{"schemaVersion":1,"record":{"key":"mechanic/phone-magnetometer--family-03","type":"mechanic","id":"phone-magnetometer--family-03","lang":"en","title":"Using a magnet as a button","summary":"Bringing a magnet near changes the field. A scenario can map a threshold crossing to a press and its removal to a release.","updatedAt":"2026-10-22","status":"active","url":"https://gamemechanics.pro/en/knowledge/mechanic/phone-magnetometer--family-03/","jsonUrl":"https://gamemechanics.pro/api/v1/knowledge/en/mechanic/phone-magnetometer--family-03.json","markdownUrl":"https://gamemechanics.pro/content/knowledge/en/mechanic/phone-magnetometer--family-03.md","aliases":["A magnet as a button"],"tags":["Phone magnetometer interactions","Mechanics catalog"],"sourceIds":["source-603978442e60360e"],"sources":[{"id":"source-603978442e60360e","title":"Physics Toolbox Magnetometer","url":"https://apps.apple.com/us/app/physics-toolbox-magnetometer/id1003749103?uo=4","verifiedAt":null}],"sections":[{"id":"principle","title":"How it works","body":"Approaching and moving away the magnetic source crosses the signal threshold and creates a discrete command."},{"id":"variants","title":"Variants","body":"### Variants and applications\n\n<a id=\"family-03-variants\"></a>\n\n- 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. <a id=\"variant-m017\"></a>\n- 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. <a id=\"variant-m018\"></a>\n- 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. <a id=\"variant-m019\"></a>\n- 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. <a id=\"variant-m020\"></a>\n- 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. <a id=\"variant-m021\"></a>\n- 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. <a id=\"variant-m022\"></a>\n- 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. <a id=\"variant-m023\"></a>\n- 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. <a id=\"variant-m024\"></a>"},{"id":"context","title":"Context and limits","body":"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."}],"relations":[],"placements":[{"catalogId":"phone-magnetometer","id":"family-03","title":"Phone magnetometer interactions","url":"https://gamemechanics.pro/en/mechanics/phone-magnetometer/#family-03","categoryIds":["section-1"]}],"supersededBy":[],"attributes":{"preview":{"updatedAt":"2026-10-22","title":"A magnet as a button","description":"Bringing a magnet near changes the field. A scenario can map a threshold crossing to a press and its removal to a release.","image":{"src":"images/mechanics/sensor-physics-magnet-3.webp","width":665,"height":1440,"crop":{"x":51,"y":323,"width":563,"height":1034},"game":"Physics Toolbox Magnetometer","sourceUrl":"https://apps.apple.com/us/app/physics-toolbox-magnetometer/id1003749103?uo=4","originalUrl":"https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/76/23/58/7623583b-a84f-fd15-b138-fa78cf800baa/04-record-lab-data.png/720x1560bb.jpg","credit":"Chrystian Vieyra","rights":"© Chrystian Vieyra. Developer-distributed App Store screenshot. All rights reserved; excluded from MIT and CC BY 4.0.","caption":"Physics Toolbox: a recording of sharp magnetic-field changes","alt":"Physics Toolbox: a recording of sharp magnetic-field changes","markers":[{"x":44,"y":64,"label":"A field peak can supply a threshold-action input"}]},"tips":["Use different activation and release thresholds to reduce chatter."],"examples":[{"title":"Physics Toolbox Magnetometer","url":"https://apps.apple.com/us/app/physics-toolbox-magnetometer/id1003749103?uo=4"}]}},"endsAt":null,"provenance":"Original editorial design catalog consolidated from project discussions on 2026-10-20. Complete discussion item lists and contextual limitations are preserved; linked primary sources support specific techniques, not the entire classification. English translation was prepared with machine assistance and editorial review.","license":"CC-BY-4.0","codeLicense":"MIT","attribution":"gamemechanics.pro contributors","catalogKey":"catalog/phone-magnetometer"}}