[Frank Herrmann] had an interesting idea to turn a geared DC motor into a servo motor assembly ... Together, this handful of parts provide all that is needed to read the encoder, control the ...

That is, you have to pry the servo’s DC motor apart, take its base with brushes out, then insert the encoder disks. Then, you snip and file away at the base’s plastic parts to free up as much ...

Raspberry Pi HATs offer small, stackable data acquisition with features like analog and digital I/O.