HC-05 Bluetooth Module

The HC-05 Bluetooth Module adds convenient wireless serial communication to any microcontroller project, letting your Arduino, Raspberry Pi or similar board talk to laptops and mobile devices over Bluetooth instead of a wired connection. It communicates using the standard Bluetooth Serial Port Profile at a default baud rate of 9600, over USART.

Built around Bluetooth Specification v2.0+EDR operating in the 2.4GHz ISM band with GFSK modulation, the HC-05 offers asynchronous speeds up to 2.1Mbps and supports both authentication and encryption for secure pairing. It runs on a 3.3V supply drawing around 50mA and operates in two modes – Data mode for normal communication and Command mode for changing device settings.

• Profile – Bluetooth Serial Port Profile
• Dimensions – 26.9mm x 13mm x 2.2mm
• Bluetooth protocol – v2.0+EDR
• Frequency – 2.4GHz ISM band
• Modulation – GFSK (Gaussian Frequency Shift Keying)
• Speed – Up to 2.1Mbps async / 160kbps, 1Mbps/1Mbps sync
• Power supply – +3.3V, 50mA
• Security – Authentication and encryption support
• Working temperature – -20°C to +75°C

To connect it, wire the TX and RX pins to your controller and power the module from a 5V pin, keeping in mind its logic level is 3.3V. The HC-05 Bluetooth Module is well suited to wireless robots, data logging, home automation and any embedded project needing simple two-way Bluetooth communication.