Arduino science fair project ideas with a real hypothesis
- 192parts on the bench
- 25boards running now
- 1.00xreal time, on every board
A science fair project is an experiment, not a gadget. Judges want a question, a hypothesis you can test, one thing you change on purpose (the independent variable), one thing you measure (the dependent variable) and the things you keep the same. An Arduino is a great way to measure consistently, but the measuring has to be in service of a question.
Every idea below is written that way. Five have a finished circuit you can open and run now. The rest name a starting circuit to build from. Each idea is also labeled honestly: some produce valid data inside the simulator, and some need real hardware, because a simulated sensor reports what the model says and not what your kitchen or your backyard is actually doing.
Three labels are used. Valid in the simulator: the data comes from a person or from the circuit itself. Practice in the simulator: build and debug here, then collect the real data on hardware. And a note wherever the rules for testing people apply.
Reaction time (ready to run)
1. Does reaction time improve with practice? Change: trial block (1 to 5). Measure: milliseconds from lamp to press. Valid in the simulator, because the data comes from you.
2. Is your dominant hand faster? Change: hand. Measure: mean reaction time over 20 trials each. Valid in the simulator.
3. Does background music slow you down? Change: silence, music without words, music with words. Measure: reaction time. Valid in the simulator.
4. Are you faster in the morning or the evening? Change: time of day. Measure: reaction time. Valid in the simulator.
The reaction time project page has the full procedure, a data table and how to get your numbers out as a CSV file. Any of these that measures people, you included, counts as human participant research (see the rules section below).
Two players (ready to run)
5. Does competing against someone make you react faster? Change: playing alone or against a partner. Measure: reaction time. Valid in the simulator, human participant rules apply.
6. Does the winner of the first round keep winning? Change: nothing; count streaks over 30 rounds. Measure: how often the first winner wins the next round. Valid in the simulator.
Circuits themselves (ready to run)
7. How does resistance change how long a capacitor takes to charge? Change: R. Measure: time to 63 percent on the scope. Valid in the simulator as a test of the theory; repeat with real parts to compare.
8. Does a 555 blinker follow its formula? Change: the capacitor. Measure: frequency. Valid in the simulator; the 555 on the bench circuit has the scope and meter already on it.
9. Which wastes less battery, lamps in series or in parallel? Change: wiring. Measure: supply current and brightness. Valid in the simulator.
10. How much does a meter change what it measures? Change: resistor size. Measure: the error. Valid in the simulator (set 10 of the Circuit Lab practice test).
11. How does an LED’s current change with its series resistor? Change: resistor. Measure: current. Valid in the simulator, then compare a real LED.
12. How well does an RC filter block high frequencies? Change: frequency. Measure: output amplitude. Valid in the simulator; start from the RC filter on the scope project.
Temperature and light (ready to run, real data needs hardware)
13. Which cup keeps a drink warm longest: paper, foam or insulated steel? Change: cup. Measure: temperature every minute with a TMP36. Practice in the simulator.
14. Does a car parked in the sun get hotter with the windows cracked? Change: window gap. Measure: temperature. Practice in the simulator; ask an adult to help and never sit in a hot car.
15. Which room in your home gets the most daylight? Change: room. Measure: LDR reading every ten minutes. Practice in the simulator.
16. Does a white roof sample stay cooler than a black one? Change: color. Measure: temperature under a lamp. Practice in the simulator.
17. How fast does a bathroom’s humidity drop after a shower with the fan on or off? Change: fan. Measure: humidity with a DHT22 (start from the weather station circuit). Practice in the simulator.
18. Does a thermistor or a TMP36 respond faster to a temperature change? Change: sensor. Measure: time to settle. Practice in the simulator.
Distance and motion (ready to run, real data needs hardware)
19. How accurate is an ultrasonic sensor at different distances? Change: distance to a wall. Measure: error against a tape measure. Practice in the simulator.
20. Do soft surfaces fool an ultrasonic sensor? Change: surface (wall, pillow, curtain). Measure: reading error. Needs hardware; the simulated sensor has no surfaces.
21. Does a sensor read differently at an angle? Change: angle. Measure: reading. Needs hardware.
22. How often is a hallway used? Change: time of day. Measure: PIR motion counts. Practice in the simulator.
23. How long does the fridge door stay open per day? Change: day of week. Measure: reed switch open time. Practice in the simulator.
24. Can a tilt sensor measure the angle of a ramp as well as a protractor? Change: ramp angle. Measure: MPU6050 reading. Practice in the simulator.
25. How steep can a ramp be before a toy car slips? Change: angle. Measure: tilt at the moment it slides. Needs hardware.
Rules worth knowing before you start
Fairs affiliated with Regeneron ISEF follow the Society for Science’s international rules. Under those rules, any project that measures people, including one where you are the only person tested, is human participant research and needs approval from an Institutional Review Board before any recruiting or data collection starts. That covers ideas 1 to 6, even if the only subject is you. Ask your teacher about your fair’s Scientific Review Committee early, because approval takes time.
Anything that heats, cuts or involves mains power needs an adult. None of these ideas require anything beyond a USB-powered board and low-voltage parts.
Questions
Can I use simulator data in my science fair project?
For some questions, yes: reaction time data comes from a real person, and circuit measurements test the theory the simulator is built on. For anything about the physical world, such as temperature, light or distance, collect the real data on hardware and use the simulator to build and debug first. Say which you did in your write-up.
Do I need to know how to code?
Not for the five ready-to-run circuits: each one already has its sketch. Changing what gets measured means editing the sketch, which compiles in the browser.
Build this for real
Open the editor, change a value and watch the number move with it. Nothing to install, and no account needed.