Unit 2: Making Decisions

Your programs so far have run the same way every time. This unit changes that — you’ll learn to write programs that can choose different paths based on conditions. You’ll also connect your first external component: a push button.

Lessons in This Unit

Lesson Title Key Concepts
Lesson 5 Selection with if and else if, else, comparison operators (==, !=, <, >, <=, >=)
Lesson 6 Buttons and elif elif, push button wiring, active-low inputs, debouncing
Lesson 7 Logical Operators and, or, not, truth tables, complex conditions

New Hardware: Push Buttons

You’ll wire your first external component — a push button. Buttons connect a GPIO pin to GND when pressed, giving you physical input beyond the keyboard.

What You’ll Be Able to Do by the End

  • Write programs that take different actions based on conditions
  • Handle multiple choices with elif
  • Read a physical button and respond to it in code
  • Combine multiple conditions using and, or, and not
  • Build a two-button controller for the NeoPixel

Selection is one of the most important ideas in all of programming. After this unit, your programs can make real decisions — and that changes everything.


Copyright © Paul Baumgarten.