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.
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.
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 servosFour 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 |
|
| Measure what the panel makesAdd 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 |
|
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".
The experiment
Compare tracked with fixed using measured energy, and nothing else.
| Lesson | Time | What students do |
|---|---|---|
| Tracked against fixed, honestlyRun 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 |
|
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".
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.