NT3H2111 stack error

[juyoung]

I have developed a cross-platform flutter app that can scan NT3H2111 and write some data back to the tag. 

I noticed when the tag gets lost during scanning, it gives stack error in subsequent scans in ios whereas in android it doesn't.

 Do you know what I can do to fix this?

[juyoung]

Hi Julian, 

The error I am getting is [Core NFC] [NFCMiFareTag queryNDEFStatusWithCompletionHandler:]:210 Error=Error Domain=NFCError Code=104 "Stack Error" UserInfo={NSLocalizedDescription=Stack Error, NSUnderlyingError=0x28236b0c0.

I get this error when I make Tag lost error by removing the phone away from the tag during scan followed by a good proper scan. If I repeat this about 10 times I get this stack error. 

I tested with NXP TagInfo app and I don't see the stack error happening partly because I don't have access to the debugging environment. I wouldn't know if the stack error has occurred. Is it possible to get the source code for this?

The cards are not formatted as NDEF.

[Julián_AragónM]

Hi @juyoung,

Please try scanning the tag again with the NDEF format. iOS has the infrastructure to read any HF tag, but it is currently limited to NDEF messages.

You can find more information (which NDEF is supported) through the documentation of Developer Apple: Adding Support for Background Tag Reading.

I hope you find this helpful!

Best regards,
Julián.

[juyoung]

Hi Julian,

I am not very familiar with the NDEF format.

The tag already contains some data in sram which I use to read and write during passthrough mode.

If I format it in NDEF will the data be erased?

Can I get access to the TagInfo app for ios so I can test if it also produces a stack error?

[juyoung]

Could you please check if my info.plist is correct/same as TagInfo app?

My NFC chip is NTAG I2C Plus iso-14443-3A Type A.

<key>NFCReaderUsageDescription</key>

<string>App uses the NFC NDEF reader to read a device</string>

<key>com.apple.developer.nfc.readersession.formats</key>

<string>TAG</string>

<key>com.apple.developer.nfc.readersession.iso7816.select-identifiers</key>

<array>

<string>D2760000850101</string>

<string>D2760000850100</string>

</array>

<key>NFC Scan Usage Description</key>

<string>Need to scan a tag</string>

[Julián_AragónM]

Hi @juyoung,

NDEF is a standardized data format which allows a smartphone to read or write on an NFC card or an NFC tag, formatting the tag will erase the previous data, but you can just replace it with the same data in the NDEF format. The Tag Writer app has a built in "Format" action, which can be used as a reference on how to format the messages.

As for the Tag Info app, unfortunately, the source code is not available for public sharing, I apologize for any inconveniences this may cause.

You can look into these community posts for more information about NDEF:

• When to use NDEF and when not to - NXP Community
• Solved: How does an nfc tag where to save the NDEF-message... - NXP Community

Best regards,
Julián.

[Julián_AragónM]

Hi @juyoung,

Could you please provide a bit more information about the project as well as the error?

What is the stack error shown in iOS? Have you tested the tags are being read correctly by another app in iOS (like Tag Writer)? Are the cards formatted as NDEF or are they blank? 

We have some resources for mobile development (although iOS is limited) through here: RFID Developer Resources.

Best regards,
Julián.