NTAG213 state change when trying to write to protected page?!

[NorbertF]

Hello,

I have a custom board with a CLRC663 plus connected to a STM32 via I2C.

I am using the NFC Reader Library to talk to a NTAG213. Tag detection and read/write is working well.

Then I tried setting lock bytes, which seems to work, as I can't overwrite locked pages and get an error status of 0x0780 from the "phalMful_Write(...)" command.

But after that I get timeouts (0x0201), if I try "Read" or "Get_Version" commands. It looks like the tag changed its state to IDLE, as "REQA" (or "WUPA") command returns success.

The same behaviour applies to password protected pages: after a "Write" the return value is 0x0780 and the tag seems to be in IDLE state.

Is this a bug or a feature I overlooked in the datasheet?

Regards,

Norbert

[Fabian_R]

Hello sir,
Thank you for the clarification.
In case you aren't looking for commands based on NDEF messages, yes it can be used the phalMful, since MIFARE Ultralight complies with parts 2 and 3 of the ISO 14443-A specification.

Now, as you already know we don't have a specific module for NTAGs.
As you mentioned correctly, the phalMful does provide all the required functions for correctly interfacing with the nTags.

The Activity Layer, Discovery Loop has some functions that are very useful, ActivateCard(). But, we also recommend the use of our ISO 14443-3A from the Protocol Abstraction Layer, which has a set of low-level functions that are very useful for nTags as well

The usage of these functions can be easily visualized when RFID Discover is used, please take a look at the attached image.

[NorbertF]

Hello Fabian,

finally I had time to return to this topic:

I use phacDiscLoop_Run(...) to detect the tag.

As far as I found out, this function detects the tag, then does collision resolution and activation of the tag, all by using functions from the 14443p3a layer.

Then I use the MIFARE Ultralight layer to do read and write operations.

If I try to write to a locked page or an out of bounds page, I get a NAK with code 0x0 (see NTAG213 datasheet), which is expected.

But when I try to access the tag again, I get a timeout from the HW layer. The tag has returned to IDLE state, because "REQA" (or "WUPA") command returns success.

Is that a bug or a feature?

In the end, I have to call phacDiscLoop_Run(...)  again, to be able to access the tag again. But that seems wrong to me.

The RFIDDiscover tool I can't use, without getting some HW components to connect to, right?

Regards,

Norbert