HC-05 (6 Pin) Specifications

• Bluetooth protocol: Bluetooth Specification v2.0+EDR (Enhanced Data Rate)
• Frequency: 2.4GHz ISM band
• Modulation: GFSK (Gaussian Frequency Shift Keying)
• Emission power: ≤4dBm, Class 2
• Sensitivity: ≤-84dBm at 0.1% BER
• Speed
  • Asynchronous communication: 2.1Mbps (Max) / 160 kbps
  • Synchronous communication: 1Mbps/1Mbps
• Security: Authentication and encryption
• Profiles: Bluetooth serial port
• Supply Voltage: +3.3V to 6.0V
• Supply Current: 30mA
• Working temperature: -20C to +75C
• Dimension: 26.9mm x 13mm x 2.2mm
• HC-05 Bluetooth module follows the IEEE 802.15.1 standardized protocol, through which one can build a wireless Personal Area Network (PAN). It uses frequency-hopping spread spectrum (FHSS) radio technology to send data wirelessly.

HC-05 (6 Pin) Pinout

• KEY/En: This pin is used to bring the Bluetooth module in AT commands mode. By default, this pin operates in data mode. The Key/EN pin should be high to operate Bluetooth in command mode. In HC-05, the default baud speed in command mode is 38400bps and 9600 in data mode.
• VCC: Used to power the Bluetooth module. Connect 5V / 3.3V to this pin.
• GND: The ground pin of the module.
• TXD: Connect this pin with the RXD pin of the microcontroller. This pin transmits Serial data (wireless signals received by the Bluetooth module are converted by module and transmitted out serially on this pin)
• RXD: Connect this pin to the TXD pin of the microcontroller. The HC-05 Bluetooth module receives the data from this pin and then transmits it wirelessly.
• STATE: It is used to check if the module is connected or not. It acts as a status indicator.