The HC05 Bluetooth module is a wireless communication module that allows for easy serial communication between two devices over Bluetooth. It is often used in embedded systems, robotics, and other applications where wireless communication is required.

The HC05 module operates at 3.3V and consumes up to 150mA of current during transmission. It supports the Bluetooth 2.0 standard and has a range of up to 10 meters (33 feet) in open space.

The HC05 module can be configured as a master or slave device, allowing it to establish a Bluetooth connection with other devices such as smartphones, tablets, or computers. It communicates using the Serial Port Profile (SPP), which means it can be used to send and receive serial data just like a traditional serial port.

To use the HC05 module, you'll need to connect it to your device using its TX and RX pins. You can then communicate with the module using a UART (universal asynchronous receiver-transmitter) interface.

There are many resources available online that provide detailed instructions on how to set up and use the HC05 Bluetooth module with various microcontrollers and platforms.

This Bluetooth module can be set to be a transmitter or receiver when used with an Arduino. The bluetooth module can also be used to pai with a PC, mobile phone or other device.

More information on how to use this Bluetooth module with an Arduino or other microcontroller is available here:

http://www.martyncurrey.com/arduino-with-hc-05-bluetooth-module-at-mode/

https://arduino-info.wikispaces.com/BlueTooth-HC05-HC06-Modules-How-To