The HC-05 Bluetooth Module is a low-cost, easy-to-use serial communication module designed for wireless data exchange between microcontrollers and Bluetooth-enabled devices. Operating at 4–6V (typically 5V) with a current of around 30mA, it supports a range of up to 100 meters and complies with the IEEE 802.15.1 Bluetooth standard using Frequency-Hopping Spread Spectrum (FHSS) for reliable transmission. It can function as both Master and Slave, making it suitable for various embedded applications. The module communicates via USART (TTL level) and supports multiple baud rates, allowing seamless interfacing with Arduino boards, laptops, and smartphones for wireless control and data transfer.