05 module.
• Range - With a range of 30ft (~10m) you can send serial data with ease.
• AT command mode - You can easily enter the AT command mode using the broken out connection to Pin34. NB: Some models have a button instead of a pin, and some have neither - these models have an EN pin. See our tutorial link below for more detail.
• Baud Rate Range - Your HC-05 uses a baud rate of 9600 by default but can go higher. To change it, you'll need to use the relevant AT commands.

Using the HC-05 Module in your project

Getting started with the HC-05 is as simple as connecting it up to your microcontroller, configuring it using simple AT commands, and then pairing it with other Bluetooth devices.

**The HC-05 and HC-06 are 3.3V devices. They have a 5V regulator on board so you can power them with 5V, however, for communication and to use the KEY pin with a 5V board such as an Arduino Uno, you'll need a logic level converter such as our bi-directional logic level converter**

Some HC-05's come with an onboard button which is connected to pin34 of the HC-05 module to enter into AT command mode, whereas others have a pin broken out to the header. We've covered using both versions of the board in our Bluetooth tutorial below.

Our complete guide for using the HC-05 Bluetooth Module.

If you want more, download the The HC-05 Product User Guide for a more detailed overview of this product, technical specifications, pinouts, and examples for use with Arduino, Raspberry Pi and Firewing development boards.

The key differences between the HC-05 and HC-06 Bluetooth Module

The HC-05 can be configured as either a Master or a Slave device, whereas it's brother, the HC-06, can only be used as a Slave device.

Technical Specifications

• Bluetooth protocal: Bluetooth Specification v2.0+EDR
• Frequency: 2.4GHz ISM band
• Modulation: GFSK(Gaussian Frequency Shift Keying)
• Emission power: ≤4dBm, Class 2
• Sensitivity: ≤-84dBm at 0.1% BER
• Speed: Asynchronous: 2.1Mbps(Max) / 160 kbps, Synchronous: 1Mbps/1Mbps
• Security: Authentication and encryption
• Profiles: Bluetooth serial port
• Power supply: +3.3VDC 50mA
• Working temperature: -20 ~ +75Centigrade
• 44mm x 16mm x 7mm