Arduino Nano is a small, complete, and breadboard-friendly board based on the ATmega328P (Arduino Nano 3.x).
It does almost all the functions of Uno and has more or less functionalities same as Arduino UNO.
The Nano uses mini-USB for power connection, 6-20V unregulated external power supply (pin 30), or 5V regulated external power supply (pin 27).
The power source is automatically selected to the highest voltage source.
Best used for small projects that need less space and size.
1 / 2 / 3 pcs module without instruction or data sheet