NTAG 213 Read Procedure

[PDIHawk]

I am implementing my own minimalist code to read a specific address on an NTAG 213 NFC tag.

According to the NFC Tools app on my Android, the data I want is at Address 7.

I have attempted to use the Read command by sending 0x03, 0x30, 0x07, 0x28 (length, command, start, transmission flags) but I have no success.

What is the most efficient way to retrieve the data that I want?

I was also looking into Fast Read but have had no luck with that either.

[PDIHawk]

I figured out how to complete my task without buying the standard.

The tag is in idle mode when it enters the field.  One way to wake it up, is by issuing a REQA command {0x00, 0x04, 0x02, 0x26, 0x07}.  Once it is out of idle, to read address block 7 data, I issue the READ command { 0x00, 0x04, 0x03, 0x30, 0x07, 0x28}.  I was all worried about the CRC but it isn't necessary because the ST25R95 does it for you.  The above sequences are for the ST25R95 complete with the SEND command (0x00) and SENDRECV control (0x04).

[PDIHawk]

Hi Eduardo,

After digging into the datasheet, I understand that I need to issue a REQA or WUPA to get it into the Ready state, then I can issue a memory command.

So I believe for the REQA, I will need to send 0x26, 0x07.

Then for a FAST READ, I will send 0x3A, 0x05, 0x08, 0x8E, 0x51 (command, start address, end address, CRC_A, CRC_A)

I used an online CRC_A calculator on 0x3A0508 and it resulted in 0x8E51, that gave me the last two bytes.

Did I get the CRC calculation correct?

Do I have the correct command strings?

Thanks!

-Andrew

[EduardoZamora]

Hi,

CRC should be calculated according to ISO/IEC 14443 standard. I would recommend you using our NFC Readers in addition to the NFC Reader Library.

NFC Reader Library is a complete software support library for NFC Frontend ICs designed to provide a faster and simpler way to develop your project. This library also provides an API that facilitates the most common operations required in NFC applications such as reading or writing data into contactless cards or tags.

Regards,
Eduardo.

[PDIHawk]

Hi Eduardo,

I don't have access to the ISO/IEC 14443 standard.  Can you check to see if my CRC method is correct?

Is there anyway that you can confirm or deny the commands that I am trying?  If I'm not correct, I would prefer if you could guide me to the correct commands.

I understand that there are other NFC chips and NFC libraries, but that is not where I am in the project.  I have an ST25R95 chip picked and an ATTINY88 processor that can't fit a full library. The ST people have a full library to support the ST25R95 and that would have made it simple too but it will not fit on my Arduino UNO deveopement platform which has alot more space than the ATTINY88.

I don't need all of the functionality of the full library because those libraries are set automatically read any tag.  My project has a narrow scope.  I am only concerned about reading a specific data block of a specific tag.  I have already developed enough routines to do everything that I need except for reading this block of data from this tag.

-Andrew

[EduardoZamora]

Hi,

Since this device is designed to fully comply to NFC Forum Type 2 Tag and ISO/IEC14443 Type A specifications, your reader device should be able to communicate with this tag based on the ISO/IEC 14443 standard, and on the information provided in NTAG213/215/216 Data Sheet Chapter 10 NTAG Commands. Also, you can find the communication flow in Section 8.4 Communication principle.

Unfortunately, we cannot guarantee that you will get the proper response between your devices since you are using some third-party platforms, and the interaction or flow may differ. I will recommend you contacting your reader manufacturer for more information on how to handle data exchange with this tag type.

I will strongly recommend you exploring the possibility of using our NXP Readers.

Please, accept my apologies for any inconvenience this might cause you.

Regards,
Eduardo.

[EduardoZamora]

Hello @PDIHawk

Hope you are doing well.

Please, take a look at the NTAG213/215/216 Data Sheet Chapter 10 NTAG Commands, Section 10.2 READ and Section 10.3 FAST_READ for more information on READ and FAST_READ commands, structure and timing required.

Regards,
Eduardo.