Description:Power input: DC5V or received by a lithium battery input VBAT and GND.Supports MCU level: 5V / 3.3V for TTL logic(Such as the common 51 and the arduino is 5v. STM32 is the 3.3v)Antenna use: IPEX antenna interfaces, you can use the version PCB antenna or antenna IPEX-SMA- peppersPin Descr..