NFC on nRF52840 using nrfx & zephyr t2t tag vs t4t tag

[eshaul]

Hi guys,

I am using the nRF52840 until recently - with the 2t2 library from nrfx - on a Zephyr application over the latest NCS 1.7.1

I wanted to add tag write capabilities.

It seems that the t2t library supports read-only, and to implement write capabilities I will have to switch to t4t - is that correct?

If yes, question is - why?

According to any documentation I found, the type 2 tag has both read/write capabilities - for example:

https://www.dummies.com/consumer-electronics/5-nfc-tag-types/

https://www.electronics-notes.com/articles/connectivity/nfc-near-field-communication/tags-types.php

Am I missing something?

[Mttrinh]

Hi,

Yes, you are correct. Out of the NCS NFC libraries only T4T provides the write capability. We decided to only support the T2T standard in the read-only mode.

There are two option for you:

The easier one will be to switch to T4T (at the cost of higher memory footprint and slower performance - more code to execute) and the more difficult one will be to use RX events directly from the driver, and implement the "WRITE" command on your own.