stm32连接蓝牙模块，通过外接NFC刷卡的原理图，实现了usb转串口，并同时供电功能。可以外接电池。为dsn格式。- STM32 connect the Bluetooth module, through the external NFC card of the principle diagram, to achieve the USB to the serial port, and at the same time power supply. External battery.