Most of you know how an NFC tag works. The reader creates an RF field that has enough energy to power the electronics in the tag; when the tag wakes up, two-way communication ensues. We’re accustomed to blank tags that can be reprogrammed, and devices like the Flipper Zero that can emulate a tag. In between those two is [MCUer]’s power-free tag emulator, a board which uses NFC receiver hardware to power a small microcontroller that can run emulation code.
The microcontroller in question is the low-power CW32L010 from Wuhan Xinyuan Semiconductor, a Chinese part with an ARM Cortex M0+ on board. Unfortunately, that’s where the interesting news ends, because all we can glean from the GitHub repository is a PCB layout. Not even a circuit diagram, which we hope is an unintended omission rather than deliberate. It does, however, lend itself to the fostering of ideas, because if this designer can’t furnish a schematic, then perhaps you can. It’s not difficult to make an NFC receiver, so perhaps you can hook one up to a microcontroller and be the one who shares the circuit.
Wonder what kinds of NFC it can emulate. Looked into this project some years ago, which is only for RFID at 125kHz I think but still fascinating https://scanlime.org/2012/12/avr-rfid-optimized-and-ported-to-c/
The emulator currently supports ISO/IEC 15693 emulation with full compatibility for read/write operations, and ISO/IEC 14443A support is in development.
It is an NFC Tag Emulator, so it emulates 13.56MHz tags, not 125KHz ones. The current hardware version is V1.1. I will continue to improve it and release the schematic diagram and Gerber files in due course.
Please carefully watch the video on GitHub. This video uses the mobile app TagInfo to read the content of the tag. As is well known, mobile phones do not have 125KHz RFID hardware. Therefore, it works at 13.56MHz rather than 125KHz.
From the pictures, it looks like the BOM and Gerber can already be generated, at least in draft form. Is there a reason not to check them in as a baseline?
The current version only supports simulating one Tag. The next version will add a button and a three-color LED to switch between multiple Tags. Once the firmware for simulating the 14443A Tag is completed, the BOM and Gerber files will be released together.
Shame, there don’t seem to be schematics or firmware for any of their projects which would suggest it’s a deliberate omission.
If you want a less capable dynamic tag I recommend this one:
https://regnerischernachmittag.wordpress.com/2014/08/22/m24sr-arduino-library/
The current hardware version is V1.1. I will continue to improve it and release the schematic diagram and Gerber files in due course.
Depends on what you need to do. SeQR makes QR code tags for luggage, keys, pets etc. You put the info you want the finder to see on your web log in. They can contact you worldwide to notify you.
https://app.seqrcontact.com/
Note: I am not a salesman for them…
https://github.com/NFC-funs/Power-free-NFC-Tag-Emulator
The emulator currently supports ISO/IEC 15693 emulation with full compatibility for read/write operations, and ISO/IEC 14443A support is in development.
Do you plan to release firmware, schematics and gerber files?
When I finish the ISO-14443A part, I think I will release it.