Improve NFC sniffer (PCD/PICC) ISO/IEC 14443A

[bvernoux]

Actual code provide basic low level sniffer for (PCD/PICC) ISO/IEC 14443A when using dnfc2 => sniff command
T_SNIFF (Test special sniffer ST25R3916 MCU_CLK(PA5) and CSI CSO)
It requires a Logic Analyzer or an Oscilloscope to capture the binary data then user's shall do manual decode of the PCD / PICC bit to final data.
Logic Analyzer Setup:
Capture trigger on Channel 0 (CSO) on rising edge

• Channel 0 / HydraNFC v2 ST25R3916 CSO pin corresponding to ST29R3916 Digital Demodulation
  (Show Reader/Tag)
• Channel 1 / ST25R3916 CLK/PA5 (configured at 3.39MHz based on HydraNFC v2 clock 27.12MHz)

Setup example

Example capture and "manual" decoding
DSView with DSLogic U3Pro16 capture of a Mifare Classic 4K

Picoscope capture of a Mifare Classic 1K

Any contribution is welcome for the decoder to be embedded in Firmware or done externally on PC or even better by writing a dedicated PulseView/DSView decoder

[gurujustin]

Is there sniffer mode in this code?

[bvernoux]

So far the sniffer code for ISO14443A is not finished (so this issue will remain open until it is implemented and fully working)
See https://github.com/hydrabus/hydrafw_hydranfc_shield_v2/wiki/HydraFW-HydraNFC-v2-guide-dnfc-mode#todo

• Waiting for contribution (No contribution since 2020...) for the ISO14443A embedded sniffer with decoder or DSView/PulseView decoder, the sniffer (dnfc2 => sniff command) is fully working with a Logic Analyzer / Oscilloscope but decoding shall be done manually today

Alternative way (low level requires oscilloscope/logic analyzer) to sniff any protocol (raw mode) is to use dnfc mode with command set-nfc-obsv
See https://github.com/hydrabus/hydrafw_hydranfc_shield_v2/wiki/HydraFW-HydraNFC-v2-guide-dnfc-mode#debugdeveloper-mode-for-nfc-shield-v2-with-dnfc-mode-spi-low-level see "Analog Test and Observation Register 1 (Test Output CSI/CSO)"

I can provide more details in private if you are interested in this alternative low level (requiring oscilloscope/logic analyer) until the sniffer code for ISO14443A is available

• Contact me bvernoux@hydrabus.com if you want more details

[gurujustin]

could you explain in more detail?

[bvernoux]

Please contact me by Email bvernoux@hydrabus.com (and provide details where/when you have bought HydraNFC v2 + HydraBus) I do not want to provide support about that in an issue as it is very technical and requires hardware (oscilloscope/logic analyzer HydraBus+HydraNFC v2) and knowledge on ST25R3916