NFC Canary

NFC scanner detection and alerter for when you're concerned about others coming up and sniffing around your pockets, bags and gear. It's a passive 13.56 MHz reader detector for Flipper Zero.

How to use:

• Carry it in a pocket and if someone attempts to sniff your wallet or gear an alarm will go off
• Put it inside your backpack to record how many things tried to NFC scan your bag in an airport
• Any use you can think of where you want to know if someone or something is trying to scan you at 13.56MHz

How does it work

Uses the ST25R3916's hardware External Field Detector: it listens for a reader's carrier and never transmits anything of its own.

Detects readers, not tags. A card, badge, or fob will never trigger this because passive tags have no transmitter. You need something that emits/energizes a tag like a phone with NFC on (unlocked), or a payment/access terminal. Present it to the back of the Flipper.

Armed	Reader detected

Event log	Settings

Install

From a release: download nfc_canary.fap from Releases and copy it to /ext/apps/NFC/ on the Flipper's SD card (qFlipper's file manager works). Then: Apps → NFC → NFC Canary.

From source: see Build and deploy.

Quick start

1. Launch the app — the first run explains the tag-vs-reader distinction.
2. Press OK → OK to audition the alert so you know what to listen and feel for.
3. Press Back to arm it, and pocket the device.

To confirm it works, hold an unlocked Android phone with NFC enabled against the back of the Flipper. Full procedure: docs/TESTING.md.

Build and deploy

./deploy.sh                # auto-detects the Flipper's serial port
./deploy.sh /dev/ttyACM0   # or name it

Then: Apps > NFC > NFC Canary