NFC APDU Communication Reference Design

[DavideDN]

Hi There,

I am using a nRF52840DK board to experiment with NFC Tag technology.

I started with the "Writable_ndef" example inside the nRFConnect, and it works.

I wrote a simple Android Application too, the app is able to read the tag and to write some data back to the tag.

Now I wish to improve my experimentation in order to exchange more messages among the app and the tag.

Of course one can read the tag and write back data many times using the  "Writable_ndef" approach, but I discovered that the user needs to Tap the tag for each single exchange.

I wish to place the smartphone over the tag and being able to exchange multiple messages without having to tap multiple times.

If I got it correctly the command/response approach for the NFC/Tag technology is obtained using the so called APDU protocol.

Is there some sample project to study an to start with?

I browsed the documentation but I was not able to find something useful. 
I have read the page : https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/libraries/nfc/t4t/apdu.html

The page, at the Api documentation Paragraph, contains a broken link also: docs.nordicsemi.com/.../group__nfc__t4t__apdu.html

Can you help me?

Best Regards 

 Davide De Nardis

[Amanda Hsieh]

Hi, 

I can open the link in the API documentation for APDU reader and writer

https://docs.nordicsemi.com/bundle/nrf-apis-latest/page/group_nfc_t4t_apdu.html 

Regards,
Amanda H.

[DavideDN]

Thank you Amanda,

Now the link to the doc has been fixed and I read it: I am seeing that these pages are the usual docs automatically generated from the source code. It is good to have it.
Anyway a simple use case example would be of great help!
Usually, for these kind of application, there should be a setup-config sequence to follow to initialize the peripheral and the involved libraries, and then some method and callbacks to handle the message exchanges....
And, very important, when using nRFConnect SDK, a detailed description of the required CONFIG_XXX=Whatever (to me the prog.conf area is the second most frustrating aspect of the SDK).

Can you kindly share some hint in writing the correct sequence of functions to call?

br

 Davide De Nardis

[Amanda Hsieh]

You can take a look at this course https://academy.nordicsemi.com/courses/nrf-connect-sdk-fundamentals/lessons/lesson-3-elements-of-an-nrf-connect-sdk-application/ 

[DavideDN]

Thank you, surely I will review the course that covers the SDK configuration.

Since the writable ndef tag example is already working, I believe that my project configuration is already OK.
My difficulties are related to the APDU API.
Is there a small guide to show the philosophy of them? the intended usage? 
I am asking this because looking at the automatic documentation you pointed, I understood that it has nothing to do with the writable_ndef api logic. Init functions, callbacks... all different.

So I am stuck.

Do you have some hint?

Davide

[Amanda Hsieh]

You can just include the API without config. See NFC: Tag reader sample, which uses APDU reader and writer API.