Bluetooth module HC-05

This is the HC-05 6-pin wireless Bluetooth RF transceiver module, designed for easy serial communication. The module features clearly labeled pins: VCC for connecting the positive power supply, GND for the cathode, RXD for receiving data from other devices, and TXD for sending data to other devices. Additionally, there is an EN pin that allows entry into AT command mode when 3.3V is applied.

The module is extremely versatile and user-friendly. It includes a built-in connection status indicator (LED) that flashes quickly when there is no connection and slowly when it enters AT command mode. It has an on-board 3.3V voltage regulator chip, ensuring stable operation with an input voltage from 3.6V to 6V. It is also protected against reverse polarity. Current consumption is low, at about 30mA when unpaired and only about 10mA after a successful connection.

Compatible with a wide range of microcontrollers, including 51, AVR, PIC, ARM, MSP430, and can even be directly connected to 5V MCUs. It supports the most common communication format: 8 data bits, 1 stop bit, and no parity. The effective transmission distance is up to 10 meters in an open area. After successful pairing, it can be used as a full-duplex serial port without needing to understand any Bluetooth protocol. You can easily switch between host and slave modes and configure parameters like baud rate, pairing password, and device name using AT commands.