Using Transistors and Driving Motors - Exploring Arduino: Tools and Techniques for Engineering Wizardry - page 90

Summary
In this chapter you learned about the following:
■ DC motors use electromagnetic induction to create mechanical action
from changes in current.
■ Motors are inductive loads that must utilize proper protection and power
circuitry to interface safely with your Arduino.
■ DC motor speed and direction can be controlled with PWM and an H-bridge.
■ Servo motors enable precise positioning and can be controlled using the
Arduino Servo library.
■ A linear regulator can be used to create a secondary 5V supply from a
9V battery.
■ IR distance sensors return analog values representing distances detected
by bouncing infrared light off objects.
■ Code commenting is critical for easing debugging and sharing.