Source: https://mokxi.com/teachers/plans/build-solar-tracker
Updated: 2026-11-11

Lesson plan

# Build a solar tracker lesson plan

Light sensors and servos aim a panel, an INA219 measures it, and a fair experiment compares tracked with fixed.

2 chapters, 3 lessons, about 2 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

- Steer two servos with four light sensors, then read real power off the panel.
- Compare tracked with fixed using measured energy, and nothing else.

### Materials for the whole unit

- Arduino Uno R3
- Current monitor, INA219
- Full-size breadboard
- Hobby servo x 2
- LED x 2
- Light sensor x 4
- Pushbutton
- Resistor x 7
- Solar panel, 6 V 1 W

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 1 h 20 min

## Aim and measure

Steer two servos with four light sensors, then read real power off the panel.

Lesson | Time | What students do

Four eyes and two servos Four light sensors in a cross steer a pan and tilt pair toward the brighter side. How a voltage divider turns light into a number, and how comparing two numbers aims a panel. | 40 min

- Light into numbers
- Left or right
- Up or down
- Calm when balanced

Measure what the panel makes Add a small solar panel, a load and an INA219, and read real volts, milliamps and milliwatts. Why a panel is a current source, and how a shunt measures current. | 40 min

- A panel and a meter
- Full sun
- A cloud goes by
- Night

### Materials

- Arduino Uno R3
- Current monitor, INA219
- Full-size breadboard
- Hobby servo x 2
- Light sensor x 4
- Resistor x 5
- Solar panel, 6 V 1 W

### Check for understanding

Each student finishes "Measure what the panel makes" on their own, without opening the hints. The simulator checks 4 of its 4 steps as they go.

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

Chapter 2. About 40 min

## The experiment

Compare tracked with fixed using measured energy, and nothing else.

Lesson | Time | What students do

Tracked against fixed, honestly Run a fair experiment: twenty seconds tracking, twenty seconds parked, again and again, adding up the energy each way. Only measured numbers, never invented ones. | 40 min

- An experiment, not a claim
- The first window
- Parked
- Read the result

### Materials

- Arduino Uno R3
- Current monitor, INA219
- Full-size breadboard
- Hobby servo x 2
- LED x 2
- Light sensor x 4
- Pushbutton
- Resistor x 7
- Solar panel, 6 V 1 W

### Check for understanding

Each student finishes "Tracked against fixed, honestly" on their own, without opening the hints. The simulator checks 4 of its 4 steps as they go.

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

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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