HC-05 Bluetooth Module Master/Slave

HC-05 module is an easy to use Bluetooth SPP (Serial Port Protocol) module, designed for transparent wireless serial connection setup.

Serial port Bluetooth module is fully qualified Bluetooth V2.0+EDR (Enhanced Data Rate) 3Mbps Modulation with complete 2.4GHz radio transceiver and baseband. It uses CSR Bluecore 04-External single chip Bluetooth system with CMOS technology and with AFH(Adaptive Frequency Hopping Feature).

HC-05 Bluetooth Module Master/Slave
Modify default: change default
Ref. Doc.: AT Command
Schmatic: hc_05_sch.jpg
Sales Price : RM21.10


Bluetooth module HC-05
Operating Supply Voltage+3.6V ~ +5V
VersionBluetooth V2.0 protocol standards
InterfaceUART(3.3V Level) - VCC, GND, TX, RX
ModesMaster or Slave (use AT Command to select)
Default settingSlave mode, baud rate: 9600bps, password: 1234

Pin Definitions

VCCConnect to DC3.6V ~ 5V
GNDConnect to ground
TXDConnect to MCU's RXD (3.3V level)
RXDConnect to MCU's TXD (3.3V level)
KEY(input)Use to set AT command mode('H') or
automatic binding transparent data mode('L')
LED(output)Pairing status indication. 'H' for pairing sucess; 'L' not yet pairing.

On Board LED Indication

1. During power up, set KEY to 'H', LED show slow blinking(1Hz), module go into AT Command mode, default baudrate is 38400bps.

2. During power up, set KEY to 'L' or floating, LED show blinking(2Hz), module is waiting for pairing. If set KEY to 'H', module will go into AT Command mode.

3. After pairing sucess, LED show double blinking(0.5Hz).