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NFC scan rally at LinuxTag 2026

Goal

At LinuxTag Villach 2026, we plan to run an interactive NFC rally that playfully guides visitors through several stands while presenting the technical and creative sides of the Node-K hackerspace.

Each visitor receives an NFC key fob in a 3D-printed case that cannot be opened. It serves both as a participation token for the rally and as a lasting giveaway pointing back to the hackerspace.

Setup

NFC key fobs

  • Every visitor receives an NFC fob with a key ring.
  • The NFC tag is hidden inside the 3D-printed case and cannot be removed.

  • Design:

    • Front: LinuxTag Villach 2026
    • Back: QR code linking to node-k.at

Visitors can take the fob home after the event as a souvenir and as an advertisement for the hackerspace.

Scan stations

  • Each participating stand receives its own scan station based on an ESP with an NFC reader.
  • When a fob is scanned, the ESP sends an event over Wi-Fi to a central terminal.
  • Wi-Fi is provided through our own hotspot.

Open scanner concept

  • Each scan station can be designed individually by a different hackerspace member.

  • Only these points are specified:

    • The technical API endpoints
    • A maximum size
    • The basic NFC scanning functionality

  • User feedback can be designed freely, for example using:

    • LEDs
    • Displays
    • Sound
    • Mechanical elements
    • Creative cases

This makes both the rally and the hackerspace's variety and creativity visible.

Software and system concept

Central terminal

A Raspberry Pi or Linux PC serves as the central system. It handles:

  • Receiving scan events
  • Storing and evaluating visits
  • Personalising fobs
  • Visualising the ongoing rally
  • Daily statistics and the prize draw

API concept

The central application provides simple endpoints for the scanners:

  • Report a tag scanned at a station
  • Retrieve a tag's progress
  • Optionally retrieve the name or status of a personalised tag

Each ESP can therefore be designed independently, as long as it uses the defined endpoints.

Personalisation

An NFC fob can optionally be personalised at the terminal at any time:

  • Name
  • Email address
  • Optional consent to a newsletter

Personalisation is voluntary. A fob can still be used for the rally without it.

Visualisation

A clearly visible live visualisation at the terminal is a central element.

Visual concept

  • Each stand is represented as a larger bubble or liquid droplet.
  • Each active NFC tag appears as a small droplet.
  • After a scan, the droplet moves towards the corresponding stand's bubble.
  • When a visitor scans the next stand, the droplet moves on.
  • The more stations visited, the larger the droplet becomes.
  • If the last scan was some time ago, the droplet visually separates from the bubble again or fades.

Effect

The visualisation should:

  • Attract attention
  • Make activity at the event visible
  • Make the current rally progress understandable
  • Be interesting technically and aesthetically

Game mechanics

Basic principle

  • Visitors collect scans at several stands.
  • With only a few stands, the goal can be to visit all of them.
  • With many stands, the goal can be defined flexibly, for example visiting 6 out of 10 stations.

Prize draw

  • At the end, all visitors who have visited the required number of stations enter a prize draw.
  • Eligibility is evaluated automatically from the collected scan events.

Additional benefits for Node-K

The NFC fob can be used beyond the event:

  • Visitors can scan it again later at Node-K's association premises.
  • On a first visit to the association, the scan could serve as a voucher for a free drink.

This creates a direct connection between the event and a later visit to the hackerspace.

Evaluation and statistics

At the end of the event day, the system can automatically display statistics such as:

  • Most-visited stands
  • Number of active fobs
  • Number of completed rally entries
  • Movement patterns between stations
  • Number of personalised tags

These data can be used both to review the event and to reuse the concept at future events.

Project benefits

The concept combines several aspects that represent the hackerspace well:

  • NFC technology
  • ESP and embedded development
  • 3D printing
  • Creative hardware design
  • Network communication
  • Web APIs
  • Live visualisation
  • Community interaction

The project is also modular: the central infrastructure is standardised, while the individual scanners can deliberately be designed in individual and creative ways.

Summary

Node-K is organising an interactive NFC rally for LinuxTag Villach 2026. Visitors receive a 3D-printed NFC key fob that they can scan at different stands. The scan stations use individually designed ESP devices that send events to a central terminal. The data are visualised live there, optionally personalised and evaluated for a prize draw. Visitors keep the fob as a giveaway and may even be able to use it for a bonus on their first visit to the hackerspace.

Addition for our own stand

At our own stand, we can also demonstrate other things that can be built and implemented with an NFC chip. This serves as an introduction to the technology, inspiration for tinkering and an invitation to explore hardware, automation and our own infrastructure.