either have a chip capable of USB or rely on a V-USB implementation, the old fogies of the Arduino world, the Uno and Mega ... and use seven I/O pins on this previously overlooked chip.

But what if the Arduino Uno was released in 1980 ... Secondly, it’s simpler: No USB-UART (which also means no USB programming), a different pin layout (Arduino shields likely won’t fit ...

It also has fewer pins than other boards, and its USB port is somewhat ... after eliminating the Uno from your selection, you'll still be left with a wide array of Arduino boards to choose from.

Comparing the Arduino Uno and the Nano ... still three other ways you can power your Nano: via the USB port, VIN pin, and 5V ...