It’s already good enough for a PR, but I’ll try to make it even better.

When debugging LF RFID protocols on the #ChameleonUltra, you often need to answer a basic question: is the field actually doing what the firmware thinks it is? For reader-talk-first protocols like #EM4305, the entire exchange depends on gap-encoded commands being sent correctly into the field. Without a way to observe the field directly, a firmware bug that silently prevents gaps from being sent looks identical to a tag that isn't responding, both produce LF tag not found.
The #ProxMark3 has lf sniff and a full suite of data analysis commands for exactly this reason. These commands bring the same capability to the ChameleonUltra, using the SAADC already present on the #nRF52840 to sample the antenna field at 125kHz.
PR: EM4x05/EM4x69 LF Reader for #ChameleonUltra
I’ve been working on adding support for reading EM4x05 and EM4x69 tags, the reader-talk-first (RTF) 125kHz protocol used in some access control cards, parking fobs, and animal microchips.
What’s implemented:
∙ lf em 4x05 read, reads config, UID and detects EM4x69 64-bit UIDs
∙ Automatic UID block detection via LWR field (works in EM UNIQUE/PAXTON mode)
∙ Gap encoding infrastructure (lf_gap.h/c) used to send RTF commands
∙ PSK demodulator bug fixes (3 bugs fixed)
Current status:
The command works (clean timeout, no crashes) but haven’t confirmed a successful read from a real EM4x05/EM4x69 tag yet. Hardware testing has been the bottleneck, T5577 cards can’t emulate RTF protocol.
How you can help:
∙ Have an EM4x05, EM4x69, or EM4305 tag? Flash the PR build and run lf em 4x05 read, make sure RTF is enabled on the tag first (lf em 4x05 info on PM3 should show “R.T.F. Reader talk first enabled”)
∙ Have a logic analyser? Capture the LF field while running lf em 4x05 read and check if the gap command is being sent correctly
∙ Know the EM4x05 protocol well? Review the timing and gap encoding in lf_em4x05_data.c and lf_gap.h
PR: https://github.com/RfidResearchGroup/ChameleonUltra/pull/386

The new generation chameleon based on NRF52840 makes the performance of card emulation more stable. And gave the chameleon the ability to read, write, and decrypt cards. - add EM4X05 (read)support for CU by nieldk · Pull Request #386 · RfidResearchGroup/ChameleonUltra
Paljude kaardivahedega rahakott: Mitme kaardipesaga RFID rahakott.
Elegantne RFID turvaline rahakott, mahutab kuni 36 kaarti. Ideaalne reisidel ja igapäevaseks kasutamiseks. Telli nüüd! https://tootemaailm.ee/paljude-kaardivahedega-rahakott/ #rahakott #RFID #turvalisus #reisid #kaardivahed
Индуктивная связь
Сейчас беспроводными технологиями передачи данных никого не удивишь. На том же Али море различных модулей для беспроводной связи на любой вкус и цвет начиная от WiFi заканчивая NFC и RFID. Однако, в некоторых изделиях, по разным причинам, применение спец микросхем/модулей беспроводной передачи данных может быть нежелательно. Эта статья о том, как можно c помощью дросселя и нескольких транзисторов реализовать беспроводный интерфейс малого радиуса действия для микроконтроллера.
https://habr.com/ru/articles/1008538/
#беспроводная_связь #микроконтроллеры #pic #трансивер #uart #rfid #nfc #diy #дроссель