It is used for writing a sketch to the MCU and serial monitoring by connecting a PC.This also converts USB’s VBUS(5V) to 3.3V by using step-down power circuit and provide VBUS and 3.3V to each leaf.
LED TX
LED which controlled by FT232RQ. Blinks when program is written by UART TX communication.
LED RX
LED which controlled by FT232RQ. Blinks when program is written by UART TX communication.