Space Bar badge app

Tildagon badge app for the Polybius Space Bar at EMF Camp.

Browse the menu, add items to your basket, place an order — the QR code appears on your badge screen. Hold it up to the scanner at the payment terminal.

Setup

1. Install from the badge app store, or copy to your badge manually
2. Make sure your badge is on the EMF camp WiFi
3. Open Space Bar from the Apps menu

How it works

• Orders expire after 2 minutes — the QR is only valid while the countdown is running
• Walk up to the payment terminal, hold your badge up to the scanner
• Soft drinks (no age check needed) auto-charge; alcoholic drinks need staff ID verification
• Once paid, the badge switches to a Processing… screen — the QR closes
• When bar staff mark the order ready, the badge flashes green with COLLECT
• Press B on the QR screen to toggle between the QR code and an order summary (price + ref)
• Press F on the QR screen to cancel the order and go back to the menu

Config (developers)

Edit the constants at the top of app.py:

TILLWEB_BASE_URL = "https://bar.emf.camp"
KIOSK_TOKEN      = "<badge-app-public-token>"
LOCATION         = "Spacebar"          # must match emftillweb.toml token location
LOCATION_DISPLAY = "Space BAR"         # shown in menu header (logo TBD)
OMS_BASE_URL     = "http://<luke-device-ip>:8081"  # must be reachable from badge WiFi

After placing an order the badge polls OMS_BASE_URL/api/orders?order=<ref> every 5 seconds. When the OMS state changes to processing the QR screen closes. When it changes to collect the badge flashes green and pulses the LEDs.

If the OMS is unreachable for 5 consecutive polls the badge shows "Can't reach bar — see staff for order" and stops polling. The order still exists at the till; staff can look it up manually.

Pressing F on the QR screen while the QR is still live cancels the order: the badge POSTs {"order_ref": ..., "barcode": ...} to emftillweb/api/kiosk/orders/cancel.json. The barcode HMAC check digit prevents forgery — only a barcode issued by the server in a real order response is valid.

emftillweb.toml entry

[kiosk.tokens.<public-badge-token>]
locations  = ["Spacebar"]
source     = "badge"
user       = "kiosk"
timeout    = 120        # must match EXPIRY_S in app.py
max_items  = 1          # one drink per badge order
rate_limit = 300        # 5 min between orders per IP

Local dev (badge simulator)

# From the top-level repo root:
dev/sync-badge-sim.sh
cd /tmp/badge-2024-software
python3.10 -u sim/run.py spacebar_badge.SpaceBarApp

See dev/README.md for the full stack (mock till + OMS + sim).