The HC05 is a Serial port Bluetooth module which having fully qualified Bluetooth V2.0+EDR (Enhanced Data Rate) 3Mbps Modulation with complete 2.4GHz radio trans receiver 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 is now more popular due to its low price and extremely high features.
This module can be used in Master or Slave Mode and easy switchable between these two modes, By default Slave mode is configured.Modes can be changed using AT Commands.
The slave mode in HC-05 cannot initiate a connection to another Bluetooth device, but can accept connections.Master mode can initiate a connection to other devices.
Here is a very nice tutorial of interfacing the bluetooth module with Android app and Laptop.
In case you are looking at BLE or Bluetooth v4, check this module.
Features of HC-05 Bluetooth Module with Base
- Typical ‐80dBm sensitivity.
- Up to +4dBm RF transmits power.
- Low Power 1.8V Operation, 3.3 to 5 V I/O.
- PIO control.
- UART interface with programmable baud rate.
- With integrated antenna.
- With edge connector.
- Slave default Baud rate: 9600, Data bits:8, Stop bit:1,Parity:No parity
- Auto‐connect to the last device on power as default.
- Permit pairing device to connect as default.
- Auto‐pairing PINCODE:”1234” as default.
- Auto‐reconnect in 30 min when disconnected as a result of beyond therange of connection.
Applications of HC-05 :
- It is used in Electronic projects.
- Bluetooth based Robotic projects using 8051/AVR/PIC/ARM/NXP/Infineon microcontroller.
- It is used in all types of wireless communication purposes.