flutterNfcKit.poll issue

[Saintqqq]

hi
im using ios / 15693 tag
My block 0 is E2 40 00 01, declaring it as an NDEF tag. However, my block 1 is (00 00 03 FF), which is an incomplete NDEF data format.

This causes NFCTag tag = await FlutterNfcKit.poll();
to fail, as it cannot detect the tag. What should I do? I need to rewrite clean NDEF data to make it work properly.

Although I declared the tag as NDEF in block 0, the data is not necessarily in NDEF format. I still need NFCTag tag = await FlutterNfcKit.poll(); to be able to read the tag.

Is there a way to avoid polling specifically for NDEF tags and instead detect any type of tag?

thanks

[Harry-Chen]

We are already using the general NFCTagReaderSession on iOS. According to my understanding of CoreNFC APIs, there is not much we could do to control its behavior. If CoreNFC thinks it's NDEF, it will try to read & decode NDEF.

[robertpoll]

As I understand it 0xE2 in the first byte of block 0 signifies an 8 byte CC so your NDEF TLV header starts at block 2. The 8 byte CC looks good for an 8kB tag (maybe ST25DV64?). We can't see the TLV in block 2+ but assume it's invalid as you say. In my use case if I overwrite the TLV with invalid data on iOS poll() still returns the tag and allows a subsequent transceive() to be successfully sent so you should be able to write a valid NDEF record immediately following the poll(). This is assuming you're on iOS. If you're on Android then poll() will try to read the NDEF and you'll get an error - I've just submitted a PR #225 that allows you to disable the NDEF read on Android poll() using readerModeFlags which may fix your problem.