AT-09 BLE Bluetooth 4.0 Uart Transceiver Module CC2541 Central Switching compatible HM-10
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
3.3V, power supply side 3.3V power supply
5V, power supply side 5V power supply