QR-log Bridge

QR-log Bridge is a local-first transfer system that moves files, logs, and diagnostic information by scanning a stream of QR codes. It is built for situations where AirDrop, cloud storage, shared folders, VPN tunnels, or direct network links are not available or not desirable.

The sender splits the source data into compact protocol frames and renders them as a high-density QR stream. The iPhone or iPad scans the stream, reconstructs the payload locally, and verifies the result with integrity checks.

The current preview GIFs on the website include mini.gif, medium.gif, 2x2.gif, and 25fps.gif. They are intended to test normal live scanning, 2x2 QR grid scanning, and Video Decode from a recorded QR stream.

Why It Exists

QR-log Bridge is especially useful when a support case must be prepared without relying on a permanent diagnostics connection between a device and the manufacturer's support organization.

In medical device environments, that can mean:

• no internet access on the device
• no VPN connection to the manufacturer
• local policy restrictions
• site security rules
• defense-related or regulated network constraints

Instead of waiting for manual extraction with a USB stick or a specialized on-site workflow, the customer can capture diagnostic information directly with a mobile device and transfer it immediately. That shortens the path from issue discovery to support action and increases the chance that the first customer service engineer visit is already well prepared.

Key Features

• QR-based offline file transfer
• iPhone and iPad receiver app
• Up to 200 kbit/s on-the-fly transfer rates depending on payload and scan conditions
• 2x2 QR grid mode for four QR payloads per displayed frame
• Video Decode from Photos or Files for recorded QR streams
• Early rejection of normal videos that do not contain a QR-log transfer
• Optional protocol header with default fallback behavior
• Block-based parity and FEC recovery
• Interleaved replay to improve scan resilience
• CRC32 and SHA-256 integrity checks
• Camera lens selection and zoom control up to 3.0x
• Frame rate toggle between 30 FPS and 60 FPS
• Dedicated received-files sheet with preview, share, and delete actions
• Local debug text export with protocol details and transfer rates
• iPhone and iPad portrait and landscape layouts
• Automatic collapsing of controls and status panels during active use
• Practical fit for service workflows, medical device support, and other constrained environments

How It Works

1. Start the sender on the desktop computer or source system.
2. Open QR-log Bridge on iPhone or iPad.
3. Scan the animated QR stream live, or import a recorded QR stream video.
4. The app reconstructs the original file or diagnostic payload locally.
5. After transfer, you can preview, share, or delete the received file.

Typical Service Flow

1. A technical issue is identified on site.
2. Relevant logs or diagnostic exports are prepared on the source system.
3. The customer or service team scans the QR stream with an iPhone or iPad.
4. The data is transferred without needing a network connection.
5. The customer service engineer receives the information early and can prepare the repair visit more precisely.

Notes

• Camera access is required only for QR scanning.
• The app works offline and does not require an account, cloud service, or permanent pairing.
• Received files are stored locally in the app sandbox.
• Version 1.1.2 testing focuses on Video Decode and 2x2 QR grid scanning.
• A debug text file can be generated after transfer for troubleshooting, validation, and performance analysis.
• The workflow is designed to be practical, inspectable, and easy to test.

Contact

Roland Emrich
emrich.roland@gmail.com