Design and Implementation of Hotel Self‑Check‑in Kiosk Architecture

Since 2014, the author has worked on Android client development and now focuses on self‑check‑in kiosk development for hotels, aiming to improve guest experience.

Introduction

Self‑service kiosks are becoming common in banks, airports, cinemas, hospitals, and hotels, offering fast, low‑cost, 24‑hour check‑in/out without queues, reducing front‑desk workload.

Traditional Check‑in/Check‑out Process

Guests present ID at the front desk, staff query the PMS, assign rooms, issue key cards and registration slips; check‑out involves returning the key card.

Guests are unaware of back‑office operations; room changes require staff interaction.

Self‑Check‑in Business Process

Guests must now perform the front‑desk tasks themselves: scan ID, confirm orders, add guests, pay, collect key cards and registration slips.

Kiosk Architecture Evolution

Key components include the user interface, hotel PMS, PSB, ID scanner, card‑issuing machine, and printer.

Windows Version

Runs on Windows 7, connects to PMS, PSB, and peripherals; advantages: mature drivers and easy implementation; disadvantages: poor touch UI experience.

Android Version

Provides a touch‑friendly UI similar to mobile apps; however, many hardware drivers are Windows‑only, limiting applicability.

Dual‑Board (Android + Windows)

Two motherboards: Android handles UI, Windows handles PMS, PSB, and hardware via a local server; improves UX but increases system complexity and maintenance cost.

ID Scanner

The scanner reads personal data (name, ID number, birthdate, expiry, photo). The vendor provides commands to open port, search card, read data; card search must be polled.

Card‑Issuing Machine Process

Two types: non‑circulating and circulating; both read/write contactless cards. The workflow includes card storage, write area, ejection slot, recycle bin, and sensors.

Card‑Issuing Commands

Key commands: reset, status query, special card, set ejection slot, etc. Example of non‑circulating CRT‑571 commands is shown.

Example command sent:

F2 00 00 03 43 31 30 03 B0

Explanation: F2 start, 00 address, 00 03 length, 43 command header, 31 30 query status, 03 end, B0 checksum.

Response received:

F2 00 00 06 50 31 30 30 31 30 03 97

Interpretation: 50 success, 31 30 returned command, 30 31 30 status bits (st0, st1, st2).

Printer Business Process

The thermal printer (58 mm width, 48 mm printable) supports GB18030, QR codes, barcodes, and real‑time status. It can print via driver (file) or direct serial commands.

Printing flow: open serial port, initialize, set charset, check paper, set format, then print line by line.

Hardware Monitoring

Monitors ID scanner success, card‑machine status (port open, status query, card availability, recycle bin fullness, card jam), and printer paper presence.

Door Card Writing Scheme

Different lock manufacturers require separate read/write/erase interfaces; three generic interfaces are provided to handle diverse lock types.

Kiosk Network Deployment

Hotel internal network (no Internet) hosts PMS; external network accesses cloud services; PSB uses a dedicated network for police system uploads. Multi‑NIC solutions connect Windows to internal, external, and PSB networks, while Android uses a single NIC.

Bridge solutions connect a single Windows NIC to Android via crossover cable when internal/external networks are not separated.

The overall goal is to enable guests to complete check‑in by scanning ID and receiving a key card and registration slip, while other reservation steps are handled online.