HC-05 Bluetooth module is an easy-to-use Bluetooth SPP (Serial Port Protocol) module, designed for transparent wireless serial connection setup. The HC-05 Bluetooth Module can be used in a Master or Slave configuration, making it a great solution for wireless communication. This serial port Bluetooth module is fully qualified for Bluetooth V2.0+EDR (Enhanced Data Rate) 3Mbps Modulation with a complete 2.4GHz radio transceiver and baseband. It uses the CSR Bluecore 04 single-chip Bluetooth system with CMOS technology and with AFH (Adaptive Frequency Hopping Feature).

The Bluetooth module HC-05 is a MASTER/SLAVE module (the default factory setting is SLAVE). The Role of the module (Master or Slave) can be configured by sending AT commands. The slave modules cannot initiate a connection to another Bluetooth device but can accept connections. Master modules can initiate a connection to other devices.

The HC-05 Bluetooth module can be used to simply establish a serial port connection between MCU and for example GPS, to a PC or to an embedded system.