The HydraNFC is an NFC shield hardware (to be plugged on top of HydraBus) to sniff, read/write or emulate any 13.56MHz NFC tags for anyone interested in debugging/hacking/developing for NFC.
It has been designed to be used with HydraBus but can also be used with other MCU.

HydraNFC is as powerful as Proxmark3 hardware (when combined with HydraBus) but smaller, more extensible and without requiring an FPGA (all is done in CortexM4 MCU with the help of HydraBus with ultra fast unique algorithm to sniff & decode in real-time PICC/PCD NFC cards).

For more info on open firmware (HydraBus Required) or hardware for HydraNFC see github:
Update 12 Sept. 2014: The Firmware will be released when HydraBus board will be available (in less than 1 week).

HydraNFC firmware (requires HydraBus) can sniff ISO14443A PICC and PCD both side in realtime without any loss (with an ultra optimized synchronization, LUT and asm optimization and of course with the help of TI TRF7970A special raw mode with data sampled @3.39MHz using SPI slave with DMA circular buffer).

The whole process take less than 1µs with code execution from flash memory (checked with oscilloscope worst case):
1) NFC RX stream synchronization (by counting leading zero or reverse)
2) Downsampling by 4 + filtering of raw data (32bits IN => 8bits OUT for 848KHz)
3) Detection of protocol (Miller Modified/PCD or Manchester/PICC)
4) Conversion of final decoded data PICC or PCD (8bits IN => 1bit OUT) in ASCII hex stored in SRAM with same syntax as proxmark
So there is room to decode/encode any protocol at up to 1MHz (when NFC is limited to 848KHz)
Advantage is also GPIO of STM32F4 can exceed 80MHz, so it is also possible to encode anything at 13.56MHz (limited by NFC) and define/create custom NFC encoder/decoder.


  • Features of the HydraNFC Shield board:
    • Autonomous mode with 4 User buttons and 4 User LEDs.
    • Use HydraBus microSD card to save or load data.
      • Support of microSD (FAT16/FAT32) card up upto 32GB (tested with SanDisk Extreme 32GB).
    • Use Texas Instrument TRF7970A NFC chipset with full access to all pins and all modes of TRF7970A through connectors J1/J2/J3.
    • HydraBus Antenna (external) with U.FL connector (cable included) or SMA (optional) and can read MIFARE card at up to 8cm (with 20cm cable).
    • Hardware documentation is available on github:
    • Hardware licence CC BY NC (for commercial licence contact [email protected]).

Features of the HydraNFC embedded firmware:

  • Virtual Serial Port access through microUSB with VT100 terminal/shell (compatible with any computer supporting USB Virtual Serial port).
    • Usage of ChibiOS (OS+Drivers) and microrl for VT100 terminal with history, completion and lot of other cool features.
  • Basic UID read for Vicinity/ISO15693 (through shell command).
  • Basic UID read for MIFARE One card (through shell command).
  • Sniffer mode in autonomous mode for ISO14443A including both PICC and PCD with data logged to microSD card (tested with success with MIFARE NFC).



Example sniffer mode with terminal output log on a Mifare One card read by Nexus S (data sniffed using HydraBus+HydraNFC):

TAG 04 00
93 70 cd 81 5f 76 65 d1 86
TAG 08 b6 dd
60 00 f5 7b
TAG 2a 81 4c 55
8c cc db f8 cb 98 1a 6e
TAG a0 ed 29 bd
b2 ee f9 09
TAG 76 e6 ca 66 cc e6 0b df 7d 69 31 70 08 f3 6c dd eb ca
3e 3b d5 81
TAG 82 0c df 9e e8 b0 e1 4a c5 9c de 45 27 26 79 41 e7 00
07 c6 2d 8f
TAG fe c0 83 39 40 cb ea d8 0a cf 18 00 6c 78 97 9b 01 95
f8 86 46 1c
TAG 34 d7 71 20 99 a1 a3 f9 0c e6 90 8b e6 5e 93 c1 53 23
ae 87 f6 db
TAG c9 82 dd d5
90 7c 16 4a 00 26 6c b4

  • Planned features:
    • Emulator mode (Card Emulation) is planned and lot of other modes (like raw mode to modulate even proprietary protocol on 13.56MHz).
    • Sniffer mode for ISO14443B and ISO15693 or lot of other mode (raw specific mode) could be also supported in sniffer mode.


More info at


For more info and to get started with your HydraNFC, visit the HydraBus/HydraNFC website and for open firmware (HydraBus Required) or hardware for HydraNFC see github.
If you encounter any problems when using this product, contact the technical support.

HydraNFC Shield plus HydraNFC Antenna

  • Brand: HydraBus
  • Product Code: SEEED-113990077
  • Reward Points: 86
  • Availability: Out Of Stock
  • £103.67

  • Ex Tax: £86.39
  • Price in reward points: 900




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