Promicro NRF52840 Development board compatible with nice! nano V2.0 with Bluetooth charge management

The default factory built-in program is Blink-All-IO(all IO ports 1S automatically flip), if you need to enter Nice! The Bootloader of Nano V2 should short-circuit the RST to GND twice within 0.5S. Press the RST button twice within 0.5S.