Skip to content

Modulo Wrap-Around Animation

Run the Modulo Wrap-Around Animation MicroSim Fullscreen

About This MicroSim

A row of 10 pixel circles representing a NeoPixel strip. A "position" counter is shown above.

Learning objective: Understanding - the student can explain why modulo creates wrap-around behavior.

How to Use

Use the on-screen controls - buttons, sliders, dropdowns, and clickable regions - to explore the idea. Every change updates the canvas immediately, so you can predict an outcome and then check it.

Iframe Embed Code

You can place this MicroSim on any web page by adding the following HTML:

<iframe src="https://dmccreary.github.io/moving-rainbow/sims/modulo-wrap-simulation/main.html"
        height="302px"
        width="100%"
        scrolling="no"></iframe>

Lesson Plan

Grade Level

Grades 6-12

Duration

10-15 minutes

Learning Objective

Understanding - the student can explain why modulo creates wrap-around behavior.

Activities

  1. Explore (5 min): Open the MicroSim and try every control. Notice what changes on screen.
  2. Predict (5 min): Before each change, predict what will happen, then test your prediction.
  3. Discuss (5 min): Explain the idea in your own words and connect it to the LED code in Chapter 11.

Assessment

Ask students to describe, in one or two sentences, the relationship the MicroSim demonstrates and how it shows up when programming the LED strip.

References

  1. Chapter 11: Mathematics for LED Programming - the chapter where this MicroSim is used.
  2. Moving Rainbow Intelligent Textbook - the full course this MicroSim belongs to.
  3. MicroSims Reference - the standards behind these interactive simulations.

Original Specification

Full specification used to generate this MicroSim 
Type: interactive-infographic
**sim-id:** modulo-wrap-simulation
**Library:** p5.js
**Status:** Specified

A row of 10 pixel circles representing a NeoPixel strip. A "position" counter is shown above. Controls: a **Step** button advances `pos` by 1, a **Auto** toggle runs it continuously at 5 steps/second. As `pos` increments, the current pixel lights red and the previous one turns off. When `pos` reaches 10 (end of strip), the next step shows the modulo calculation: `10 % 10 = 0` in an overlay, and the first pixel lights up again. Below the strip, the formula `pos = (pos + 1) % 10` is displayed with current values substituted in. Canvas: 700 × 300 px. Responds to window resize.

Learning objective: Understanding — the student can explain why modulo creates wrap-around behavior.