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Phone magnetometer interactions

Author's working classification for designing games and interactions. Options can overlap and combine; the list is not a generally accepted standard or proven exhaustive list. Application examples are conditional unless a specific verifiable observation is indicated nearby. Sources support individual techniques and technical limitations.

Families: 12Variants: 96Updated: 2026-10-20
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Mechanics catalog

1Phone headingOverview and example ↗The azimuth of the phone relative to the magnetic landmark is converted into the direction of the sight, the choice of sector or route.8

Variants and applications

  • Aiming by direction. Action: Rotate the phone; azimuth sets the horizontal angle of the sight. Application: Artillery, search for constellations, audio shooting range around the player. Limitations: A tilt is required for the vertical sight; The accuracy of the compass depends on the environment. Equipment: Phone without external magnet. Preparation: Easy start. Type: Input method.
  • Radial menu. Action: Point the phone at one of the corner sectors; sector selects a command. Application: Select a spell, answer, tool without touching the screen. Limitations: Need wide sectors and switching delay at the boundaries. Equipment: Phone without an external magnet. Preparation: Easy start. Type: Input method.
  • The world according to the cardinal points. Action: In each direction, open a different layer or area of ​​the world. Application: Four kingdoms, orientation, spatial audio history. Limitations: Content related to azimuth, not real location. Equipment: Phone without external magnet. Preparation: Easy start. Type: Game rule.
  • Combining directions. Action: Align azimuth with a given angle within tolerance. Application: Antenna alignment, door lock, beam reflection. Limitations: Add tolerance and explicit confirmation of hit. Equipment: Phone without external magnet. Preparation: Easy start. Type: Game rule.
  • Forbidden sector. Action: Consider the phone entering a dangerous sector as an error. Application: Do not look at the monster, do not direct the beam at the guard. Limitations: Use tolerance and reaction time so that the noise does not punish the player. Equipment: Phone without an external magnet. Preparation: Easy start. Type: Game rule.
  • 360 degree view. Action: Rotating the phone reveals parts of the panorama and ambient sound. Application: Panoramic quest, searching for objects, musical layers around the player. Limitations: The compass sets the world azimuth; smoothness is usually ensured by a gyroscope. Equipment: Phone without an external magnet. Preparation: Needs setup. Type: Input method.
  • Relative zero. Action: Save current direction; subsequent angles are considered relative to it. Application: Controlling the turret from a comfortable position, menu relative to the chair. Limitations: If north is not needed, a gyroscope is often preferable to a magnetometer. Equipment: Telephone without an external magnet. Preparation: Easy start. Type: Input method.
  • Return to direction. Action: Show the direction, hide the hint and ask to restore it. Application: Spatial memory training, landmark puzzle. Limitations: Estimate angular error with a tolerance, rather than requiring an exact match. Equipment: Phone without external magnet. Preparation: Easy start. Type: Game rule.
2Rotation over timeOverview and example ↗A change in direction over time sets the turn, sequence, or rhythm of an action; For sustainability, the environment is taken into account.8

Variants and applications

  • Sequence of directions. Action: Turn to several azimuths in a given order. Application: Combination lock, ritual route, command repetition. Limitations: Separate the achieved sector from a random intersection along the way. Equipment: Telephone without an external magnet. Preparation: Easy start. Type: Game rule.
  • Code with direction of rotation. Action: Distinguish between approaching a corner clockwise and counterclockwise. Application: Safe, rotating mechanism, navigation riddle. Limitations: You need to turn the corner through the transition 359→0 degrees. Equipment: Phone without an external magnet. Preparation: Needs setup. Type: Game rule.
  • A few turns. Action: Count complete turns and their direction. Application: Start a mechanism, wind a rope, load an artifact. Limitations: Count angle increments; turning too fast requires a gyroscope. Equipment: Phone without external magnet. Preparation: Needs setup. Type: Game rule.
  • Staying on course. Action: Maintain the direction inside the window for several seconds. Application: Antenna stabilization, concentration, channel protection. Limitations: Use the tolerance window and pause when the compass is unreliable. Equipment: Phone without an external magnet. Preparation: Easy start. Type: Game rule.
  • Rhythm of turns. Action: Reach corner sectors on the beat. Application: Dance game, musical battle, light conductor. Limitations: The event of entering a sector is better assessed with a time window. Equipment: Phone without an external magnet. Preparation: Needs setup. Type: Game rule.
  • Swinging between boundaries. Action: Alternately achieve two given directions. Application: File, pendulum, rocking a boat, bellows. Limitations: Determine a complete cycle between boundaries, and not count noise. Equipment: Telephone without an external magnet. Preparation: Easy start. Type: Game rule.
  • Turning speed. Action: Link the rate of change of world azimuth with the power of the action. Application: Acceleration of a vortex, panorama control, dosing of rotation. Limitations: The compass derivative is noisy; combination with a gyroscope is practically useful. Equipment: Phone without an external magnet. Preparation: Needs setup. Type: Input method.
  • Tracking moving azimuth. Action: Keep the phone on the target's direction, changing over time. Application: Satellite tracking, radar alignment, duel of attention. Limitations: Target speed and tolerance must take into account the delay of the sensors. Equipment: Phone without an external magnet. Preparation: Easy start. Type: Game rule.
3Using a magnet as a buttonOverview and example ↗Approaching and moving away the magnetic source crosses the signal threshold and creates a discrete command.8

Variants and applications

  • Bring it to activate. Action: Apply the magnet; exceeding the field change threshold triggers the action. Application: Physical key, scanner launch, contactless button. Limitations: Select the threshold after background measurement; strong field may saturate the sensor. Equipment: Phone and external magnet. Preparation: Easy start. Type: Input method.
  • Remove to activate. Action: Remove the magnet from its fixed place; changing the field triggers the action. Application: Pull out the pin, remove the seal, remove the battery in the quest. Limitations: Check state transition; a permanent magnet can affect auto-calibration. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • Magnet retention. Action: Maintain a magnet in the active zone as long as an action is needed. Application: Shield, beam, healing channel, door holding. Limitations: Different entry and exit thresholds are needed, otherwise the state rattles. Equipment: Phone and external magnet. Preparation: Easy start. Type: Input method.
  • Double magnetic pulse. Action: Apply and remove the magnet twice in a limited time. Application: Double shot, tool change, confirmation of a rare action. Limitations: Set the minimum interval and protection against re-activation. Equipment: Phone and external magnet. Preparation: Easy start. Type: Input method.
  • Short and long impulse. Action: Distinguish the duration of stay in the active zone. Application: Light and heavy attack, short and long command. Limitations: The user needs clear feedback about the recognized duration. Equipment: Phone and external magnet. Preparation: Easy start. Type: Input method.
  • Confirmation by letting go. Action: Input begins when presented, confirmed when magnet is removed. Application: Load and release shot, select and apply action. Limitations: Do not confuse loss of signal due to phone movement with intentional release. Equipment: Phone and external magnet. Preparation: Easy start. Type: Game rule.
  • Several rapids. Action: Go through successive levels of field change. Application: Charge stages, gear shifting, three lever positions without mechanics. Limitations: Levels require calibration; the field is not equal to the distance in centimeters. Equipment: Telephone and external magnet. Preparation: Needs setup. Type: Input method.
  • The rhythm of approaches. Action: Alternate active and inactive states according to the pattern. Applications: Magnetic alphabet, rhythm game, signal repetition. Limitations: Works as a time code, not as a transfer of the unique personality of the item. Equipment: Phone and external magnet. Preparation: Easy start. Type: Game rule.
4Field strength as analog inputOverview and example ↗The relative change in magnetic field sets a continuous parameter after setting the range and neutral state.8

Variants and applications

  • Analog proximity. Action: Smoothly change the distance to the magnet; the normalized change in the field sets the parameter. Application: Gas, volume, note pitch, spell intensity. Limitations: Approximation does not always increase the module of the total field; calibrate the working trajectory. Equipment: Phone and external magnet. Preparation: Needs setup. Type: Input method.
  • Window setting. Action: Find and hold the value between the lower and upper threshold. Application: Set up the radio station, stabilize the reactor, open the lock. Limitations: The window must be wider than the noise and accessible in a comfortable position. Equipment: Telephone and external magnet. Preparation: Easy start. Type: Game rule.
  • Risk of overload. Action: Increase the value, stopping to a dangerous threshold. Application: Risky charge, overheating, resource extraction on the edge. Limitations: Overload is a game rule; do not require physical saturation of the sensor. Equipment: Phone and external magnet. Preparation: Easy start. Type: Game rule.
  • Accumulation of impact. Action: Accumulate game resource based on time and magnitude of field change. Application: Energy transfer, charging, melting, slow hacking. Limitations: The game scale is integrated; readings do not measure physical energy transferred. Equipment: Telephone and external magnet. Preparation: Easy start. Type: Game rule.
  • Repeating the curve. Action: Repeat the target signal strength graph by moving the magnet. Application: Musical phrase, precision manufacturing, training simulator. Limitations: Compare smoothed normalized curves with time tolerance. Equipment: Phone and external magnet. Preparation: Needs setup. Type: Game rule.
  • Reaction to growth and decline. Action: Separately interpret the increase and decrease of the signal. Application: Inhale and exhale the creature, tighten and loosen, pump the pump. Limitations: A derivative dead zone and speed restrictions are needed. Equipment: Phone and external magnet. Preparation: Needs setup. Type: Input method.
  • Search for extremum. Action: Move the source or telephone, comparing local maxima and minima. Application: Find the tuning point, minimize interference, conduct research. Limitations: Local extremum does not guarantee the closest point to the magnet. Equipment: Telephone and external magnet. Preparation: Needs setup. Type: Game rule.
  • Signal stability. Action: Maintain the selected value with minimal fluctuations. Application: Neutralization, concentration, adjustment of musical tone. Limitations: Phone and surroundings must be fairly still. Equipment: Phone and external magnet. Preparation: Easy start. Type: Game rule.
5Vector and polarityOverview and example ↗The field vector components and polarity changes differentiate the states of the magnet in the prepared geometry.8

Variants and applications

  • Two polarities. Action: Turn over a known magnet in one socket; two patterns give two commands. Application: Light and dark, heating and cooling, two sides of the key. Limitations: The axis sign itself does not determine the north pole at any position. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • Three states of polarity. Action: Distinguish between the absence of a magnet and its two orientations in the socket. Application: Three-position switch, plus/zero/minus, logic gate. Limitations: Store three templates for a specific magnet and seat. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • Selection by leading axis. Action: In limited positions, distinguish which component of the field change predominates. Application: Three types of influence, switching axes, physical classification. Limitations: Does not promise recognition of arbitrary sides of the phone without training. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • Vector pattern matching. Action: To achieve the coincidence of the normalized direction and magnitude of the field with the sample. Application: Magnetic lock signature, configuration restoration, laboratory riddle. Limitations: Different configurations can give similar measurements at one point. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Game rule.
  • Rotation of a magnet on an axis. Action: Rotate a magnet with a fixed center and axis; templates set the angle. Application: Adjustment knob, turn the key, control wheel. Limitations: A mechanism and a choice of axis that gives a discernible change in the field are needed. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • The cursor is on a given plane. Action: Move one magnet along a calibrated surface with a fixed orientation. Application: Cursor, labyrinth, control of a chip next to the screen. Limitations: Accuracy and unambiguity depend on geometry; This is not free 3D tracking. Equipment: Magnetic props with a given geometry. Preparation: Experimental. Type: Input method.
  • Spatial magnetic zones. Action: Train several positions of the magnet near the phone and recognize the selected zone. Application: Off-screen menu, inventory pockets, element selection by gesture. Limitations: Start with a small number of clearly distinguishable zones and the “not sure” state. Equipment: Magnetic props with a given geometry. Preparation: Experimental. Type: Input method.
  • Balance of two sources. Action: Move the magnet on the guide relative to the stationary source, achieving the target total field. Application: Balance of forces, adjusting the compensator, physical puzzle. Limitations: The sensor sees the sum of the deposits; separate positions of two magnets are not restored. Equipment: Magnetic props with a given geometry. Preparation: Experimental. Type: Game rule.
6Gestures with a magnetOverview and example ↗The time sequence of magnet movements is recognized as a gesture with tolerances for distance and speed.8

Variants and applications

  • Magnetic swing. Action: Swipe a magnet through a calibrated area from left to right or back. Application: Swinging a weapon, flipping, deflecting a projectile. Limitations: Direction requires learning patterns, not a single field module threshold. Equipment: Phone and external magnet. Preparation: Needs setup. Type: Input method.
  • Push and pull. Action: Distinguish between the sequences of zoom-remove and remove-zoom. Application: Push or pull an object, throw out or draw in energy. Limitations: Limit the trajectory; the starting position affects the signal pattern. Equipment: Telephone and external magnet. Preparation: Needs setup. Type: Input method.
  • Circle gesture. Action: Move the magnet in a circle in a selected plane. Application: Create a portal, mix a potion, charge a circular attack. Limitations: Requires discernible patterns; turning the magnet itself may distort the signal. Equipment: Phone and external magnet. Preparation: Experimental. Type: Input method.
  • Eight gesture. Action: Repeat two connected paths in the work area. Application: Complex spell, special move, ritual design. Limitations: This is limited gesture recognition; do not pass off as measuring an exact contour. Equipment: Telephone and external magnet. Preparation: Experimental. Type: Input method.
  • Zigzag or broken line. Action: Alternate directions of movement according to a trained pattern. Application: Lightning, cutting, connecting virtual contacts. Limitations: Too similar gestures require a simplified vocabulary. Equipment: Phone and external magnet. Preparation: Experimental. Type: Input method.
  • Wrist rotation with magnet. Action: Distinguish characteristic changes in the orientation of a magnet on a ring or holder. Application: Rotate an object, switch tool mode, rotate a virtual pen. Limitations: Hand movement and change in magnet position are mixed in one signal. Equipment: Phone and external magnet. Preparation: Experimental. Type: Input method.
  • Dictionary of user gestures. Action: Record several repetitions of gestures and match the new signal with patterns. Application: Personal spells, accessible input, secret game command. Limitations: Requires training, checking for false positives and refusing to answer confidently when in doubt. Equipment: Phone and external magnet. Preparation: Experimental. Type: Input method.
  • Gesture speed profile. Action: Distinguish similar movements by the “slow-fast-slow” pattern. Application: Quality of impact, musical articulation, manufacturing technique. Limitations: Estimation of speed is relative without a known trajectory; Temporary patterns are compared. Equipment: Phone and external magnet. Preparation: Experimental. Type: Game rule.
7Passive physical controllersOverview and example ↗Magnetic props turn the physical movement of a knob, slider, or other mechanism into a phone signal.8

Variants and applications

  • Mechanical button. Action: Press a button that moves a magnet or part in a known field. Application: Passive gamepad, trigger, button on the back of the phone. Limitations: Select the position relative to the real sensor and provide for return. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • Linear slider. Action: Move the magnet along a guide with given ends. Application: Gas, volume, damper position, inventory on a physical scale. Limitations: Requires calibration of the nonlinear dependence of the signal on position. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • Rotary handle. Action: Rotate the magnet in the housing along a fixed circle or axis. Application: Steering wheel, radio tuning, music controller, safe. Limitations: Not every axis of rotation gives an unambiguous signal; test the full range. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • Joystick with centering. Action: Deflect the magnetic arm in a limited area; the spring returns it. Applications: Character movement, camera control, analog selection. Limitations: Neutral and deflection areas need training; This is not a replacement for a full-fledged Hall joystick without development. Equipment: Magnetic props with a given geometry. Preparation: Experimental. Type: Input method.
  • Compression through an elastic part. Action: Compress a spring or elastic element that displaces a magnet. Applications: Grip force, shooting force, musical dynamics. Limitations: Displacement is measured; force can only be assessed through calibrated mechanics. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • Accessory bend. Action: Bend a plate or arc with a magnet, changing its position. Application: Tensioning a bow, deforming a material, controlling a flexible tool. Limitations: Fix the attachment point and check repeatability after repeated bending. Equipment: Magnetic props with a given geometry. Preparation: Experimental. Type: Input method.
  • Crank or handle. Action: Rotate a fixed magnet using a cyclic mechanism. Application: Fishing rod reel, meat grinder, wind-up toy, resource generator. Limitations: The rotation speed is limited by the sampling frequency; skipping cycles must be detected. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • Lever with fixation. Action: Move the mechanism between stable positions. Application: Gearbox, switch, physical mode switch. Limitations: It is necessary to check whether auto-calibration compensates for a long-term constant state. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
8Objects and physical tokensOverview and example ↗Prepared objects receive distinguishable magnetic characteristics; recognition depends on location and calibration.8

Variants and applications

  • Inserting a physical key. Action: Insert a magnetic object into the only prepared slot. Application: Open the door, start the plot, activate the artifact. Limitations: A familiar field configuration is detected; copy protection is not provided. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Game rule.
  • Selecting an item by signature. Action: Insert prepared objects with different magnetic templates into one slot one by one. Application: Character figures, physical inventory, tool selection. Limitations: Classes may overlap; you need a small proven set and exact position. Equipment: Magnetic props with a given geometry. Preparation: Experimental. Type: Input method.
  • Side or orientation of the token. Action: Flip or rotate one token in a fixed location. Application: Selecting the face of the card, the state of the hero, the direction of action. Limitations: Distinction of orientations must be checked on a specific design. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • A chip on a marked path. Action: Move one magnetic chip along known points or cells. Application: Tabletop labyrinth, route, local tactical task. Limitations: One sensor does not provide a reliable complete picture of several chips on a large field. Equipment: Magnetic props with a given geometry. Preparation: Experimental. Type: Input method.
  • Sequence of presentations. Action: Apply prepared items one at a time in a given order. Application: Potion recipe, story from cards, assembling a team. Limitations: The application stores the order; it does not detect all objects lying nearby at once. Equipment: Magnetic props with a given geometry. Preparation: Experimental. Type: Game rule.
  • Magnetic code scanning. Action: Guide media with large magnetic marks through the guide. Application: Physics program, toy command, code page. Limitations: Special slow code; reading banking magnetic stripes is not expected. Equipment: Magnetic details with a given geometry. Preparation: Experimental. Type: Input method.
  • Opening a page or flap. Action: Move a magnet along with a known fold or a separate page. Application: Interactive book, box, drop-down object. Limitations: Many magnets give a total field; start with one moving part. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Input method.
  • Assembly step control. Action: Bring the next module to a single reading zone before installation. Application: Educational constructor, sequential assembly of the device, repair in a quest. Limitations: The presentation of the module is confirmed, and not the correctness of the entire structure. Equipment: Magnetic props with a given geometry. Preparation: Experimental. Type: Game rule.
9Search and interaction with spaceOverview and example ↗Changes in the magnetic environment become a condition for searching or orienting in the surveyed area.8

Variants and applications

  • Magnetic “hot-cold”. Action: Move the phone and use the relative signal to look for a hidden magnet. Application: Treasure search, detective, examination of an object with a scanner. Limitations: The signal is local and does not have to grow monotonically towards the target; record orientation when comparing. Equipment: Surveyed or prepared site. Preparation: Needs setup. Type: Game rule.
  • Field map. Action: Take readings at marked points and build a map. Application: Research game, training, search for anomalies, installation map. Limitations: Coordinates are set by a person, camera or other tracker; the magnetometer itself does not measure them. Equipment: Surveyed or prepared site. Preparation: Needs setup. Type: Application script.
  • Route recognition by fingerprint. Action: Match field sequence to pre-recorded passages. Application: Museum route, building quest, additional landmark without GNSS. Limitations: Requires map, matching and usually inertial data; portability between phones is checked. Equipment: Surveyed or prepared site. Preparation: Experimental. Type: Application script.
  • Scene by zone. Action: Recognize a prepared area by local magnetic pattern. Applications: Sound history, exposure, changing game environments. Limitations: Do not rely on a single field value as a unique room address. Equipment: Surveyed or prepared area. Preparation: Experimental. Type: Game rule.
  • Magnetic control points. Action: Take turns to detect prepared local marks. Application: Toy track, quest route, control of stages. Limitations: Requires verified points and a limited reading distance; these are not beacons for tens of meters. Equipment: Surveyed or prepared site. Preparation: Needs setup. Type: Game rule.
  • Gradient comparison. Action: Measure the field at several close positions and select the next direction based on the difference. Application: Source investigation, virtual instrument, local anomaly search. Limitations: This is a spatial comparison of successive measurements, not a gradient from a single sample. Equipment: Surveyed or prepared site. Preparation: Experimental. Type: Game rule.
  • Avoiding magnetic interference. Action: Stay below the threshold for deviation from the local background. Application: Stealth near prepared sources, contaminated areas, device protection. Limitations: You need to examine the playground; random metal objects can change the difficulty. Equipment: Surveyed or prepared area. Preparation: Needs setup. Type: Game rule.
  • Magnetic seal failure. Action: A fixed telephone monitors the status of a magnet on a lid or object. Applications: Story alarm, trap, drawer opening detection. Limitations: This is a game prop; background OS restrictions and false positives interfere with security promises. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Application script.
10Combinations with other channelsOverview and example ↗The magnetic signal complements touch, movement, sound or image, maintaining a separate role for each channel.8

Variants and applications

  • Touch plus direction. Action: Point the phone at the world azimuth and confirm with a touch. Application: Shot, target selection, directed dialogue, command to a squad. Limitations: The magnetometer sets a horizontal reference; touch separates intention from inspection. Equipment: Telephone without external magnet. Preparation: Easy start. Type: Compound mechanics.
  • Magnetic touch modifier. Action: Hold the magnet in the area; touches at this moment have a different meaning. Application: Alternate fire, second layer of the tool, temporary editing mode. Limitations: Check the independence of the magnetic signal from movements when touching. Equipment: Phone and external magnet. Preparation: Needs setup. Type: Compound mechanics.
  • Slope plus magnetic parameter. Action: By tilting the phone, set one parameter, by moving the magnet another. Application: Steering wheel and gas, aim and strength, melody and volume. Limitations: Need to compensate for changes in the orientation of the phone; the original vector background is rotated. Equipment: Phone and external magnet. Preparation: Experimental. Type: Compound mechanics.
  • Action only when stationary. Action: Allow magnetic gesture only when the gyroscope and accelerometer indicate a stable position. Application: Accurate input, key confirmation, reduction of accidental activations. Limitations: This is a software condition; Motion sensors by themselves do not remove all magnetic interference. Equipment: Phone and external magnet. Preparation: Needs setup. Type: Compound mechanics.
  • Geoposition plus azimuth. Action: At a known geographical point, look in the required direction. Application: City quest, search for landmarks, orientation. Limitations: Geoposition is supplied separately; for geographic north, a declination correction is needed. Equipment: Phone without an external magnet. Preparation: Needs setup. Type: Compound mechanics.
  • Camera plus magnetic channel. Action: The camera determines an object or pose, the magnet sets an additional mode or confirmation. Application: AR artifact, physical toy with a digital effect, interactive stand. Limitations: Positioning is provided by the camera; The magnetometer does not replace visual tracking. Equipment: Phone and external magnet. Preparation: Experimental. Type: Compound mechanics.
  • Input with sound and vibration feedback. Action: Find the desired sector or signal strength by sound or vibration without constantly looking at the screen. Application: Audio game, educational device, accessible interface. Limitations: Accessibility requires verification with users; This is a form of feedback, not a new sensor. Equipment: Phone and external magnet. Preparation: Needs setup. Type: Compound mechanics.
  • Voice plus magnetic gesture. Action: Say a command, and use a magnet to select the intensity or confirm execution. Application: Voice spell, musical instrument, props control. Limitations: Voice is recognized by a microphone; provide a mode in noise and without speech. Equipment: Telephone and external magnet. Preparation: Experimental. Type: Compound mechanics.
11Cooperative play and rolesOverview and example ↗Participants distribute monitoring, control and signal exchange among several prepared devices.8

Variants and applications

  • Split controller. Action: One player holds the phone, the other controls the magnet. Application: Cooperative piloting, reactor setup, communication game. Limitations: Separate roles and limit the work area; two independent movements complicate the signal. Equipment: Several players and prepared devices. Preparation: Needs setup. Type: Compound mechanics.
  • Coincidence of team directions. Action: Several phones simultaneously reach specified azimuths. Application: Team ritual, synchronous defense, distributed puzzle. Limitations: Requires data exchange and synchronization; Local magnetic interference varies. Equipment: Multiple players and prepared devices. Preparation: Needs setup. Type: Compound mechanics.
  • Complementary directions. Action: Each player must maintain his own direction, complementary to the others. Application: Close the circle of protection, cover sectors, distribute surveillance. Limitations: The condition is checked by the application; the direction of each phone to another does not follow from this. Equipment: Several players and prepared devices. Preparation: Needs setup. Type: Compound mechanics.
  • General turn token. Action: Pass one magnetic object and present it to the phone of the next player. Application: Move in a board game, physical voting rights, relay race. Restrictions: The right to move is supported by the rules and the application; the magnetic token can be copied. Equipment: Several players and prepared devices. Preparation: Needs setup. Type: Compound mechanics.
  • Drag the summary field. Action: Two players move magnets on guides, trying to bring the common signal into their area. Application: Tug of war, balance, struggle for adjustment. Limitations: Only the total field is evaluated; The individual contribution of each player is not measured. Equipment: Multiple players and prepared devices. Preparation: Experimental. Type: Compound mechanics.
  • Discovery relay. Action: Bring one item to several phones in the right order. Application: Physical relay race, artifact delivery, joint route. Limitations: The magnet itself does not transfer the digital state; the order is verified over the network or on one device. Equipment: Multiple players and prepared devices. Preparation: Needs setup. Type: Compound mechanics.
  • Hidden input of the second player. Action: The player with the magnet makes a permitted gesture outside the screen owner's field of view. Application: Asymmetrical riddle, trick, search for saboteur. Limitations: The phone must recognize a limited vocabulary of actions; there is no reading of thoughts or personality here. Equipment: Several players and prepared devices. Preparation: Experimental. Type: Compound mechanics.
  • Controlled magnetic intervention. Action: One player tries to hold the target on a signal, the other changes the field with the prepared props. Application: Asymmetrical combat, sabotage of the device, game to regain control. Limitations: Intervention is the rule; next to a magnet, a compass cannot be considered a reliable world reference. Equipment: Several players and prepared devices. Preparation: Experimental. Type: Compound mechanics.
12Applied, educational and creative scenariosOverview and example ↗Observing and changing the magnetic signal is used for research, creativity and learning without the promise of laboratory instrument precision.8

Variants and applications

  • Field visualization. Action: Show components and field module in real time. Application: Educational Teslameter, graphs, research of household sources. Limitations: These are phone sensor readings; Accuracy depends on model and calibration. Equipment: Phone without external magnet. Preparation: Easy start. Type: Application script.
  • Comparison of magnetic objects. Action: In the same position, compare the relative readings from the samples. Application: Physics lesson, sorting prepared samples, studying magnets. Limitations: Not a universal metal detector: copper, aluminum and any hidden objects are not detected reliably. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Application script.
  • Study of poles and field lines. Action: Invert a known magnet and measure the field at marked points. Application: School experiment, interactive explanation of vector and superposition. Limitations: Interpret polarity only taking into account the geometry and coordinate system. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Application script.
  • Coil as a signal source. Action: External controlled coil creates slow field changes for recognition. Application: Current training experience, prepared beacon, low speed command. Limitations: Requires external electronics, tested field levels and frequencies; This is not NFC or a radio modem. Equipment: External active electronics. Preparation: Experimental. Type: Application script.
  • Counting machine cycles. Action: A magnet attached to a slowly rotating mechanism produces a periodic signal. Applications: Toy tachometer, revolution counter, frequency study. Limitations: Sampling rate and filters limit speed; Missing pulses and aliasing need to be checked. Equipment: Magnetic props with a given geometry. Preparation: Experimental. Type: Application script.
  • Scoring and field drawing. Action: Convert a signal into sound, color, shape or movement. Applications: Music installation, generative art, sensory learning. Limitations: This is an artistic display; sound strength or brightness is not the physical energy of the field. Equipment: Telephone and external magnet. Preparation: Easy start. Type: Application script.
  • Alternative physical input. Action: Set up a convenient magnetic switch or regulator in a stable mount. Application: Input with difficult touch, large button, operation with gloves. Limitations: Design and force are selected with the user; a backup control method is needed. Equipment: Magnetic props with a given geometry. Preparation: Needs setup. Type: Application script.
  • Accessory profile. Action: Recognize the prepared accessory when attached and change the application mode. Application: Working panel, camera mode, game profile, interactive stand. Limitations: Support depends on geometry and OS; the launch of system actions is not guaranteed, MagSafe is not equal to the identification API. Equipment: Magnetic props with a given geometry. Preparation: Experimental. Type: Application script.

Equipment

phone

Description: Phone without external magnet

magnet

Description: Phone and external magnet

fixture

Description: Magnetic props with a given geometry

place

Description: Surveyed or prepared site

multi

Description: Multiple players and prepared devices

active

Description: External active electronics

Preparation

basic

Description: Easy start

tune

Description: Needs setup

experiment

Description: Experimental

Types

input

Description: Input method

Rule

Description: Game rule

composite

Description: Compound Mechanics

scenario

Description: Application script

What are mechanics made of?

B = (Bx, By, Bz)

Field at one point

The sensor measures three components of the magnetic field in microteslas. From these, module, change relative to background, and temporal patterns are obtained. Android: Position sensors Apple: CMMagnetometerData

Azimuth + time

Phone heading

The compass uses the field along with a vertical estimate. The gyroscope helps with fast movement. Geographic north requires correction; it is different from magnetic. Apple: trueHeading

ΔB + geometry

External props

A magnet, guide, button or prepared area turns the field change into a controlled signal. Without a given geometry, the position and orientation of the source are ambiguous.

How to choose a development direction

Conditions Suitable mechanics First prototype

Phone only Azimuth, wide sectors, heading hold Combine direction and confirm by touch: M004 + M073

There is a separate magnet Button, hold, rhythm, analog scale. Place the magnet and hold the value in the window: M017 + M026

Can be made accessory Button, slider, knob, lever, tokens One slider with known ends: M050

There is a platform or several players Search, control points, divided roles Find a prepared source for feedback: M065

Where is the limit of possibility?

No free 3D tracking

Three field values ​​are usually insufficient to unambiguously reconstruct the unknown position and orientation of the magnet. A guide, a known orientation, a map, additional sensors, or another tracking system can help.

There is no universal distance

The signal depends on the strength and orientation of the magnet, the direction of movement, the background field and the phone model. Approaching a magnet does not have to monotonically increase the modulus of the total field.

No independent channels for many magnets

The phone measures the total field at the sensor location. Several objects must be read sequentially, their states must be limited, or a small set of pre-tested combinations must be recognized.

Compass and local magnet conflict

If a magnet deliberately changes the field, the compass may no longer show world azimuth. Simultaneous local input and orientation require a separate compensation model, gyroscope, or other reference source.

Calibration depends on the application

Separate natural field measurement from artificial magnetic gestures. Auto-calibration is capable of changing the stable signal from the accessory. On Android, check calibrated and uncalibrated data; these are different APIs. Android: Position sensors

Tilt and shake are not specific to the magnetometer

An accelerometer and a gyroscope are designed for them. On Android, TYPE_GAME_ROTATION_VECTOR specifically does not use a magnetic field. If communication with the north or an external magnet is not needed, a magnetometer may be superfluous. Android: Position sensors

You can't promise a universal metal detector

Response to magnetic sources and some ferromagnetic objects is available under suitable conditions. Reliable detection of any metals, wiring, people and hidden objects does not follow from this.

The sensor measures, not attracts

The magnetometer does not create a controlled magnetic field and does not move objects. The magnets in the phone case also do not become a software-controlled drive. Magnetometer, Hall lid sensor, NFC and MagSafe are different mechanisms.

There are hardware and platform limitations

Check sensor availability, range, actual frequency and API availability. A strong magnet can push readings out of range. The frequency of recording in the application may differ from the requested one; fast cycles require separate testing.

Web is not equal to native app

As of October 20, 2026, the W3C documentation indicates that the raw Magnetometer API is not available by default in browser engines. HTTPS and permissions alone do not guarantee support. Orientation events are not the same as accesses to Bx, By, Bz. W3C: Magnetometer, May 14, 2026

Verification on devices is required

Find the sensor position; measure the background with and without a cover; test orientations, interference and operating distances. For prototypes, choose a weak, sufficient source and a mount that does not require a strong magnet near the camera. MagPie, CHI 2025

How to use the catalog

Separate player action, signal recognition, game rule, and feedback. The related variants here preserve the context of application and are not necessarily independent physical primitives.

When prototyping, test one rule and failure conditions first. The presence of an API, sensor, or source does not prove that all scenarios work. For devices, test feature availability, calibration, and alternate input on the actual target hardware.

Sources and examples

Sources support particular techniques or methodology, not every family variant. Design examples and mechanic combinations are illustrative.

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