Make: Checkin

A card tap check-in kiosk for MIT makerspaces. Runs on a Raspberry Pi with a touchscreen and a USB HID card reader. Users tap their MIT ID card, the system resolves it to their Kerberos ID via the MIT Card API, and records a check-in or check-out session in Airtable.

This replaces Airtable-Card-Checkin, the original prototype version of card tap check-in for MIT makerspaces.

How it works

1. The kiosk shows a welcome screen and waits for a card tap.
2. A card tap is read by the USB HID card reader, which sends card data to the app via simulated keyboard input (ending with Enter).
3. The app calls the MIT Card API to convert the raw card ID to a Kerberos username.
4. If the user has no open session in Airtable, they are shown a brief survey question (e.g., "What brings you here today?") and checked in.
5. If the user already has an open session, they are checked out immediately.
6. All sessions are recorded in Airtable with the linked maker record, makerspace, survey response, and check-out timestamp.

Hardware and Software Setup

For the complete hardware bill of materials, assembly, OS installation, and software configuration for the standard Raspberry Pi 4 kiosk, see:

SETUP-RASPBERRY-PI.md

Configuration

Each kiosk requires a config.py file that is not tracked in this repository. Create it by copying config-example.py:

cp config-example.py config.py

Then fill in the values for your specific kiosk deployment.

secrets — API credentials

Key	Description
airtable_pat	Airtable Personal Access Token for the Making at MIT base
people_client_id	MIT People API Client ID
people_client_secret	MIT People API Client Secret
card_client_id	MIT Card API Client ID (OAuth2 client credentials)
card_client_secret	MIT Card API Client Secret

site — Location settings

Key	Description
title	Makerspace display name shown on the check-in screen
name	Makerspace name exactly as it appears in Airtable
description	Short description shown on the check-in screen
color-1	Primary theme color (hex, e.g. #57b99d)
color-2	Secondary/dark theme color (hex)

The name field must match the makerspace record name in Airtable exactly — it is used to look up the Airtable record ID at startup.

question — Check-in survey

Key	Description
question	Survey question shown at check-in
answers	List of answer button labels shown to the user

The survey appears after a card tap for a new check-in and times out after 10 seconds, recording 'na' if no answer is selected.

logs

Key	Description
logfile	Absolute path to log file; leave empty string to disable file logging

Running

Install the one required dependency:

pip install --break-system-packages -r requirements.txt

Run the app:

# Cypress Wedge card reader (outputs keystrokes like a keyboard)
python make-checkin.py

# HID Omnikey card reader (raw binary card data — standard deployed configuration)
python make-checkin.py -H

On a deployed kiosk the app is launched automatically via a systemd service and restarts automatically if it exits. See SETUP-RASPBERRY-PI.md for full details.

Known Issues and Needed Enhancements

1. Sometimes stuck on "One moment..." screen — possibly triggered by invalid card data or a momentary network loss
2. Ignoring the follow-up survey question will block the kiosk until someone selects an answer; it should time out and complete the check-in with 'na'
3. Better error handling, health monitoring, and recovery — most errors and blocking states are silent or only logged in the background; consider a watchdog timer for automatic restart
4. Network status and API reachability are not surfaced to the user; should show an indicator if offline and retry connections periodically
5. A failure response from the MIT Card API should be shown to the user, including the card token that was read and the API error code
6. Performance is slow — likely improvable with more compact API calls, fewer open-ended Airtable searches, and local caching of maker records
7. Only MIT IDs are supported currently; should fall back to a registered MiFare tap ID in Airtable when MIT ID lookup fails
8. Input buffer may not be cleared before reading the next card tap
9. Better idle screen and button graphics
10. Consider switching to landscape orientation; portrait mode requires display rotation configuration with no functional advantage
11. Fullscreen mode currently requires X11 — update to support fullscreen under Wayland to simplify OS configuration
12. Investigate whether there is a touch input event library available for Tkinter
13. Consider switching to guizero (a simplified wrapper over Tkinter) for easier maintenance