HC-05 Bluetooth Module

Bluetooth protocol:  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 ~ +75 Centigrade

Dimension: 26.9mm x 13mm x 2.2 mm

 

HC-05 Technical Specifications

• Serial Bluetooth module for Arduino and other microcontrollers
• Operating Voltage: 4V to 6V (Typically +5V)
• Operating Current: 30mA
• Range: <100m
• Works with Serial communication (USART) and TTL compatible
• Follows IEEE 802.15.1 standardized protocol
• Uses Frequency-Hopping Spread spectrum (FHSS)
• Can operate in Master, Slave or Master/Slave mode
• Can be easily interfaced with Laptop or Mobile phones with Bluetooth
• Supported baud rate: 9600,19200,38400,57600,115200,230400,460800.

HC-05 Equivalent Bluetooth Module

HC-02

Other Bluetooth Modules

HC-04, HC-06, HM-11, ESP32, CSR8645

Where to use HC-05 Bluetooth module

The HC-05 is a very cool module which can add two-way (full-duplex) wireless functionality to your projects and you can also use this module to communicate between two microcontrollers like Arduino or communicate with any device with Bluetooth functionality like a Phone or Laptop. There are many android applications that are already available which makes this process a lot easier. The module communicates with the help of USART at 9600 baud rate hence it is easy to interface with any microcontroller that supports USART. We can also configure the default values of the module by using the command mode. So if you looking for a Wireless module that could transfer data from your computer or mobile phone to microcontroller or vice versa then this module might be the right choice for you.

How to Use the HC-05 Bluetooth module

The HC-05 has two operating modes, one is the Data mode in which it can send and receive data from other Bluetooth devices and the other is the AT Command mode where the default device settings can be changed. We can operate the device in either of these two modes by using the key pin as explained in the pin description.

It is very easy to pair the HC-05 module with microcontrollers because it operates using the Serial Port Protocol (SPP). Simply power the module with +5V and connect the Rx pin of the module to the Tx of MCU and Tx pin of module to Rx of MCU as shown in the figure below

During power up the key pin can be grounded to enter into Command mode, if left free it will by default enter into the data mode. As soon as the module is powered you should be able to discover the Bluetooth device as “HC-05” then connect with it using the default password 1234 and start communicating with it.

Applications

1. Wireless communication between two microcontrollers

2. Communicate with Laptop, Desktops and mobile phones

3. Data Logging application

4. Consumer applications

5. Wireless Robots

6. Home Automation