Superliminal Advertising!) 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, actually have two chips. An ATMega16u2 takes ...

Most of us are familiar with the Arduino ... pin layout (Arduino shields likely won’t fit) and more I/Os than the ATmegas have. Sure, it’s not as practical as an actual Arduino Uno, but ...