Reaction Time Challenge Kit

Classes 7-8, typical ages 12–14. Age ranges vary by learner. Guided low-voltage electronics.

Activity engagement

60–90 minutes. Explore 10–15 min · Build 20–30 min · Test and discuss 30–45 min. Estimated time for building, testing and discussion.

What you need

A computer with a USB port and Arduino IDE is required and is not included.

Included components

• Small Breadboard / Mini Solderless Board - 400 points — 1 breadboard
• Jumper Wire Combo - Male to Male, Male to Female and Female to Female Breadboard Connecting Wires (10 Qty Each) — 1 set
• Illustrated Activity Guide and Observation Sheets — 1 set
• Fitted Headers and Labelled Connection Leads — 1 set
• Arduino Uno R3 CH340G version compatible Arduino Development Board — 1 controller board
• USB A to B Programming Cable for Arduino Uno/ Arduino Mega — 1 data cable
• 5mm LED - Red Color — 1 LED
• 330 Ω 1/4 Watts (10 PCS) — 1 resistor
• Tactile Push Button Switch 12x12x8mm 4-Pin — 1 button

What you learn

• INPUT_PULLUP reads LOW when a button connects to ground.
• Elapsed time is the difference between two timestamps.
• Repeated trials reveal variation and false starts.

Connection guide

• D9 → 330 Ohm → LED anode; LED cathode → GND.
• Push button between D2 and GND; use opposite button contact pairs.

Steps to make it

1. Disconnect all power and identify the supplied part labels and pinouts before wiring.
2. Wire the LED and button; upload the reaction sketch.
3. Open Serial Monitor and keep the button released while waiting.
4. Press as soon as the LED comes on; read the elapsed milliseconds.
5. Collect ten trials and compare median, minimum and false starts.
6. Change only the named parameter for the extension, repeat the controlled trials, save observations and disconnect power afterward.

Programming resources

Arduino IDE: select Arduino Uno and the USB port. Use the supplied USB data cable. Serial Monitor/Plotter: 115200 baud.

Uses the selected board core libraries.

Download starter sketch

Test challenge

Compare normal trials with one deliberately early press.

Observation task

Trial number, reaction milliseconds, false start and median of valid trials.

Expected result

A valid response prints elapsed milliseconds; an early press is marked as a false start.

If it does not work

A permanently LOW button usually means the two jumper wires use the same internal contact pair.

Try next

Compare two sets of ten trials without claiming a medical or attention assessment.

Use and supervision

Use only the supplied low-voltage DC parts. Disconnect power before rewiring; check polarity and labelled pinouts. No soldering or exposed mains connections. Adult guidance is recommended.

How this experiment works

Download class activity guide

Cover illustrations show component types. Functional animations explain principles and are not recorded prototype tests. Follow the supplied connection labels and pinouts.