BLUETOOTH MODULE VOOR ARDUINO 4.0

Input voltage: 3.3V/5V only needs a set of power supply.   
Built in level conversion function.   
If you use MCU 5.0V and Bluetooth module communication, 5.0V power supply port, TX RX logic level 5V   
If you use MCU 3.3V and Bluetooth module communication, 3.3V power supply port, TX RX logic level 3.3V   
RX, Bluetooth module serial receiver and TXD MCU connection.   
TX, Bluetooth module serial port and RXD MCU connection.   
GND, ground terminal