NFC project- Blocker tag

[dmaaaan]

Hi everyone,

Id like to know if anyone has tried to implement NFC Blocker Tag on NRF52480 or any similar nRF5 chip using their SDK.
In general the purpose is to block a NFC ISO 14443-4 communication between a reader and a NFC tag that we want to protect.
To do that we want to have a program on the NRF52480 dongle that will send a large number of IDs whenever a new request is sent by the reader. This is supposed to prevent the protected tag from being selected by the reader.
We would have to modify the already existing NFC library and possibly switch off the anticollision mode.
The problem is that the library with all the low-level functions that implement the actual communication is compiled so we cant modify it. Only the HAL functions are modifiable but are of no use to us.

Has anyone done a NFC communication from the scratch for this family of chips that we could reuse for our project?
Alternatively if you had some tipps on how to easily write our own custom NFC interrupt in main.c we would be grateful.

Thx in advance for your help.

[Andreas]

Hi,

 

You might be able to do that with a fairly normal NFC implementation that might write just some arbitrary data to the reader, as the nRF52840 tag will degrade the mutual coupling between the reader antenna and the antenna in the rag that you want to protect. In other words acting as sort of a jammer. In any case your mileage may vary, you just have to try it out, as the nRF52840 tag implementation is not intended for such use. 

 

Best regards,

Andreas