Can we differentiate between a polling device and another with the nRF52840 NFC tag?

[Lora]

Hi Friends,

I am not yet familiar with NFC and have a question about using NFC with the nRF52.

If I understood it correctly the nRF52 is a "listening device" i.e. it cannot generate a NFC field and write data to another device. But is it possible to send/write data from another device (for example a smartphone, tablette) to the NFC tag of the nRF52.

My Question: Can we differentiate between a polling device and another with the nRF52840 NFC tag? I did a test with an application, i write a Hello! on the nRF52840 NFC tag and I receive this frame 00 0D D1 01 09 54 02 65 6E 48 65 6C 6C 6F 21 63 in debug mode. can i identify a device (polling device) with the nordic SDK? if yes, can you explain to me please.

Thank you for your help .

Best Regards,

Lora 

[Einar Thorsrud]

Hi,

A tag can also both read and write (send and receive) data, but as you noted, but only a reader can set up a field and communicate with tags. As you noted, the nRF can only act as a tag, not a reader.

Can we differentiate between a polling device and another with the nRF52840 NFC tag?

There is no address concept with NFC, so if the data that is exchanged is the same, then they are indistinguishable. On the other hand, if the data differs (say you have a record that is used for that purpose), then it would be possible. This would be application specific, though. For that, maybe you would find this post useful.

[Lora]

Hi Einar Thorsrud ,

Thank you for your feedback .

00 0D                    D1             01 09 54 02 65 6E               48 65 6C 6C 6F 21                63

Length ( Hello!)          ?                             ?                                      Hello!                                              ?

Please can you explain the content of the this frame, or do you have any support that explains the content of the this frame and the meaning of each byte ( By information i wrote a Hello! with an application mobile NFC TOOLS) and i received this frame upon receipt the  NFC_T4T_EVENT_NDEF_UPDATED event.

Thank you again for your help .

Lora

[Einar Thorsrud]

Hi,

There are some tools online that can do this for you. You can take your message ("D1 01 09 54 02 65 6E 48 65 6C 6C 6F 21 63") and copy-past it to this online parser. Then you get all fields explained:

[Lora]

Thank you very very very much for your help  Einar Thorsrud 

[Lora]

Hi Einar,

Can the NFC NRF52840 TAG be secured with a password?

I did a test with NFC TOOLS to set a password but I got an error message "This tag is not yet supported"

Is there a way to add a password to the software listed nRF52840?

Thank you and best regards,

Lora

[Einar Thorsrud]

HI Lora,

I do not know what NFC Tools do with a password. I you want some password mechanism you would have to implement that yourself.