- Communication status LED
- This module works on 3.3 V. We can connect 5V supply voltage as well since the module has on board 5 to 3.3 V regulators.
- No need for a level shifter
- Operates from 3.3v to 5v max
- Up to 100m range
Key/EN – It is used to bring Bluetooth module in AT commands mode. If Key/EN pin is set to high, then this module will work in command mode. Otherwise, by default, it is in data mode. The default baud rate of HC-05 in command mode is 38400bps and 9600 in data mode.
The HC-05 module has two modes,
- Data mode: Exchange of data between devices.
- Command mode: It uses AT commands which are used to change the setting of HC-05. To send these commands to module serial (USART) port is used.
VCC – Connect 5 V or 3.3 V to this Pin.
GND – Ground Pin of the module.
TXD – Transmit Serial data (wirelessly received data by Bluetooth module transmitted out serially on TXD pin)
RXD – Receive data serially (received data will be transmitted wirelessly by Bluetooth module).
State – It tells whether the module is connected or not.