Tags

WoowTech can turn a physical token into an automation trigger. Whatever tag technology you happen to own will work — the platform doesn't care about the underlying format. Out of the box, the official mobile apps recognize NFC stickers and cards, and there's also a build-it-yourself standalone reader for households that want a fixed scanning station.

Programming your first tag

The quickest path is a pack of cheap NFC stickers or cards combined with the official WoowTech mobile app. Once you've written data onto a card from the app, just bring your phone up to it again to read it back.

Background NFC scanning (reading a tag without first opening an app) is limited to iPhone XS, XR, iPhone 11, and newer handsets.

The tag dashboard

WoowTech includes a purpose-built screen for handling tags. From there you can give a tag a readable name, attach automations to it, or remove tags you no longer use. Open that same dashboard from inside the mobile app and you gain the extra ability to write tags directly.

Entities

Registering a tag produces a matching tag entity. These entities are convenient in automations and on dashboards because they remember the instant the tag was last read. The entity's state stores that read moment as a datetime, for instance 2013-09-17T07:32:51.095+00:00.

Attributes

Project idea: an RFID-style jukebox

A popular trick is starting music the moment a tag is read. The automation keeps two small dictionaries: one that ties each reader device to a media player, and another that ties each tag to the music it should play. When the tag fires its event, the automation looks up both values and tells the right player to start the right track.

To discover a reader's device ID, open Developer tools > Events, subscribe to tag_scanned, scan a tag on that reader, and copy the device_id from the payload.

automation:
  - alias: "Jukebox: play album when tag scanned"
    triggers:
      - trigger: event
        event_type: tag_scanned
    action:
      - variables:
          # reader device -> speaker mapping
          speakers:
            "livingroom_reader_devid": media_player.living_room_speaker
            "bedroom_reader_devid": media_player.bedroom_sonos
          # tag -> content mapping
          tracks:
            "f00dface": "spotify:album:1DFixLWuPkv3KT3TnV35m3"
            "deadbeef": "spotify:playlist:37i9dQZF1DXcBWIGoYBM5M"
          target_speaker: "{{ speakers[trigger.event.data.device_id] }}"
          target_track: "{{ tracks[trigger.event.data.tag_id] }}"
      - action: media_player.play_media
        target:
          entity_id: "{{ target_speaker }}"
        data:
          media_content_id: "{{ target_track }}"
          media_content_type: music

Making your own printed tags

Plain NFC stickers are the easy way to make an object you already own scannable. If you'd rather hand someone a card, blank printable NFC cards exist too, and they're simple enough that even young children can use them.

To print cards yourself you'll need:

• A Canon TS702a inkjet printer
• The dedicated tray that feeds cards through that printer
• Blank printable NFC cards
• A browser-based ID card designer that builds a print-ready PDF entirely in your browser (nothing is uploaded to a server)

The tag_scanned event

Each successful read emits a tag_scanned event carrying the following data: