Motion and power
Regulated 5 V supply
Power motors or modules without asking GPIO pins to supply their current.
What it does
A regulated supply maintains voltage within its rated load. Motors draw their largest current at startup and when stalled.
Connections and compatibility
The examples join the external supply’s negative terminal to Uno ground. Motor positive power stays on the external rail; do not join it to the Uno’s USB-fed 5 V rail.
Choosing one
Use an enclosed regulated adapter or USB supply with accessible low-voltage terminals and sufficient current. Check actual motor ratings; 1 A is a starting point for one unloaded micro servo, not a universal guarantee.
Common mistakes
Match voltage and polarity. Loose motor connections and inadequate current capacity cause resets and erratic motion.
Use it in a tutorial
- Servo motors — Move a lightweight pointer with two buttons while powering a micro servo independently of the controller.
- Convert a servo to continuous rotation — Understand a servo conversion, calibrate neutral, and control continuous rotation with a short timed run.
- Stepper motors — Move a 5 V 28BYJ-48 with a ULN2003 driver, starting slowly and accounting for missed steps and backlash.