ULN2003 + 28BYJ-48 Stepper Driver

The cheapest 'real' stepper motor on the planet, driven by a Darlington array — 2,048 micro-steps per revolution.

Difficulty: Through-hole. Estimated build time: about 45 minutes. Estimated parts cost: about US$8.00. 4-part bill of materials with live supplier pricing. The 28BYJ-48 is the bargain-bin stepper motor that everyone learns on — a unipolar 5 V stepper with built-in 64:1 reduction gearing that gives 2,048 steps per output-shaft revolution at full step.