A smart, modular system for managing and tracking access to shared resources

Josué A. Bouchard

CET 4370C Advanced Programming Applications

Presentation overview

The problem
The solution
PiLock's architecture
Hardware and Software
Demo time

The shared workspace problem

Hard to control who uses shared items.
No automatic way to ensure items are returned.
Requires a supervisor to be present or reachable.

The Student Development Golf Cart Keys

A log must be filled each time the golf cart is used
The log is necessary to keep accountability and comply with Valencia College regulations
If the supervisor is not present, there needs to be a trust that the protocol will be respected
High pressure moments come -> Speed or protocol?

Why do we have to choose only one?

Access control for trusted users
Logging of every open/close event
Accountability without needing a supervisor

Manager Web Server

Web Interface server
- See, create, and edit the tags
- See and download the logs

Controller API
- Validates tags from the Controller Software and creates log records

Web Interface Server

@tag_router.get("/", name="tags:index-ui")
def tag_index_ui(request: Request, session: SessionDep):
    tags = get_tags(session)
    return templates.TemplateResponse(
        request,
        name="tags/index.jinja",
        context={"tags": tags},
    )

def get_tags(session: Session) -> Iterable[Tag]:
    return session.exec(select(Tag)).all()

SessionDep = Annotated[Session, Depends(_get_session_aux)]

Controller API

@app.get("/access/check")
def check_access(tag_uid: str, session: SessionDep):
    maybe_tag = repository.get_tag_by_tag_uid(tag_uid, session)
    is_access_granted = maybe_tag is not None
    maybe_person_information = maybe_tag and maybe_tag.person_information()

    access_log = repository.create_access_log(
        tag_uid=tag_uid,
        access_was_granted=is_access_granted,
        person_information=maybe_person_information,
        session=session,
    )

    return access_log

Manager Web Server

Data models

Controller Software

Interfaces with with the Raspberry Pi hardware
Calls the Controller API to validate tags
Manages the NFC sensor and the servo

Controller Software

Hardware and Software

Raspberry Pi 4B
RC522 NFC sensor
SG90 microservo

CPython 3.13
uv
PiGPIOd
Systemd
Journald

Hardware

Software

Demo Time

Conclussion

PiLock addresses a practical problem faced in shared workspaces: ensuring that valuable resources can be accessed quickly by trusted users while still maintaining accountability

It taught me about Python web programming, how to interface with GPIO pins in a Linux environment, how Python sometimes interfaces with C++ and raw memory addresses, and integration between systems.

A smart, modular system for managing and tracking access to shared resources

Josué A. Bouchard

CET 4370C Advanced Programming Applications

References (1/4)

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D. Temoshok et al., “Digital Identity Guidelines,” Gaithersburg, MD, technical report NIST SP 800-63-4, Aug. 2025. doi: 10.6028/NIST.SP.800-63-4.

References (2/4)

NXP Semiconductors, “MFRC522 - Standard performance MIFARE and NTAG frontend,” Apr. 2016. [Online]. Available: https://www.nxp.com/docs/en/data-sheet/MFRC522.pdf

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“Datasheet - Raspberry Pi 4 Model B.” Accessed: Nov. 19, 2025. [Online]. Available: https://datasheets.raspberrypi.com/rpi4/raspberry-pi-4-datasheet.pdf

References (3/4)

“QCon London: Meta Used Monolithic Architecture to Ship Threads in Only Five Months.” Accessed: Sept. 30, 2025. [Online]. Available: https://www.infoq.com/news/2024/04/meta-threads-instagram-5-months/

G. van Rossum, J. Lehtosalo, and Ł. Langa, “PEP 484 - Type Hints.” Accessed: Nov. 21, 2025. [Online]. Available: https://peps.python.org/pep-0484/

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“FastAPI.” Accessed: Sept. 30, 2025. [Online]. Available: https://fastapi.tiangolo.com/

Astral, “uv.” [Online]. Available: https://docs.astral.sh/uv/

References (4/4)

Oloruntoba, Samuel, Walia, Anish Singh, and Kurup, Manikandan, “SOLID Design Principles Explained: Building Better Software Architecture.” Accessed: Nov. 19, 2025. [Online]. Available: https://www.digitalocean.com/community/conceptual-articles/s-o-l-i-d-the-first-five-principles-of-object-oriented-design

“JWTs vs. sessions: which authentication approach is right for you?.” Accessed: Sept. 30, 2025. [Online]. Available: https://stytch.com/blog/jwts-vs-sessions-which-is-right-for-you/

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