// the find
ieatlint/SWipe
Magnetic stripe decoder using an audio interface
SWipe reads magnetic stripe cards by treating a Square-style audio dongle as a microphone input, decoding the analog signal in software. It's a hardware hacking tool for developers curious about mag stripe internals, not a production card reader. Last touched in 2015.
The core signal decoding logic (mslib.c) is a self-contained C implementation of the IATA mag stripe standard — useful as a reference even if you never run the app. Qt Multimedia makes the audio capture cross-platform without much ceremony. The Square dongle as input is clever hardware reuse — those dongles are cheap and widely available.
Dead project — 11 years of silence, Qt 4.6 requirement is ancient (Qt 6 is current), and building this today will be a fight with deprecated APIs. No test data or sample captures included, so debugging the decoder blind is painful. The README is four sentences with a dead blog link. PCI-DSS and modern card security make the actual attack surface here largely obsolete — EMV chip and tap have made Track 1/2 far less useful.