Source: https://mokxi.com/teachers/plans/build-arc-reactor
Updated: 2026-11-11

Lesson plan

# Build an arc reactor and helmet lesson plan

An arc reactor style chest light and a moving faceplate in three builds: the glow, the helmet, then the whole suit.

1 chapter, 3 lessons, about 3 hours, on the Arduino Uno R3. Every lesson runs in the browser, with nothing to install.

Start a class from this course

The unit

## Objectives and materials

### By the end, students can

- Make the reactor glow, give the helmet a faceplate, then run both at once.

### Materials for the whole unit

- Addressable RGB LEDs
- Arduino Uno R3
- Full-size breadboard
- Half breadboard
- Hobby servo
- LED x 2
- Pushbutton
- Resistor x 3
- Touch sensor, TTP223

Every part is already on the simulator’s bench, so there is nothing to buy or hand out. The counts are the most any one lesson uses, if you build it on real breadboards too.

Chapter 1. About 3 h

## Glow, helmet, suit

Make the reactor glow, give the helmet a faceplate, then run both at once.

Lesson | Time | What students do

Make the reactor glow A ring of 16 WS2812 LEDs becomes a chest light that powers up, breathes, spins and holds steady, all on one data wire. | 65 min

- Power it up
- A full ring
- Make it spin
- Hold it steady
- Back to breathing

Open the faceplate A servo lifts the helmet faceplate on a touch or a button press, gliding instead of slamming, while two eyes fade out with PWM. | 50 min

- Eyes on
- Touch to open
- Dark before it lifts
- The gauntlet button

Suit up The chest light and the helmet on one Uno: the reactor breathes while the faceplate glides, the eyes flicker back on and both switches work. | 65 min

- Online
- The glow
- Touch to open
- Eyes out
- Close it with the gauntlet

### Materials

- Addressable RGB LEDs
- Arduino Uno R3
- Full-size breadboard
- Half breadboard
- Hobby servo
- LED x 2
- Pushbutton
- Resistor x 3
- Touch sensor, TTP223

### Check for understanding

Each student finishes "Suit up" on their own, without opening the hints. The simulator checks 5 of its 5 steps as they go.

Then ask each one to explain, in a sentence or two, the last thing it asked of them: "Close it with the gauntlet".

Your class

## Teach this unit as a class

Start a class from this course and its 3 lessons are assigned in one go, in order. Students join with a six-character code or printed login cards, and each one’s work comes back to you.

The class tools are free for 30 days for one class of up to 20 students, with no card. The lessons themselves are free either way.

Start a class from this course See the demo class

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