Turn a Raspberry Pi into a transfer box between a Windows PC and a USB flash drive, where every copy is verified before it says "done".

 Windows PC                          Raspberry Pi                    USB flash drive
 FileZilla Server  ── Ethernet ──    PiLink on screen + keyboard ── USB ──  the stick

What problem it solves

Some PCs must never have a USB stick plugged into them: lab and test-bench machines, shop-floor PCs, anything under an IT policy that blocks removable media. Files still have to move between those PCs and sticks. PiLink puts a Raspberry Pi in the middle. The PC only talks FTP over one cable; the stick only ever touches the Pi.

The usual way	What goes wrong	PiLink
Plug the stick into the PC	Not allowed, or a malware/data-leak risk	The stick never touches the PC. The PC only serves files over FTP (or FTPS) on a direct cable
Copy, see the progress bar finish, pull the stick	Data still in the write cache is lost; a failing stick returns different bytes	Every file is fsync'd to the stick, read back and checksummed before PiLink says done. "Safely remove" flushes and unmounts
Someone has to know Linux	Errors are tracebacks	Numbered keys on a blue screen, a file picker, and every error is a sentence that says what to check
"Did that work last Tuesday?"	Nobody knows	A history of every transfer, failed ones included, and a checksums.txt next to every copy

Screens

A transfer shows each step, the bytes, speed and time left. Esc cancels.	Done only appears after every file was read back and compared.
Flash → Computer lets you pick files and folders (Space), never system folders.	History of every transfer, including the ones that failed and why.

Diagnostics (key 5, or pilink doctor over SSH) checks the folders, the stick, the cable and the FTP login, and says what to do about anything that fails.

Try it without a Pi

pip install "pilink[demo] @ git+https://github.com/Alifizz01/PiLink"
pilink demo

The demo starts a local FTP server playing the PC, a folder playing the stick, and sample files on both, then opens the real UI. Everything stays inside one temp folder. It is also what produced every screenshot above (tools/screenshots.py).

Install on a Raspberry Pi

sudo git clone https://github.com/Alifizz01/PiLink /opt/pilink
sudo /opt/pilink/scripts/setup_pi.sh --static-ip 192.168.50.2/24     # Lite or Desktop is detected
sudo nano /etc/pilink.yaml                                           # the FileZilla user and folders
pilink doctor

Two ways to run it, chosen with --mode (or detected automatically):

	Raspberry Pi OS Lite	Raspberry Pi OS with desktop
PiLink appears	full screen on the console from boot, like an appliance	in a window at login, and in Menu → Accessories
The stick is mounted by	PiLink's udev rule, at /mnt/flash	the desktop, as usual; PiLink finds it (flash_mount: "auto")
Safely remove uses	a sudoers entry allowing only that unmount	udisksctl, the same as the desktop's eject button

The full walkthrough, including the FileZilla Server settings on the PC (users, folders, TLS, firewall), is in docs/SETUP.md. When something does not connect: docs/TROUBLESHOOTING.md.

Using it

key
1	Computer → Flash drive. Everything in the PC's share is downloaded, written to transfers/<date-time>/ on the stick, read back and verified, with checksums.txt
2	Flash drive → Computer. Pick files/folders; they arrive in uploads/<date-time>/ on the PC (never overwriting an earlier upload), every size checked on the PC
3	Safely remove the stick
4 / 5	History / Diagnostics

Everything is also a command, for SSH or scripts: pilink status, pilink pc-to-flash, pilink flash-to-pc Measurements report.pdf, pilink eject, pilink history, pilink doctor.

How it is built and tested

• Python + Textual for the console UI; standard-library ftplib for FTP and explicit FTPS (FileZilla Server 1.x requires TLS by default).
• Checked at every step: the stick must really be mounted (otherwise files would land on the SD card), free space is checked against the real total, sizes are checked against the server's listing, hashes are compared after reading the stick back, uploads are confirmed with SIZE.
• 18 tests run both workflows end to end against a real FTP server (pyftpdlib) and cover the failure cases: wrong password, unreachable PC, a dropped connection, no stick, full stick, a byte corrupted on the stick, cancel, bad config, desktop automount. One test drives the real UI headless with key presses. CI runs them on Python 3.9, 3.11 (Bookworm's) and 3.12.

How the pieces fit: docs/architecture.md.

Upgrading from the 2025 version

Rerun setup_pi.sh. Your /etc/pilink.yaml keeps working (retired sections are ignored), the old pilink-usb-watcher service is removed (it copied every transfer a second time), and the service now runs as your real user instead of the pi account that current Raspberry Pi OS no longer has. If FileZilla Server is 1.x, add tls: true to the endpoint.

License

MIT · © Muhamad Alif Izzuwan Bin Ibrahim