The HC-05 is a popular and versatile wireless Bluetooth module used for establishing Bluetooth communication between electronic devices. It is widely used in hobbyist projects, IoT (Internet of Things) applications, robotics, and various other projects that require wireless communication. Here’s a detailed description of the HC-05 wireless Bluetooth module:

Communication Protocol: The HC-05 module is based on Bluetooth technology and uses the Bluetooth Serial Port Profile (SPP) to facilitate serial communication between devices. It allows for transparent serial communication over Bluetooth.
Bluetooth Version: The HC-05 module typically uses Bluetooth version 2.0+EDR (Enhanced Data Rate) and is compatible with devices that support this version or later versions.
Operational Range: The HC-05 module usually operates within a range of approximately 10 meters (33 feet), which is the standard operational range for Bluetooth Class 2 devices.
Interface: The module is easy to interface with microcontrollers, such as Arduino, Raspberry Pi, and other development boards. It typically uses a UART (Universal Asynchronous Receiver/Transmitter) interface for communication with the host device.
Pin Configuration: The module typically has a set of pins for power supply, ground, and communication. Commonly used pins include VCC (power), GND (ground), TX (transmit), RX (receive), EN (enable), and STATE.
Applications: The HC-05 module is used in a variety of applications, including wireless data transmission, remote control systems, wireless sensors, Bluetooth-based home automation, and more.