Product parameters:
Size: 37.5mm x 15.6mm
Color: Blue
Compatible: HM-10 module
Power supply: 5V power supply or 3.3V power supply.

Specifications:
- Input voltage: 3.3V/5V
- If a 5.0V MCU is used to communicate with the bluetooth module, the 5.0V power port is powered, and the RX TX logic level is 5V.
- If a 3.3V MCU is used to communicate with the bluetooth module, the 3.3V power port is powered, and the RX TX logic level is 3.3V.

Pin:
RX, the serial port receiving end of the bluetooth module is connected to the TXD of the MCU.
TX, the serial port sender of the bluetooth module is connected to the RXD of the MCU.
GND, ground terminal negative
3.3V, 3.3V power supply at the power supply
5V, power supply 5V power supply