Finally, the knob on the right could reasonably be thought to be a rotary encoder, but it’s actually connected to a small DC motor.

While there are a couple of open-source brushless drivers already available, [neuromancer2701] created his own brushless motor controller on an Arduino shield.

This Design Idea combines a simple ISA-bus-resident interface circuit; a garden-variety PC; a high-resolution optical shaft encoder; and a PWM-controlled, 0.05-hp, brushed, permanent-magnet dc motor ...

Seeing this Toshiba motor drive, my first thought was ‘what a neat chip for pairing with an Arduino’ as it combines operation across 1.8 to 7V with up to 4A drive – so that is Li-ion batteries, 5V USB ...