Vernier Software and Technology
Vernier Software & Technology

Magnet Finder


A shell game is a contest in which a person hides a small object underneath one of three nutshells, cups, or thimbles, and then rapidly shuffles them about on a flat surface. The spectators must pay close attention during the shuffling process in order to try and guess the final location of the hidden object. It is typically a sleight-of-hand swindling game. In this project, your challenge is to build a robot to play the shell game with you. The robot will act as the spectator, while you will hide a magnet under one of three walnut shells. Then the robot will use a Vernier Magnetic Field Sensor to determine the location of the hidden magnet.


In this project, you will design and build a mobile robot for pinpointing the location of a hidden magnet. The magnet should be hidden under one of three identical objects, such as walnut shells. The walnut shells should be laid out in a line so that the robot can drive by the shells while measuring the magnetic field of the area using a Vernier Magnetic Field Sensor. The location of the hidden magnet will be determined by feedback from the sensor of the strongest reading. Your robot should return to the location of the hidden magnet and give an audio indicator.

Sensors and Equipment

This project/activity features the following Vernier sensors and equipment.

Additional Requirements

You will also need NXT Sensor Adapter and a LEGO MINDSTORMS NXT robotics system.

Standards Correlations

See all standards correlations for STEM 2 with Vernier and LEGO® MINDSTORMS® NXT »

STEM 2 with Vernier and LEGO® MINDSTORMS® NXT

See other experiments from the lab book.

2First-Class Levers
3Audio Assistant
6String Tension Tester
7Gas Pressure
8Yeast in Action
9Grip Strength
10Cartesian Diver
12Lemon Battery
13Battery Tester
14Solar Cells
15Solar Tracker
16Mapping a Magnetic Field
18Migrating Robot
19Magnet Finder
20Mine Sweeper

Project/activity 19 from STEM 2 with Vernier and LEGO® MINDSTORMS® NXT Lab Book

<em>STEM 2 with Vernier and LEGO<sup>®</sup> MINDSTORMS<sup>®</sup> NXT</em> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

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