Image below shows the pins and other components on a typical HC-05 Bluetooth Module.Īn important point to remember is the HC-05 Bluetooth Module works on a logic level of 3.3V. In my case, the board uses the UART communication.Ĭoming to the pins of the Bluetooth Module, generally, four pins are sufficient for successfully enabling a wireless communication link but the modules produced now-a-days come with six pins namely: VCC, GND, TX, RX, EN and STATE. The HC-05 Module supports for UART, USB as well as SPI communication and depending on the application, necessary pins can be used. The following image shows one such HC-05 Bluetooth Sub Module (the green board mounted on the blue board) being used as a part of a complete Bluetooth Module.

Such Modules come as surface mount board and several third-party manufacturers use these board to build a more complete system with necessary pins and components. Generally, the HC-05 Bluetooth Module, or the HC-05 Sub Module, to be precise, comes with the BC417 IC along with a flash memory. This module is based on BC417 Single Chip Bluetooth IC that is compliant with Bluetooth v2.0 standard and with support for both UART and USB interfaces. HC-05 Bluetooth Module is a simple Wireless Communication device based on the Bluetooth Protocol. If you take a look around the electronics DIY and hobbyists community, HC-05 Bluetooth Module is the device of choice for implementing Bluetooth Communication based projects. So, in this project/tutorial, I will talk a little bit about the HC-05 Module. I have implemented several projects using HC-05 Bluetooth Module like Robotic Arm, Home Automation, LED Matrix etc.īut in all those projects, I have not discussed a lot about the Bluetooth Module, except for what is required to get the project done.

It is one of the most popular and most frequently used low range communication for data transfer, audio systems, handsfree, computer peripherals etc.Ĭoming to usage of Bluetooth Communication in DIY projects, HC-05 Bluetooth Module is the go to device.

Connecting Phone to HC-05 Bluetooth Moduleīluetooth Communication is a 2.4GHz frequency based RF Communication with a range of approximately 10 meters.

Circuit Diagram for Interfacing HC-05 Bluetooth Module with Arduino.

Default Settings of HC-05 Bluetooth Module.

Arduino bluetooth code