OnAirDecode NFC / RFID 13.56 MHz with an SDR
NFC / RFID 13.56 MHz: ISO 14443 A/B and ISO 15693 frames, tag UIDs and NDEF (receive only, nothing cloned).
- Group
- IoT & sensors
- In the mode list
- Contactless, 13.56 MHz
What NFC / RFID 13.56 MHz is
NFC / RFID at 13.56 MHz, receive only: ISO/IEC 14443 Type A (REQA/WUPA, ATQA, anticollision, SELECT, SAK, UID sizes, CRC_A, HLTA, RATS/ATS, APDU framing as hex, NDEF text/URI from Type 2 READ answers), Type B (REQB/ATQB on the BPSK subcarrier) and ISO/IEC 15693 (1-of-4 / 1-of-256 pulse position, inventory, UID, system info) as far as the public specs allow. Reader frames are 100%% ASK Miller….
Frequencies and settings
OnAir takes any frequency you type; the numbers above are the mode's starting point and the range its table describes. In the app the shortcut label is Contactless, 13.56 MHz.
What OnAir shows
NFC / RFID at 13.56 MHz, receive only: ISO/IEC 14443 Type A (REQA/WUPA, ATQA, anticollision, SELECT, SAK, UID sizes, CRC_A, HLTA, RATS/ATS, APDU framing as hex, NDEF text/URI from Type 2 READ answers), Type B (REQB/ATQB on the BPSK subcarrier) and ISO/IEC 15693 (1-of-4 / 1-of-256 pulse position, inventory, UID, system info) as far as the public specs allow. Reader frames are 100%% ASK Miller; tag answers load-modulate the 847.5 kHz (14443) or 423.75 kHz (15693) subcarrier. Needs an HF-capable receiver (RTL-SDR V4 direct HF, HackRF, Airspy HF+, RX888) at a few Msps so the +-847.5 kHz sidebands fit. Nothing is cloned, no encrypted content is decoded, no keys are attacked. Pet microchips are 134.2 kHz FDX-B, a different band (see docs/NFC.md).
Limits and what it was checked with
Checked with generated signals and impairments; recordings of real signals welcome.
Which radio you need
This is a shortwave mode, so the radio has to tune HF. An SDRplay, Airspy HF+ or an RTL-SDR in direct-sampling mode do that directly; with a HackRF an HF upconverter or a direct-sampling receiver is the usual route. A long wire or loop antenna matters more than the radio.
Receiving and the law
Questions about NFC / RFID 13.56 MHz
Can I decode NFC / RFID 13.56 MHz with an RTL-SDR?
An RTL-SDR can receive HF only in direct-sampling mode, which OnAir offers in its radio settings; results depend on the antenna. SDRplay and Airspy HF+ radios are better suited.
Is it legal to receive NFC / RFID 13.56 MHz?
This mode is passive. It only receives, never connects, pairs or joins networks, and never decrypts payloads. Check the rules where you live.
Can I try NFC / RFID 13.56 MHz in OnAir without a radio?
Yes. Most modes include a built-in synthetic test signal, so you can open the screen and try the controls before you own a radio.