What is a good science exhibition project with Arduino?

One that measures something real and shows it live, such as a distance meter using the speed of sound, a weather station or a plant moisture meter.

Are these projects safe for a school exhibition?

They run from a USB power bank or laptop and use no mains wiring. Charge any battery at home, supervised, and keep water away from the board.

No. The sensors and boards plug into a breadboard with jumper wires.

How do I explain the project to judges?

State the question, show the live reading changing, explain the sensor briefly, show recorded results, and say what you would improve.

8 November 2026 · Soldr

Science exhibition projects with Arduino and ESP32: 8 ideas that teach something

Short answer: the best exhibition projects measure something real and show it live: soil moisture, air pressure, distance, tilt, light, water quality. Below are eight that run from a USB power bank, use parts that plug into a breadboard, and each come with a link that opens Soldr with the build described. Pick one, then explain the science behind the number on the screen.

Judges and visitors remember a project that does something while they watch, and a student who can explain why it works. These ideas are built around one sensor each, so the science is clear. Each lists the sensor, what it teaches, and a ready prompt. All of them stay on low voltage, powered from USB.

1. Plant thirst meter

A capacitive moisture probe in a pot and a small OLED that shows how dry the soil is, with a "water me" message below a threshold. Teaches: how water changes the soil's electrical properties, and why a capacitive probe lasts longer than bare metal.

Open this build on Soldr

2. Mini weather station

A BME280 sensor reading temperature, humidity and air pressure on an OLED. Teaches: how air pressure falls with height (carry it up the stairs and watch), and what relative humidity means.

Open this build on Soldr

3. Speed of sound distance meter

An HC-SR04 ultrasonic sensor showing distance in centimetres. Teaches: echoes and the speed of sound. Distance is half the round-trip time multiplied by the speed of sound, and the sensor's datasheet range is 2 cm to 4 m.

Open this build on Soldr

4. Gravity and tilt meter

An MPU6050 motion sensor showing the tilt angle as you rotate the board. Teaches: an accelerometer measures gravity, about 9.8 m/s² straight down, and the angle comes from how that splits between the axes.

Open this build on Soldr

5. Light and distance experiment

A BH1750 light sensor reading lux as you move a torch closer and further. Teaches: light from a small source spreads out, so the reading drops quickly with distance. Record readings at several distances and plot them.

Open this build on Soldr

6. Water quality comparison

An analog TDS sensor comparing tap water, filtered water and salt water in cups. Teaches: dissolved salts make water conduct electricity, and conductivity gives an estimate of total dissolved solids. Present it as a comparison between samples, not a drinking-water test.

Open this build on Soldr

7. Sun-following panel

Two light sensors either side of a small card "panel" on an SG90 servo, which turns towards the brighter side. Teaches: feedback control, the same idea a real solar tracker uses. Power the servo from its own 5 V supply with a common ground, as the servo maker advises.

Open this build on Soldr

8. Reaction time tester

An LED that lights after a random wait, a button, and an LCD showing your reaction time in milliseconds. Teaches: human reaction time, averages and variation. Collect results from visitors at the stall and show the spread.

Open this build on Soldr

Keeping the stall safe

Power from USB, from a power bank or a laptop. None of these projects needs mains wiring, and none should use it.
No battery charging at the stall. If you use a lithium cell, charge it at home, supervised, never unattended.
Keep water away from the board. In the water and plant projects, only the probe goes in the water or soil; the board and wiring stay dry and to one side.
Tape down loose wires, so visitors' hands don't pull them out.

How to present it

State the question ("Does air pressure change between the ground floor and the roof?").
Show the live reading, and change something so visitors can see it respond.
Explain the sensor in a sentence or two, using the datasheet facts on its reference page.
Show your recorded results: a table or a simple graph.
Say what surprised you, and what you'd improve.

Each link above opens a build with the parts, wiring and code, which you can change before you start. For more ideas aimed at students, see AI-based electronics projects for students in India. If your board doesn't show up when you plug it in, see CH340 and CP210x drivers.

Parts on Compoden: ESP32-DevKitC, Uno R3, capacitive soil moisture sensor, BME280, HC-SR04, BH1750, TDS sensor. Sign in and get 100 credits free.