Unattended iPad kiosk with Bluetooth thermal printing

Healthcare

Industry: Healthcare

Platform: iOS (iPad kiosk)

Stack: Swift · SwiftUI · Epson ePOS SDK · CoreBluetooth · Moya · Combine

Description: Wall-mounted iPad kiosk with Bluetooth thermal printing and self-healing auth middleware.

---

The engineering surface was embedded-systems integration disguised as a mobile app: unattended kiosk hardening, a strict-lifecycle Bluetooth printer SDK that silently fails on out-of-order calls, SwiftUI views rasterized to monochrome dithered bitmaps for thermal output, and a three-step authentication pipeline with transparent middleware-driven token refresh. Every error path needed an explicit recovery route; a kiosk cannot assume a user will force-quit and relaunch. Idle timers, navigation unwind, and notification-driven login resets eliminated dead ends.

We owned the full iPad client — navigation state machine, printer lifecycle wrapper, token middleware, and the bitmap rendering pipeline. The client owned the appointment-management backend and the device-management deployment.

Engagement: ~3-month build · single iOS specialist · 2024.

Engineering signal: sub-3-second Bluetooth discovery-to-print across full-business-day continuous operation; zero force-quit-and-relaunch requirements over 10+ hour shifts.