LicheePi Nano Docker Expansion Board

This simple expansion board designed for LicheePi
brings out all I/O pins
and adds an independent 3V3 power supply. It also provides multiple additional power pins: 5V, 3V3, and GND.
The independent 3V3 uses an LDO for power, the 5V is directly derived from the USB and shared with the LicheePi Nano, and the 3V3 is derived from the LicheePi Nano's built-in DC-DC converter, resulting in limited power supply capacity.
If peripherals have high power consumption, connect them to an LDO-3V3 or 5V for power.
A reset button is added to avoid the inconvenience of having to repeatedly power on and off to reset.
Three LEDs and three switches are provided, connected to PE4, PE5, and PE6, which can display voltage levels and act as inputs.
The board's width matches that of the core board, allowing it to be soldered regardless of whether the core board has already been soldered with headers.
The board also brings out the USB, with functionality essentially the same as the USB on the core board, except it lacks OTG (meaning no ID cable is connected). Programs can be burned via the expansion board's USB, reducing the use of ports on the core board and extending its lifespan.