How impressive is this? It's how to build what is described as a fully-functional microscope using Arduinos and a Raspberry Pi. There's also LEGO and 3D printing in the mix.

Locomotion is supplied by a Lego Power Function motor controller. He cut an LPF extension wire in half so that he could patch into the PWM signals without altering the motors themselves.

Avoid stepping on these tiny Arduino-compatible boards. MCookies are pricier than the LEGOs they snap into, and will probably cut your feet just as badly.

A Stack Exchange post on a brick’s “clutch power” leads to a 10-day experiment.