HC-05 is a Bluetooth device used for wireless communication with Bluetooth-enabled devices (like smartphones). This module can be used in a master or slave configuration. It communicates with microcontrollers using serial communication (USART). Default settings of the HC-05 Bluetooth module can be changed using certain AT commands.
HC-05 Pinout Configuration
Bluetooth module
| Pin Number | Pin Name | Description |
| 1 | Enable / Key | This pin is used to toggle between Data Mode (set low) and AT command mode (set high). By default it is in Data mode |
| 2 | Vcc | Powers the module. Connect to +5V Supply voltage |
| 3 | Ground | Ground pin of module, connect to system ground. |
| 4 | TX – Transmitter | Transmits Serial Data. Everything received via Bluetooth will be given out by this pin as serial data. |
| 5 | RX – Receiver | Receive Serial Data. Every serial data given to this pin will be broadcasted via Bluetooth |
| 6 | State | The state pin is connected to on board LED, it can be used as feedback to check if Bluetooth is working properly. |
| 7 | LED | Indicates the status of Module
|
| 8 | Button | Used to control the Key/Enable pin to toggle between Data and command Mode |
How to use
The tutorial for interfacing HC-05 module with Arduino can be viewed using this link –
(https://create.arduino.cc/projecthub/electropeak/getting-started-with-hc-05-bluetooth-module-arduino-e0ca81)
Getting Started with HC-05 Bluetooth Module
Common applications
● Microcontroller projects
● Communicate with Laptop, Desktops and mobile phones
● Data Logging application
● Consumer applications
● Wireless Robots
● Industrial control
● Home Automation
Some example tasks that students can try out in the ATL Lab
1. Bluetooth Door Lock –
https://projecthub.arduino.cc/samanfern/c71cd04b-79fd-4d0a-8a4b-b1dacc2f7725
2. Bluetooth Smart Fan –
https://www.robotique.tech/robotics/control-a-fan-with-smartphone-and-arduino/3. Talkative Home Automation –
https://projecthub.arduino.cc/Vishalsoniindia/89896fd1-fef0-4a82-8d33-1f27f8aaccf2?ref=tag&ref_id=hc-05&offset=54. Bluetooth Controlled Car –
https://projecthub.arduino.cc/samanfern/c71cd04b-79fd-4d0a-8a4b-b1dacc2f7725Important Links
1. Additional Extensive Tutorial – (https://howtomechatronics.com/tutorials/arduino/arduino-and-hc-05-bluetooth-module-tutorial/)
Arduino and HC-05 Bluetooth Module Complete Tutorial
2. HC05 Datasheet –
https://components101.com/sites/default/files/component_datasheet3. More Projects using Bluetooth Module –
https://projecthub.arduino.cc/search?value=bluetooth
