~/ work / cashless-nfc cashless NFC · ruggedised Android · payments
Wristbands as wallets,
tap to pay.
Trainspot KK · for the Pommery champagne house
A cashless mobile payment app deployed at the Pommery champagne house. Visitors top up their NFC wristband on entry, then tap at bars and stations to spend the pre-loaded credit. The Android client runs on ruggedised Famoco handhelds.
// context
A premium event payment flow has to survive outdoor humidity, work with staff who never look at the screen, and resist casual cloning of the wristbands. Off-the-shelf cashless terminals at this scale either lock the operator into a closed processor or cut corners on chip-level security.
// our role
Mobile and embedded engineering for the Trainspot KK team: custom Android client on Famoco ruggedised handhelds, NXP UltraLight C personalisation with per-card 3DES key diversification, counter-based dual-buffer atomic transactions so a power loss mid-write never corrupts a balance, and native JNI handling of the master keys to keep them out of the Java heap.
// stack
- Android (Kotlin)
- NXP UltraLight C
- 3DES
- TapLinx
- JNI / native-C
- Famoco
// outcome
Cashless payments in production at the Pommery champagne house, operated by the Trainspot KK team on Famoco handhelds.
// links
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