Looking for the smallest Atmel microcontroller with built-on motor drivers? The BittyBot MEGABitty microcontroller features an Atmel ATMega8L, motor drivers, and voltage regulation in tidy 0.9" x 0.9" package!
Here's something really cool: A fully-functional, ATMega8L microcontroller board with motor drivers! Well, that in itself isn't new, but here's the kicker - it's only 0.9" x 0.9". It's smaller than it's thumbnail picture here on this webpage!
The original purpose of the MEGABitty was to drive 1 cubic inch-sized robots (tiny robots!), and it does so quite well! But people have been finding that tiny, full-featured microcontrollers are useful in many places. Like as controllers for aerial cameras. Or as compact LED sequencers. Or miniature submersibles. And of course, swarm-bots that communicate to each other. On the flip-side, we've seen them in use as controllers for much larger robots ("HEY! Are all these wires going to that tiny thing in the corner?").
The MEGABitty is a very well proven and solid microcontroller, and besides being the smallest, it's also still quite affordable!
Warning: This kit requires the assembly of extremely small "surface mount" components! Good soldering skills, fine-tip soldering equipment, and sharp eyes are definitely recommended!