Serial Transfer

A file-transfer dashboard that makes connection, block delivery, acknowledgement and verification visible. Sender and receiver use labels that match their own progress.

Run it

Build the examples with devenv shell -- lcom-ng-build, then run:

lcom-ng run-pair build/examples/serial_transfer send \
  --right build/examples/serial_transfer receive

Try a complete workflow

Start the pair to transfer a sprite automatically. Enable Keep open with Space to inspect the result. Run the fault demo to see a dropped frame retried, or the CRC demo to see a failed verification.

Controls

• Space: keep the result open. F1: help.
• Esc or Cmd/Ctrl+W: close the peer.

Command shortcuts work on macOS; Ctrl shortcuts work on other hosts. Esc closes help first. Cmd/Ctrl+W closes the app.

In the app

These are actual runtime captures. Open a screenshot for a larger view; use Left and Right to browse, and Escape to close.

Ready to transferThe sender has prepared the sprite and starts its acknowledged block transfer.

One block at a timeThe receiver fills in only bytes it has actually received.

Recovering a lost frameFault mode drops one frame. The sender waits, then retries it.

Verified deliveryThe final CRC32 matches on both peers.

A complete received spriteAll 32 blocks are present and the result is verified.

A precise failure stateA deliberately bad CRC leaves an unverified transfer and a clear failure heading.

Inspect the transferF1 opens help. Space keeps the result visible after completion.

1 / 7

Ready to transfer · The sender has prepared the sprite and starts its acknowledged block transfer.

What it demonstrates

UART negotiation, framed messages, block indices, checksums, acknowledgements, retry deadlines and terminal error states.

The example transfers its built-in 16 × 16 indexed sprite. A progress bar reaching 100% alone does not mean delivery is verified; the final CRC result does.

Source: examples/serial_transfer.c.

Refresh these screenshots

devenv shell -- python3 scripts/capture_gallery.py --app serial-transfer

See the screenshot workflow to add states or check freshness.