Hello friends, I hope you all are doing great. Today, we will discuss HC-05 Bluetooth Module in detail. We will also study HC-05 Pinout, Datasheet, Features & Projects. HC05 is a Bluetooth module, that works on Serial Protocol ( RX/TX ) for sending and receiving data. We have also designed Bluetooth Library for Proteus, which will help you in simulating this Bluetooth Module in Proteus software.
HC05 Bluetooth Module consists of CSR Bluecore 04 outer single-chip Bluetooth system having CMOS (complementary metal-oxide-semiconductor) technology. This module also fulfils the Bluetooth V2.0+EDR technology. So let's get started with Introduction to HC-05.
HC-05 Pinouts are used for powering up the module and sending/receiving data via Serial Port.
So, let's have a look at HC-05 Pinout, shown in below table:
The purpose of this pinout is to set data value at a high and low level.
At this pinout, the input supply is provided to the module. Its operating voltage is plus five volts.
Serial Transmitting Pin.
Serial Receiving Pin
This Pin is connected to an LED, shows the operating state of the HC-05 Bluetooth module.
Here's the image, where I have labelled HC-05 Pinout:
In the above figure, I have labelled 7. LED, which tells about different states of Bluetooth module:
If it's blinking once in two seconds, it has received a command.
If it's blinking continuously, means the module is waiting for input data.
If it's blinking twice in one second, means it's connected properly.
You can download the HC-05 datasheet by clicking the below button:
HC05 follows the "Bluetooth V2.0+EDR" protocol (EDR stands for Enhanced Data Rate).
Its operating frequency is 2.4 GHz ISM Band.
HC05 uses CSR Bluecore 04-External single-chip Bluetooth system with CMOS technology.
This module follows the IEEE (Institute of Electrical and Electronics Engineers) 802.15.1 standard protocol.
Dimensions of HC-05 are 12.7mmx27mm.
Its operating voltage is 5V.
It sends and receives data by UART, which is also used for setting the baud rate.
it has -80dBm sensitivity.
This module also uses (FHSS), a technique by which a radio signal is sent at different frequency levels.
This module has the ability to work as a master/slave mode.
This module can be easily connected with a laptop or mobile phone via Bluetooth.
HC-05 is normally used in embedded projects, where data needs to be transmitted wirelessly over a small distance.
We can transmit data between two HC-05 modules and can also send data from HC-05 to any Bluetooth appliance i.e. mobile phone, laptop etc.
In order to do so, first of all, we need to power up our HC-05 module, as shown in below figure:
As we push the button connected to Key Pin, it will get LOW & HC-05 will start blinking.
Now, if you check on your mobile phone or laptop, you will be able to find a new Bluetooth device named HC-05.
Once you connected with this device, you will be able to send and receive data in a serial stream manner.
This stream is then processed by a microcontroller (i.e. Arduino UNO) attached with HC-05.
However, do not expect this module to transfer multimedia like photos or songs; you might have to look into the CSR8645 module for that.
HC-05 Arduino Interfacing
HC-05 has 2 working modes:
Data Mode: HC05 sends and receives data via Bluetooth spectrum and then further processes it to Serial Pins.
Command Mode: HC-05 waits for AT (ATtention) commands, acts accordingly & then sends the response in return.
This module uses SPP (Serial Port Protocol) for the transmission of data so it can be easily interfaced with any microcontroller.
For HC-05 Arduino Interfacing:
5V to Vcc Pin.
0V to GND Pin.
RX (receiver) pin of HC-05 with the TX (transmitter) pin of UNO.
TX pin of the HC-05 with the RX pin of UNO.
Now, let's have a look at HC-05 Applications, it can be used in various ways, here I have mentioned few of them:
HC-05 Bluetooth Module is normally used for wireless data transmission among multiple microcontrollers.
It can also be used to communicate between electronic devices like mobile, laptop, computers for data transmission.
It also used in different information and data logging applications.
It's used in robotics for wireless control.
It's used in autonomous projects for collecting data.
So, that was all about the HC05 Bluetooth Module. I have tried my best to explain everything related to this module but if you have any question, ask in the comments. Thanks for reading. Have a good day. :)
I am Syed Zain Nasir, the founder of The Engineering Projects (TEP). I am a
programmer since 2009 before that I just search things, make small projects and now I am sharing my
knowledge through this platform. I also work as a freelancer and did many projects related to
programming and electrical circuitry. My Google Profile+Follow