Nano V3.0 ATmega328P 5V 16MHz CH340 microcontroller is a small, complete, microcontroller
board based on the ATmega328 MCU. It has more or less the same functionality as the Arduino
Duemilanove but in a smaller package. It lacks only a DC power jack and uses the more
compact connector instead of a standard USB connector.
It is compatible with Arduino programs and the Arduino IDE. This version of the Nano uses
the CH340G USB interface controller.
It can be powered via the connection, a 6-20V unregulated external power supply (pin 30), or
a 5V regulated external power supply (pin 27). The power source is automatically selected as
the highest voltage source